(/* Implantable Cardioverter-Defibrillators{{cite journal |author=Epstein AE, DiMarco JP, Ellenbogen KA, et al |title=ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities: a report of the American College of Cardiolo...)
''Morphology discrimination'' checks the morphology of every ventricular beat and compares it to what the ICD believes is a normally conducted ventricular impulse for the patient. This normal ventricular impulse is often an average of a multiple of beats of the patient taken in the recent past.
''Morphology discrimination'' checks the morphology of every ventricular beat and compares it to what the ICD believes is a normally conducted ventricular impulse for the patient. This normal ventricular impulse is often an average of a multiple of beats of the patient taken in the recent past.
[[Image:Torsades converted by AICD ECG strip Lead II.JPG|thumb|left|650px|Lead II [[electrocardiogram]] showing [[Torsades]] being shocked by an implantable cardioverter-defibrillator back to the patient's baseline [[cardiac rhythm]].]]
[[Image:Torsades converted by AICD ECG strip Lead II.JPG|thumb|right|650px|Lead II [[electrocardiogram]] showing [[Torsades]] being shocked by an implantable cardioverter-defibrillator back to the patient's baseline [[cardiac rhythm]].]]
==History==
The development of the ICD was pioneered at [[Sinai Hospital]] in Baltimore by a team including [[Michel Mirowski]], Morton Mower, and William Staewen.<ref>Mirowski M, Mower MM, Staewen WS, et al: Standby automatic defibrillator: An approach to prevention of sudden coronary death. Arch Intern Med 126:158-161, 1970</ref> Mirowski teamed up with Mower and Staewen and together they commenced their research in 1969 but it was 11 years before they treated their first patient. Similar developmental work was carried out almost coincidentally by Schuder and colleagues at the University of Missouri.
More than a decade of research went into the development of an implantable defibrillator that would automatically sense the onset of ventricular fibrillation and deliver an electric countershock within 15–20 seconds, converting the rhythm to [[sinus rhythm]]. Improved versions were programmed to be able to detect ventricular tachycardia, often a forerunner of ventricular fibrillation. These were then called implantable cardioverters.
The work was commenced against much skepticism even by leading experts in the field of arrhythmias and sudden death. There was doubt that their ideas would ever become a clinical reality. In 1972 [[Bernard Lown]], the inventor of the external [[defibrillator]], stated in the journal ''[[Circulation (journal)|Circulation]]'' - "The very rare patient who has frequent bouts of ventricular fibrillation is best treated in a coronary care unit and is better served by an effective antiarrhythmic program or surgical correction of inadequate coronary blood flow or ventricular malfunction. In fact, the implanted defibrillator system represents an imperfect solution in search of a plausible and practical application".
The problems to be overcome were the design of a system which would allow detection of ventricular fibrillation or ventricular tachycardia. Despite the lack of financial backing and grants, they persisted and the first device was implanted in February 1980 at [[Johns Hopkins Hospital]] by Dr. Levi Watkins, Jr. Modern ICDs do not require a [[thoracotomy]] and possess pacing, cardioversion, and defibrillation capabilities.
Internal cardioverter defibrillators have also been used twice in dogs to prevent sudden death from arrhythmia. The first defibrillator was implanted at Washington State University by a team of cardiologists led by Dr Lynne Johnson in 2003. The patient was a Boxer dog with life threatening arrhythmias from arrhythmogenic right ventricular cardiomyopathy, an inherited disease. On July 21, 2008, a second ICD was implanted in a 6-month-old German Shepherd dog with inherited ventricular arrhythmias. The 5-hour long surgery took place at Louisiana State University and was led by Dr Romain Pariaut. So far, these pets are the only two client-owned dogs that have received such a high-tech treatment.
:* 1.1. '''Early post-implantation inflammation'''<ref name="pmid25355810">{{cite journal| author=Sandoe JA, Barlow G, Chambers JB, Gammage M, Guleri A, Howard P et al.| title=Guidelines for the diagnosis, prevention and management of implantable cardiac electronic device infection. Report of a joint Working Party project on behalf of the British Society for Antimicrobial Chemotherapy (BSAC, host organization), British Heart Rhythm Society (BHRS), British Cardiovascular Society (BCS), British Heart Valve Society (BHVS) and British Society for Echocardiography (BSE). | journal=J Antimicrob Chemother | year= 2015 | volume= 70 | issue= 2 | pages= 325-59 | pmid=25355810 | doi=10.1093/jac/dku383 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=25355810 }} </ref><ref name="pmid25550318">{{cite journal| author=Harrison JL, Prendergast BD, Sandoe JA| title=Guidelines for the diagnosis, management and prevention of implantable cardiac electronic device infection. | journal=Heart | year= 2015 | volume= 101 | issue= 4 | pages= 250-2 | pmid=25550318 | doi=10.1136/heartjnl-2014-306873 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=25550318 }} </ref><ref name="pmid20048212">{{cite journal| author=Baddour LM, Epstein AE, Erickson CC, Knight BP, Levison ME, Lockhart PB et al.| title=Update on cardiovascular implantable electronic device infections and their management: a scientific statement from the American Heart Association. | journal=Circulation | year= 2010 | volume= 121 | issue= 3 | pages= 458-77 | pmid=20048212 | doi=10.1161/CIRCULATIONAHA.109.192665 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=20048212 }} </ref>
::* Preferred regimen: [[Flucloxacillin]] 0.5–1 g PO tid
:* 1.2. '''Penicillin allergy or MRSA Colonisation'''
::* Preferred regimen: [[Doxycycline]] 100 mg PO bid {{or}} [[Linezolid]] 600 mg PO bid {{or}} [[Clindamycin]] 450 mg po qid
::* Note: Benefit of and need for antimicrobial therapy in early post-implantation [[inflammation]] is unclear.
:* 1.3. '''Early post-implantation inflammation in penicillin-allergic or MRSA-colonized patient'''
::* Preferred regimen: [[Doxycycline]] 100 mg PO bid {{or}} [[Linezolid]] 600 mg PO bid {{or}} [[Clindamycin]] 450 mg PO qid
::* Preferred regimen: [[Vancomycin]] 1 g IV q12h {{or}} [[Daptomycin]] 4 mg/kg IV qd {{or}} [[Teicoplanin]] 6 mg/kg to a maximum of 1 g IV given at 0, 12 and 24 h and then qd
:* 1.5. '''ICED-LI or ICED-IE or complicated generator pocket infection pending blood cultures, e.g. in severe sepsis'''
::* Preferred regimen: [[Vancomycin]] 1 g IV q12h {{and}} [[Meropenem]] 1 g IV q8h {{or}} [[Daptomycin]] 8–10 mg/kg IV qd {{and}} [[Meropenem]] 1 g IV q8h
::* Note: [[Gentamicin]] or other anti-Gram-negative agents may be appropriate depending on local epidemiology.
:* 1.6. '''ICED-LI or ICED-IE or generator pocket infection with negative blood cultures'''
::* Preferred regimen: [[Vancomycin]] 1 g IV q12h {{and}} [[Gentamicin]] 1 mg/kg IV q12h {{or}} [[Daptomycin]] 8–10 mg/kg IV qd {{and}} [[Gentamicin]] 1 mg/kg [[IV]] q12h
::* Note: Duration of antimicrobial therapy should be at least 4 to 6 weeks for complicated [[infection]] (ie, [[endocarditis]], [[septic thrombophlebitis]], or [[osteomyelitis]] or if bloodstream [[infection]] persists despite device removal and appropriate initial antimicrobial therapy.
----
==History==
==Causes==
The development of the ICD was pioneered at [[Sinai Hospital]] in [[Baltimore]] by a team including [[Michel Mirowski]], [[Morton Mower]], and William Staewen.<ref>Mirowski M, Mower MM, Staewen WS, et al: Standby automatic defibrillator: An approach to prevention of sudden coronary death. Arch Intern Med 126:158-161, 1970</ref> Mirowski teamed up with Mower and Staewen and together they commenced their research in 1969 but it was 11 years before they treated their first patient. Similar developmental work was carried out almost coincidentally by Schuder and colleagues at the [[University of Missouri]].
===Common Causes===
*[[staphylococcus|Coagulase-negative staphylococcus]] <ref name="BaddourEpstein2010">{{cite journal|last1=Baddour|first1=L. M.|last2=Epstein|first2=A. E.|last3=Erickson|first3=C. C.|last4=Knight|first4=B. P.|last5=Levison|first5=M. E.|last6=Lockhart|first6=P. B.|last7=Masoudi|first7=F. A.|last8=Okum|first8=E. J.|last9=Wilson|first9=W. R.|last10=Beerman|first10=L. B.|last11=Bolger|first11=A. F.|last12=Estes|first12=N. A. M.|last13=Gewitz|first13=M.|last14=Newburger|first14=J. W.|last15=Schron|first15=E. B.|last16=Taubert|first16=K. A.|title=Update on Cardiovascular Implantable Electronic Device Infections and Their Management: A Scientific Statement From the American Heart Association|journal=Circulation|volume=121|issue=3|year=2010|pages=458–477|issn=0009-7322|doi=10.1161/CIRCULATIONAHA.109.192665}}</ref><ref name="SohailUslan2007">{{cite journal|last1=Sohail|first1=Muhammad R.|last2=Uslan|first2=Daniel Z.|last3=Khan|first3=Akbar H.|last4=Friedman|first4=Paul A.|last5=Hayes|first5=David L.|last6=Wilson|first6=Walter R.|last7=Steckelberg|first7=James M.|last8=Stoner|first8=Sarah|last9=Baddour|first9=Larry M.|title=Management and Outcome of Permanent Pacemaker and Implantable Cardioverter-Defibrillator Infections|journal=Journal of the American College of Cardiology|volume=49|issue=18|year=2007|pages=1851–1859|issn=07351097|doi=10.1016/j.jacc.2007.01.072}}</ref>
*[[Staphylococcus aureus]] <ref name="SohailUslan2007">{{cite journal|last1=Sohail|first1=Muhammad R.|last2=Uslan|first2=Daniel Z.|last3=Khan|first3=Akbar H.|last4=Friedman|first4=Paul A.|last5=Hayes|first5=David L.|last6=Wilson|first6=Walter R.|last7=Steckelberg|first7=James M.|last8=Stoner|first8=Sarah|last9=Baddour|first9=Larry M.|title=Management and Outcome of Permanent Pacemaker and Implantable Cardioverter-Defibrillator Infections|journal=Journal of the American College of Cardiology|volume=49|issue=18|year=2007|pages=1851–1859|issn=07351097|doi=10.1016/j.jacc.2007.01.072}}</ref>
*[[Staphylococcus epidermidis]]
More than a decade of research went into the development of an implantable defibrillator that would automatically sense the onset of ventricular fibrillation and deliver an electric countershock within 15–20 seconds, converting the rhythm to [[sinus rhythm]]. Improved versions were programmed to be able to detect ventricular tachycardia, often a forerunner of ventricular fibrillation. These were then called implantable cardioverters.
The work was commenced against much skepticism even by leading experts in the field of arrhythmias and sudden death. There was doubt that their ideas would ever become a clinical reality. In 1972 [[Bernard Lown]], the inventor of the external [[defibrillator]], stated in the journal ''[[Circulation (journal)|Circulation]]'' - "The very rare patient who has frequent bouts of ventricular fibrillation is best treated in a coronary care unit and is better served by an effective antiarrhythmic program or surgical correction of inadequate coronary blood flow or ventricular malfunction. In fact, the implanted defibrillator system represents an imperfect solution in search of a plausible and practical application".
==Living with an ICD==
The problems to be overcome were the design of a system which would allow detection of ventricular fibrillation or ventricular tachycardia. Despite the lack of financial backing and grants, they persisted and the first device was implanted in February 1980 at [[Johns Hopkins Hospital]] by Dr. Levi Watkins, Jr. Modern ICDs do not require a [[thoracotomy]] and possess pacing, cardioversion, and defibrillation capabilities.
Internal cardioverter defibrillators have also been used twice in dogs to prevent sudden death from arrhythmia. The first defibrillator was implanted at Washington State University by a team of cardiologists led by Dr Lynne Johnson in 2003. The patient was a Boxer dog with life threatening arrhythmias from arrhythmogenic right ventricular cardiomyopathy, an inherited disease. On July 21, 2008, a second ICD was implanted in a 6-month-old German Shepherd dog with inherited ventricular arrhythmias. The 5-hour long surgery took place at Louisiana State University and was led by Dr Romain Pariaut. So far, these pets are the only two client-owned dogs that have received such a high-tech treatment.
==Living with an ICD==
[[Image:Implantable cardioverter defibrillator chest X-ray.jpg|thumb|A normal chest X-ray after placement of an ICD, showing the ICD generator in the upper left chest and the ICD lead in the right ventricle of the heart. Note the 2 opaque coils along the ICD lead.]]
People that have an implanted cardioverter-defibrillator can live full and happy lives. Usually the ICD improves the living conditions of a patient significantly. As with a pacemaker, living with an ICD does impose some restrictions on the person's lifestyle.
People that have an implanted cardioverter-defibrillator can live full and happy lives. Usually the ICD improves the living conditions of a patient significantly. As with a pacemaker, living with an ICD does impose some restrictions on the person's lifestyle.
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A recent study by Birnie et al. at the University of Ottawa Heart Institute has demonstrated that ICDs are underused in both the United States and Canada.<ref>{{cite journal|url=http://www.cmaj.ca/cgi/reprint/177/1/41|journal=Canadian Medical Association Journal|title=Use of implantable cardioverter defibrillators in Canadian and IS survivors of out-of-hospital cardiac arrest|last=Birnie|first=David H|coauthors=Sambell, Christie; Johansen, Helen; Williams, Katherine; Lemery, Robert; Green, Martin S; Gollob, Michael H; Lee, Douglas S; Tang, Anthony SL|accessdate=2007-07-29|month=July | year=2007|volume=177|issue=1|doi=10.1503/cmaj.060730|pages=41|pmid=17606938|pmc=1896034}}</ref> An accompanying editorial by Dr. Chris Simpson of Queen's University explores some of the economic, geographic, social and political reasons for this.<ref>{{cite journal|url=http://www.cmaj.ca/cgi/reprint/177/1/49|title=Implantable cardioverter defibrillators work - so why aren't we using them?|last=Simpson|first=Christopher S|journal=Canadian Medical Association Journal|month=July | year=2007|accessdate=2007-07-29|volume=177|issue=1|doi=10.1503/cmaj.070470|pages=49|pmid=17606939|pmc=1896028}}</ref>
A recent study by Birnie et al. at the University of Ottawa Heart Institute has demonstrated that ICDs are underused in both the United States and Canada.<ref>{{cite journal|url=http://www.cmaj.ca/cgi/reprint/177/1/41|journal=Canadian Medical Association Journal|title=Use of implantable cardioverter defibrillators in Canadian and IS survivors of out-of-hospital cardiac arrest|last=Birnie|first=David H|coauthors=Sambell, Christie; Johansen, Helen; Williams, Katherine; Lemery, Robert; Green, Martin S; Gollob, Michael H; Lee, Douglas S; Tang, Anthony SL|accessdate=2007-07-29|month=July | year=2007|volume=177|issue=1|doi=10.1503/cmaj.060730|pages=41|pmid=17606938|pmc=1896034}}</ref> An accompanying editorial by Dr. Chris Simpson of Queen's University explores some of the economic, geographic, social and political reasons for this.<ref>{{cite journal|url=http://www.cmaj.ca/cgi/reprint/177/1/49|title=Implantable cardioverter defibrillators work - so why aren't we using them?|last=Simpson|first=Christopher S|journal=Canadian Medical Association Journal|month=July | year=2007|accessdate=2007-07-29|volume=177|issue=1|doi=10.1503/cmaj.070470|pages=49|pmid=17606939|pmc=1896028}}</ref>
==2008 ACC/AHA/HRS Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities (DO NOT EDIT)<ref name="pmid18483207">{{cite journal |author=Epstein AE, DiMarco JP, Ellenbogen KA, ''et al'' |title=ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the ACC/AHA/NASPE 2002 Guideline Update for Implantation of Cardiac Pacemakers and Antiarrhythmia Devices): developed in collaboration with the American Association for Thoracic Surgery and Society of Thoracic Surgeons |journal=Circulation |volume=117 |issue=21 |pages=e350-408 |year=2008 |month=May |pmid=18483207 |doi:10.1161/CIRCUALTIONAHA.108.189742 |url=}}</ref>==
===Implantable Cardioverter-Defibrillators<ref name="pmid18483207">{{cite journal |author=Epstein AE, DiMarco JP, Ellenbogen KA, ''et al'' |title=ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the ACC/AHA/NASPE 2002 Guideline Update for Implantation of Cardiac Pacemakers and Antiarrhythmia Devices): developed in collaboration with the American Association for Thoracic Surgery and Society of Thoracic Surgeons |journal=Circulation |volume=117 |issue=21 |pages=e350-408 |year=2008 |month=May |pmid=18483207 |doi:10.1161/CIRCUALTIONAHA.108.189742 |url=}}</ref>===
{|class="wikitable"
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| colspan="1" style="text-align:center; background:LightGreen"|[[ACC AHA guidelines classification scheme#Classification of Recommendations|Class I]]
|-
| bgcolor="LightGreen"|<nowiki>"</nowiki>'''1.''' [[ICD therapy]] is indicated in patients who are survivors of [[cardiac arrest]] due to [[ventricular fibrillation]] or hemodynamically unstable sustained [[VT]] after evaluation to define the cause of the event and to exclude any completely reversible causes. ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: A]])''<ref name="pmid16949478">{{cite journal| author=European Heart Rhythm Association. Heart Rhythm Society. Zipes DP, Camm AJ, Borggrefe M, Buxton AE et al.| title=ACC/AHA/ESC 2006 guidelines for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death: a report of the American College of Cardiology/American Heart Association Task Force and the European Society of Cardiology Committee for Practice Guidelines (Writing Committee to Develop Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death). | journal=J Am Coll Cardiol | year= 2006 | volume= 48 | issue= 5 | pages= e247-346 | pmid=16949478 | doi=10.1016/j.jacc.2006.07.010 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=16949478 }} </ref><ref name="pmid9411221">{{cite journal| author=| title=A comparison of antiarrhythmic-drug therapy with implantable defibrillators in patients resuscitated from near-fatal ventricular arrhythmias. The Antiarrhythmics versus Implantable Defibrillators (AVID) Investigators. | journal=N Engl J Med | year= 1997 | volume= 337 | issue= 22 | pages= 1576-83 | pmid=9411221 | doi=10.1056/NEJM199711273372202 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=9411221 }} </ref><ref name="pmid7697849">{{cite journal| author=Wever EF, Hauer RN, van Capelle FL, Tijssen JG, Crijns HJ, Algra A et al.| title=Randomized study of implantable defibrillator as first-choice therapy versus conventional strategy in postinfarct sudden death survivors. | journal=Circulation | year= 1995 | volume= 91 | issue= 8 | pages= 2195-203 | pmid=7697849 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=7697849 }} </ref><ref name="pmid8160593">{{cite journal| author=Siebels J, Kuck KH| title=Implantable cardioverter defibrillator compared with antiarrhythmic drug treatment in cardiac arrest survivors (the Cardiac Arrest Study Hamburg). | journal=Am Heart J | year= 1994 | volume= 127 | issue= 4 Pt 2 | pages= 1139-44 | pmid=8160593 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=8160593 }} </ref><ref name="pmid10725290">{{cite journal| author=Connolly SJ, Gent M, Roberts RS, Dorian P, Roy D, Sheldon RS et al.| title=Canadian implantable defibrillator study (CIDS) : a randomized trial of the implantable cardioverter defibrillator against amiodarone. | journal=Circulation | year= 2000 | volume= 101 | issue= 11 | pages= 1297-302 | pmid=10725290 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=10725290 }} </ref><ref name="pmid10942742">{{cite journal| author=Kuck KH, Cappato R, Siebels J, Rüppel R| title=Randomized comparison of antiarrhythmic drug therapy with implantable defibrillators in patients resuscitated from cardiac arrest : the Cardiac Arrest Study Hamburg (CASH). | journal=Circulation | year= 2000 | volume= 102 | issue= 7 | pages= 748-54 | pmid=10942742 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=10942742 }} </ref><ref name="pmid11102258">{{cite journal| author=Connolly SJ, Hallstrom AP, Cappato R, Schron EB, Kuck KH, Zipes DP et al.| title=Meta-analysis of the implantable cardioverter defibrillator secondary prevention trials. AVID, CASH and CIDS studies. Antiarrhythmics vs Implantable Defibrillator study. Cardiac Arrest Study Hamburg . Canadian Implantable Defibrillator Study. | journal=Eur Heart J | year= 2000 | volume= 21 | issue= 24 | pages= 2071-8 | pmid=11102258 | doi=10.1053/euhj.2000.2476 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=11102258 }} </ref><nowiki>"</nowiki>
|-
| bgcolor="LightGreen"|<nowiki>"</nowiki>'''2.''' ICD therapy is indicated in patients with structural heart disease and spontaneous sustained VT, whether hemodynamically stable or unstable. ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: B]])''<ref name="pmid16949478">{{cite journal| author=European Heart Rhythm Association. Heart Rhythm Society. Zipes DP, Camm AJ, Borggrefe M, Buxton AE et al.| title=ACC/AHA/ESC 2006 guidelines for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death: a report of the American College of Cardiology/American Heart Association Task Force and the European Society of Cardiology Committee for Practice Guidelines (Writing Committee to Develop Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death). | journal=J Am Coll Cardiol | year= 2006 | volume= 48 | issue= 5 | pages= e247-346 | pmid=16949478 | doi=10.1016/j.jacc.2006.07.010 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=16949478 }} </ref><ref name="pmid9411221">{{cite journal| author=| title=A comparison of antiarrhythmic-drug therapy with implantable defibrillators in patients resuscitated from near-fatal ventricular arrhythmias. The Antiarrhythmics versus Implantable Defibrillators (AVID) Investigators. | journal=N Engl J Med | year= 1997 | volume= 337 | issue= 22 | pages= 1576-83 | pmid=9411221 | doi=10.1056/NEJM199711273372202 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=9411221 }} </ref><ref name="pmid7697849">{{cite journal| author=Wever EF, Hauer RN, van Capelle FL, Tijssen JG, Crijns HJ, Algra A et al.| title=Randomized study of implantable defibrillator as first-choice therapy versus conventional strategy in postinfarct sudden death survivors. | journal=Circulation | year= 1995 | volume= 91 | issue= 8 | pages= 2195-203 | pmid=7697849 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=7697849 }} </ref><ref name="pmid8160593">{{cite journal| author=Siebels J, Kuck KH| title=Implantable cardioverter defibrillator compared with antiarrhythmic drug treatment in cardiac arrest survivors (the Cardiac Arrest Study Hamburg). | journal=Am Heart J | year= 1994 | volume= 127 | issue= 4 Pt 2 | pages= 1139-44 | pmid=8160593 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=8160593 }} </ref><ref name="pmid10725290">{{cite journal| author=Connolly SJ, Gent M, Roberts RS, Dorian P, Roy D, Sheldon RS et al.| title=Canadian implantable defibrillator study (CIDS) : a randomized trial of the implantable cardioverter defibrillator against amiodarone. | journal=Circulation | year= 2000 | volume= 101 | issue= 11 | pages= 1297-302 | pmid=10725290 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=10725290 }} </ref><ref name="pmid10942742">{{cite journal| author=Kuck KH, Cappato R, Siebels J, Rüppel R| title=Randomized comparison of antiarrhythmic drug therapy with implantable defibrillators in patients resuscitated from cardiac arrest : the Cardiac Arrest Study Hamburg (CASH). | journal=Circulation | year= 2000 | volume= 102 | issue= 7 | pages= 748-54 | pmid=10942742 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=10942742 }} </ref><ref name="pmid11102258">{{cite journal| author=Connolly SJ, Hallstrom AP, Cappato R, Schron EB, Kuck KH, Zipes DP et al.| title=Meta-analysis of the implantable cardioverter defibrillator secondary prevention trials. AVID, CASH and CIDS studies. Antiarrhythmics vs Implantable Defibrillator study. Cardiac Arrest Study Hamburg . Canadian Implantable Defibrillator Study. | journal=Eur Heart J | year= 2000 | volume= 21 | issue= 24 | pages= 2071-8 | pmid=11102258 | doi=10.1053/euhj.2000.2476 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=11102258 }} </ref><nowiki>"</nowiki>
|-
| bgcolor="LightGreen"|<nowiki>"</nowiki>'''3.''' ICD therapy is indicated in patients with syncope of undetermined origin with clinically relevant, hemodynamically significant sustained VT or ventricular fibrillation induced at electrophysiological study. ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: B]])''<ref name="pmid16949478">{{cite journal| author=European Heart Rhythm Association. Heart Rhythm Society. Zipes DP, Camm AJ, Borggrefe M, Buxton AE et al.| title=ACC/AHA/ESC 2006 guidelines for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death: a report of the American College of Cardiology/American Heart Association Task Force and the European Society of Cardiology Committee for Practice Guidelines (Writing Committee to Develop Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death). | journal=J Am Coll Cardiol | year= 2006 | volume= 48 | issue= 5 | pages= e247-346 | pmid=16949478 | doi=10.1016/j.jacc.2006.07.010 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=16949478 }} </ref><ref name="pmid10725290">{{cite journal| author=Connolly SJ, Gent M, Roberts RS, Dorian P, Roy D, Sheldon RS et al.| title=Canadian implantable defibrillator study (CIDS) : a randomized trial of the implantable cardioverter defibrillator against amiodarone. | journal=Circulation | year= 2000 | volume= 101 | issue= 11 | pages= 1297-302 | pmid=10725290 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=10725290 }} </ref><nowiki>"</nowiki>
|-
| bgcolor="LightGreen"|<nowiki>"</nowiki>'''4.''' ICD therapy is indicated in patients with LVEF less than or equal to 35% due to prior [[myocardial infarction]] who are at least 40 days post–myocardial infarction and are in [[NYHA]] functional Class II or III. ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: A]])''<ref name="pmid16949478">{{cite journal| author=European Heart Rhythm Association. Heart Rhythm Society. Zipes DP, Camm AJ, Borggrefe M, Buxton AE et al.| title=ACC/AHA/ESC 2006 guidelines for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death: a report of the American College of Cardiology/American Heart Association Task Force and the European Society of Cardiology Committee for Practice Guidelines (Writing Committee to Develop Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death). | journal=J Am Coll Cardiol | year= 2006 | volume= 48 | issue= 5 | pages= e247-346 | pmid=16949478 | doi=10.1016/j.jacc.2006.07.010 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=16949478 }} </ref><ref name="pmid15659722">{{cite journal| author=Bardy GH, Lee KL, Mark DB, Poole JE, Packer DL, Boineau R et al.| title=Amiodarone or an implantable cardioverter-defibrillator for congestive heart failure. | journal=N Engl J Med | year= 2005 | volume= 352 | issue= 3 | pages= 225-37 | pmid=15659722 | doi=10.1056/NEJMoa043399 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15659722 }} [http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15989294 Review in: ACP J Club. 2005 Jul-Aug;143(1):6] </ref><nowiki>"</nowiki>
|-
| bgcolor="LightGreen"|<nowiki>"</nowiki>'''5.''' ICD therapy is indicated in patients with nonischemic [[dilated cardiomyopathy]] who have an LVEF less than or equal to 35% and who are in NYHA functional Class II or III. ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: B]])''<ref name="pmid16949478">{{cite journal| author=European Heart Rhythm Association. Heart Rhythm Society. Zipes DP, Camm AJ, Borggrefe M, Buxton AE et al.| title=ACC/AHA/ESC 2006 guidelines for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death: a report of the American College of Cardiology/American Heart Association Task Force and the European Society of Cardiology Committee for Practice Guidelines (Writing Committee to Develop Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death). | journal=J Am Coll Cardiol | year= 2006 | volume= 48 | issue= 5 | pages= e247-346 | pmid=16949478 | doi=10.1016/j.jacc.2006.07.010 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=16949478 }} </ref><ref name="pmid15659722">{{cite journal| author=Bardy GH, Lee KL, Mark DB, Poole JE, Packer DL, Boineau R et al.| title=Amiodarone or an implantable cardioverter-defibrillator for congestive heart failure. | journal=N Engl J Med | year= 2005 | volume= 352 | issue= 3 | pages= 225-37 | pmid=15659722 | doi=10.1056/NEJMoa043399 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15659722 }} [http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15989294 Review in: ACP J Club. 2005 Jul-Aug;143(1):6] </ref><ref name="pmid15152060">{{cite journal| author=Kadish A, Dyer A, Daubert JP, Quigg R, Estes NA, Anderson KP et al.| title=Prophylactic defibrillator implantation in patients with nonischemic dilated cardiomyopathy. | journal=N Engl J Med | year= 2004 | volume= 350 | issue= 21 | pages= 2151-8 | pmid=15152060 | doi=10.1056/NEJMoa033088 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15152060 }} [http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15518445 Review in: ACP J Club. 2004 Nov-Dec;141(3):61] </ref><ref name="pmid15598919">{{cite journal| author=Desai AS, Fang JC, Maisel WH, Baughman KL| title=Implantable defibrillators for the prevention of mortality in patients with nonischemic cardiomyopathy: a meta-analysis of randomized controlled trials. | journal=JAMA | year= 2004 | volume= 292 | issue= 23 | pages= 2874-9 | pmid=15598919 | doi=10.1001/jama.292.23.2874 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15598919 }} [http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15862056 Review in: ACP J Club. 2005 May-Jun;142(3):57] </ref><nowiki>"</nowiki>
|-
| bgcolor="LightGreen"|<nowiki>"</nowiki>'''6.''' ICD therapy is indicated in patients with [[LV dysfunction]] due to prior myocardial infarction who are at least 40 days post- myocardial infarction, have an LVEF less than or equal to 30%, and are in NYHA functional Class I. ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: A]])''<ref name="pmid16949478">{{cite journal| author=European Heart Rhythm Association. Heart Rhythm Society. Zipes DP, Camm AJ, Borggrefe M, Buxton AE et al.| title=ACC/AHA/ESC 2006 guidelines for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death: a report of the American College of Cardiology/American Heart Association Task Force and the European Society of Cardiology Committee for Practice Guidelines (Writing Committee to Develop Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death). | journal=J Am Coll Cardiol | year= 2006 | volume= 48 | issue= 5 | pages= e247-346 | pmid=16949478 | doi=10.1016/j.jacc.2006.07.010 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=16949478 }} </ref><ref name="pmid11907286">{{cite journal| author=Moss AJ, Zareba W, Hall WJ, Klein H, Wilber DJ, Cannom DS et al.| title=Prophylactic implantation of a defibrillator in patients with myocardial infarction and reduced ejection fraction. | journal=N Engl J Med | year= 2002 | volume= 346 | issue= 12 | pages= 877-83 | pmid=11907286 | doi=10.1056/NEJMoa013474 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=11907286 }} [http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=12418821 Review in: ACP J Club. 2002 Nov-Dec;137(3):81] </ref><nowiki>"</nowiki>
|-
| bgcolor="LightGreen"|<nowiki>"</nowiki>'''7.''' ICD therapy is indicated in patients with nonsustained VT due to prior myocardial infarction, LVEF less than or equal to40%, and inducible ventricular fibrillation or sustained VT at electrophysiological study. ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: B]])''<ref name="pmid16949478">{{cite journal| author=European Heart Rhythm Association. Heart Rhythm Society. Zipes DP, Camm AJ, Borggrefe M, Buxton AE et al.| title=ACC/AHA/ESC 2006 guidelines for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death: a report of the American College of Cardiology/American Heart Association Task Force and the European Society of Cardiology Committee for Practice Guidelines (Writing Committee to Develop Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death). | journal=J Am Coll Cardiol | year= 2006 | volume= 48 | issue= 5 | pages= e247-346 | pmid=16949478 | doi=10.1016/j.jacc.2006.07.010 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=16949478 }} </ref><ref name="pmid10601507">{{cite journal| author=Buxton AE, Lee KL, Fisher JD, Josephson ME, Prystowsky EN, Hafley G| title=A randomized study of the prevention of sudden death in patients with coronary artery disease. Multicenter Unsustained Tachycardia Trial Investigators. | journal=N Engl J Med | year= 1999 | volume= 341 | issue= 25 | pages= 1882-90 | pmid=10601507 | doi=10.1056/NEJM199912163412503 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=10601507 }} </ref><ref name="pmid8960472">{{cite journal| author=Moss AJ, Hall WJ, Cannom DS, Daubert JP, Higgins SL, Klein H et al.| title=Improved survival with an implanted defibrillator in patients with coronary disease at high risk for ventricular arrhythmia. Multicenter Automatic Defibrillator Implantation Trial Investigators. | journal=N Engl J Med | year= 1996 | volume= 335 | issue= 26 | pages= 1933-40 | pmid=8960472 | doi=10.1056/NEJM199612263352601 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=8960472 }} </ref><nowiki>"</nowiki>
|}
{|class="wikitable"
|-
| colspan="1" style="text-align:center; background:LightCoral"|[[ACC AHA guidelines classification scheme#Classification of Recommendations|Class III]] (No Benefit)
|-
| bgcolor="LightCoral"|<nowiki>"</nowiki>'''1.''' [[ICD therapy]] is not indicated for patients who do not have a reasonable expectation of survival with an acceptable functional status for at least 1 year, even if they meet [[ICD implantation]] criteria specified in the Class I, IIa, and IIb recommendations above. ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: C]])''<nowiki>"</nowiki>
|-
| bgcolor="LightCoral"|<nowiki>"</nowiki>'''2.''' [[ICD therapy]] is not indicated for patients with incessant [[VT]] or [[ventricular fibrillation]]. ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: C]])''<nowiki>"</nowiki>
|-
| bgcolor="LightCoral"|<nowiki>"</nowiki>'''3.''' [[ICD therapy]] is not indicated in patients with significant [[psychiatric illness]]es that may be aggravated by device implantation or that may preclude systematic follow-up. ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: C]])''<nowiki>"</nowiki>
|-
| bgcolor="LightCoral"|<nowiki>"</nowiki>'''4.''' [[ICD therapy]] is not indicated for NYHA Class IV patients with [[drug-refractory congestive heart failure]] who are not candidates for [[cardiac transplantation]] or [[CRT-D]]. ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: C]])''<nowiki>"</nowiki>
|-
| bgcolor="LightCoral"|<nowiki>"</nowiki>'''5.''' [[ICD therapy]] is not indicated for [[syncope]] of undetermined cause in a patient without [[inducible ventricular tachyarrhythmias]] and without structural [[heart disease]]. ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: C]])''<nowiki>"</nowiki>
|-
| bgcolor="LightCoral"|<nowiki>"</nowiki>'''6.''' [[ICD therapy]] is not indicated when [[VF]] or [[VT]] is amenable to surgical or catheter ablation (e.g., [[atrial arrhythmias]] associated with the [[Wolff-Parkinson-White syndrome]], [[RV]] or [[LV]] [[outflow tract VT]], [[idiopathic VT]], or [[fascicular VT]] in the absence of structural [[heart disease]]). ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: C]])''<nowiki>"</nowiki>
|-
| bgcolor="LightCoral"|<nowiki>"</nowiki>'''7.''' [[ICD therapy]] is not indicated for patients with [[ventricular tachyarrhythmias]] due to a completely reversible disorder in the absence of structural [[heart disease]] (e.g., [[electrolyte imbalance]], [[drugs]], or [[trauma]]). ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: B]])''<nowiki>"</nowiki>
|}
{|class="wikitable"
|-
| colspan="1" style="text-align:center; background:LemonChiffon"|[[ACC AHA guidelines classification scheme#Classification of Recommendations|Class IIa]]
|-
| bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''1.''' [[ICD implantation]] is reasonable for patients with unexplained [[syncope]], significant [[LV dysfunction]], and [[nonischemic DCM]]. ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: C]])''<nowiki>"</nowiki>
|-
| bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''2.''' [[ICD implantation]] is reasonable for patients with [[sustained VT]] and normal or near-normal [[ventricular function]]. ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: C]])''<nowiki>"</nowiki>
|-
| bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''3.''' [[ICD implantation]] is reasonable for patients with [[HCM]] who have 1 or more major{dagger} risk factors for [[SCD]]. ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: C]])''<nowiki>"</nowiki>
|-
| bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''4.''' [[ICD implantation]] is reasonable for the prevention of [[SCD]] in patients with [[ARVD/C]] who have 1 or more risk factors for [[SCD]]. ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: C]])''<nowiki>"</nowiki>
|-
| bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''5.''' [[ICD implantation]] is reasonable to reduce [[SCD]] in patients with [[long-QT syndrome]] who are experiencing [[syncope]] and/or [[VT]] while receiving [[beta blockers]]. ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: B]])''<ref name="pmid12741701">{{cite journal| author=Zareba W, Moss AJ, Daubert JP, Hall WJ, Robinson JL, Andrews M| title=Implantable cardioverter defibrillator in high-risk long QT syndrome patients. | journal=J Cardiovasc Electrophysiol | year= 2003 | volume= 14 | issue= 4 | pages= 337-41 | pmid=12741701 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=12741701 }} </ref><ref name="pmid14521674">{{cite journal| author=Viskin S| title=Implantable cardioverter defibrillator in high-risk long QT syndrome patients. | journal=J Cardiovasc Electrophysiol | year= 2003 | volume= 14 | issue= 10 | pages= 1130-1; reply 1131 | pmid=14521674 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=14521674 }} </ref><ref name="pmid14994181">{{cite journal| author=Goel AK, Berger S, Pelech A, Dhala A| title=Implantable cardioverter defibrillator therapy in children with long QT syndrome. | journal=Pediatr Cardiol | year= 2004 | volume= 25 | issue= 4 | pages= 370-8 | pmid=14994181 | doi=10.1007/s00246-003-0566-4 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=14994181 }} </ref><ref name="pmid15840474">{{cite journal| author=Mönnig G, Köbe J, Löher A, Eckardt L, Wedekind H, Scheld HH et al.| title=Implantable cardioverter-defibrillator therapy in patients with congenital long-QT syndrome: a long-term follow-up. | journal=Heart Rhythm | year= 2005 | volume= 2 | issue= 5 | pages= 497-504 | pmid=15840474 | doi=10.1016/j.hrthm.2005.02.008 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=15840474 }} </ref><ref name="pmid16949500">{{cite journal| author=Goldenberg I, Mathew J, Moss AJ, McNitt S, Peterson DR, Zareba W et al.| title=Corrected QT variability in serial electrocardiograms in long QT syndrome: the importance of the maximum corrected QT for risk stratification. | journal=J Am Coll Cardiol | year= 2006 | volume= 48 | issue= 5 | pages= 1047-52 | pmid=16949500 | doi=10.1016/j.jacc.2006.06.033 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=16949500 }} </ref><ref name="pmid16968849">{{cite journal| author=Hobbs JB, Peterson DR, Moss AJ, McNitt S, Zareba W, Goldenberg I et al.| title=Risk of aborted cardiac arrest or sudden cardiac death during adolescence in the long-QT syndrome. | journal=JAMA | year= 2006 | volume= 296 | issue= 10 | pages= 1249-54 | pmid=16968849 | doi=10.1001/jama.296.10.1249 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=16968849 }} </ref><nowiki>"</nowiki>
|-
| bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''6.''' [[ICD implantation]] is reasonable for non hospitalized patients awaiting [[transplant]]ation. ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: C]])''<nowiki>"</nowiki>
|-
| bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''7.''' [[ICD implantation]] is reasonable for patients with [[Brugada syndrome]] who have had [[syncope]]. ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: C]])''<nowiki>"</nowiki>
|-
| bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''8.''' [[ICD implantation]] is reasonable for patients with [[Brugada syndrome]] who have documented [[VT]] that has not resulted in [[cardiac arrest]]. ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: C]])''<nowiki>"</nowiki>
|-
| bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''9.''' [[ICD implantation]] is reasonable for patients with [[catecholaminergic polymorphic VT]] who have syncope and/or documented sustained [[VT]] while receiving [[beta blockers]]. ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: C]])''<nowiki>"</nowiki>
|-
| bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''10.''' [[ICD implantation]] is reasonable for patients with [[cardiac sarcoidosis]], [[giant cell myocarditis]], or [[Chagas disease]]. ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: C]])''<nowiki>"</nowiki>
|}
{|class="wikitable"
|-
| colspan="1" style="text-align:center; background:LemonChiffon"|[[ACC AHA guidelines classification scheme#Classification of Recommendations|Class IIb]]
|-
| bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''1.''' [[ICD therapy]] may be considered in patients with nonischemic [[heart disease]] who have an [[LVEF]] of less than or equal to 35% and who are in NYHA functional Class I. ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: C]])''<nowiki>"</nowiki>
|-
| bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''2.''' [[ICD therapy]] may be considered for patients with [[long-QT syndrome]] and risk factors for [[SCD]]. ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: B]])''<nowiki>"</nowiki>
|-
| bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''3.''' [[ICD therapy]] may be considered in patients with [[syncope]] and advanced structural heart disease in whom thorough invasive and noninvasive investigations have failed to define a cause. ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: C]])''<nowiki>"</nowiki>
|-
| bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''4.''' [[ICD therapy]] may be considered in patients with a [[familial cardiomyopathy]] associated with sudden death. ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: C]])''<nowiki>"</nowiki>
|-
| bgcolor="LemonChiffon"|<nowiki>"</nowiki>'''5.''' [[ICD therapy]] may be considered in patients with [[LV]] noncompaction. ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: C]])''<nowiki>"</nowiki>
|}
===Implantable Cardioverter-Defibrillators in Pediatric Patients and Patients With Congenital Heart Disease<ref name="pmid18483207">{{cite journal |author=Epstein AE, DiMarco JP, Ellenbogen KA, ''et al'' |title=ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the ACC/AHA/NASPE 2002 Guideline Update for Implantation of Cardiac Pacemakers and Antiarrhythmia Devices): developed in collaboration with the American Association for Thoracic Surgery and Society of Thoracic Surgeons |journal=Circulation |volume=117 |issue=21 |pages=e350-408 |year=2008 |month=May |pmid=18483207 |doi:10.1161/CIRCUALTIONAHA.108.189742 |url=}}</ref>===
{|class="wikitable"
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| colspan="1" style="text-align:center; background:LightGreen"|[[ACC AHA guidelines classification scheme#Classification of Recommendations|Class I]]
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| bgcolor="LightGreen"|<nowiki>"</nowiki>'''1.''' [[ICD implantation]] is indicated in the survivor of [[cardiac arrest]] after evaluation to define the cause of the event and to exclude any reversible causes. ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: B]])''<nowiki>"</nowiki>
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| bgcolor="LightGreen"|<nowiki>"</nowiki>'''2.''' [[ICD implantation]] is indicated for patients with [[symptomatic sustained VT]] in association with [[congenital heart disease]] who have undergone hemodynamic and electrophysiological evaluation. [[Catheter ablation]] or surgical repair may offer possible alternatives in carefully selected patients. ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: C]])''<nowiki>"</nowiki>
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{|class="wikitable"
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| colspan="1" style="text-align:center; background:LightCoral"|[[ACC AHA guidelines classification scheme#Classification of Recommendations|Class III]] (No Benefit)
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| bgcolor="LightCoral"|
<nowiki>"</nowiki>'''1.''' All Class III recommendations found in Section 3, "Indications for Implantable Cardioverter-Defibrillator Therapy," apply to pediatric patients and patients with [[congenital heart disease]], and [[ICD implantation]] is not indicated in these patient populations. ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: C]])''<nowiki>"</nowiki>
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{|class="wikitable"
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| colspan="1" style="text-align:center; background:LemonChiffon"|[[ACC AHA guidelines classification scheme#Classification of Recommendations|Class IIa]]
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| bgcolor="LemonChiffon"|
<nowiki>"</nowiki>'''1.''' [[ICD implantation]] is reasonable for patients with [[congenital heart disease]] with [[recurrent syncope]] of undetermined origin in the presence of either [[ventricular dysfunction]] or [[inducible ventricular arrhythmia]]s at electrophysiological study. ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: B]])''<nowiki>"</nowiki>
|}
{|class="wikitable"
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| colspan="1" style="text-align:center; background:LemonChiffon"|[[ACC AHA guidelines classification scheme#Classification of Recommendations|Class IIb]]
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| bgcolor="LemonChiffon"|
<nowiki>"</nowiki>'''1.''' [[ICD implantation]] may be considered for patients with [[recurrent syncope]] associated with complex [[congenital heart disease]] and [[advanced systemic ventricular dysfunction]] when thorough invasive and noninvasive investigations have failed to define a cause. ''([[ACC AHA guidelines classification scheme#Level of Evidence|Level of Evidence: C]])''<nowiki>"</nowiki>
Expert Consensus on the Use of Implantable Cardioverter-Defibrillator Therapy in Patients Who Are Not Included or Not Well Represented in Clinical Trials
The process of implantation of an ICD is similar to implantation of a pacemaker. Similar to pacemakers, these devices typically include electrode wire(s) which pass through a vein to the right chambers of the heart, usually being lodged in the apex of the right ventricle. The difference is that pacemakers are more often temporary and generally designed to consistently correct bradycardia, while ICDs are often permanent safeguards against sudden abnormalities.
The most recent development is the subcutaneous ICD (S-ICD). Current state-of-the-art electronics and batteries have enabled an implantable device to deliver enough energy to defibrillate the heart without the need for a lead in or on the heart. This prevents lead-related problems and the risk of dangerous infections in or near the heart. This ICD is positioned just under the skin and outside the ribcage. It can be placed during a minor procedure under conscious sedation. A study of 300 patients is in progress for US approvals.[1]
Working mechanism
ICDs constantly monitor the rate and rhythm of the heart and can deliver therapies, by way of an electrical shock, when the electrical manifestations of the heart activity exceeds the preset number. More modern devices can distinguish between ventricular fibrillation and ventricular tachycardia (VT), and may try to pace the heart faster than its intrinsic rate in the case of VT, to try to break the tachycardia before it progresses to ventricular fibrillation. This is known as fast-pacing, overdrive pacing, or anti-tachycardia pacing (ATP). ATP is only effective if the underlying rhythm is ventricular tachycardia, and is never effective if the rhythm is ventricular fibrillation.
Many modern ICDs use a combination of various methods to determine if a fast rhythm is normal, ventricular tachycardia, or ventricular fibrillation.
Rate discrimination evaluates the rate of the lower chambers of the heart (the ventricles) and compares it to the rate in the upper chambers of the heart (the atria). If the rate in the atria is faster than or equal to the rate in the ventricles, then the rhythm is most likely not ventricular in origin, and is usually more benign. If this is the case, the ICD does not provide any therapy.
Rhythm discrimination will see how regular a ventricular tachycardia is. Generally, ventricular tachycardia is regular. If the rhythm is irregular, it is usually due to conduction of an irregular rhythm that originates in the atria, such as atrial fibrillation.
Morphology discrimination checks the morphology of every ventricular beat and compares it to what the ICD believes is a normally conducted ventricular impulse for the patient. This normal ventricular impulse is often an average of a multiple of beats of the patient taken in the recent past.
The development of the ICD was pioneered at Sinai Hospital in Baltimore by a team including Michel Mirowski, Morton Mower, and William Staewen.[2] Mirowski teamed up with Mower and Staewen and together they commenced their research in 1969 but it was 11 years before they treated their first patient. Similar developmental work was carried out almost coincidentally by Schuder and colleagues at the University of Missouri.
More than a decade of research went into the development of an implantable defibrillator that would automatically sense the onset of ventricular fibrillation and deliver an electric countershock within 15–20 seconds, converting the rhythm to sinus rhythm. Improved versions were programmed to be able to detect ventricular tachycardia, often a forerunner of ventricular fibrillation. These were then called implantable cardioverters.
The work was commenced against much skepticism even by leading experts in the field of arrhythmias and sudden death. There was doubt that their ideas would ever become a clinical reality. In 1972 Bernard Lown, the inventor of the external defibrillator, stated in the journal Circulation - "The very rare patient who has frequent bouts of ventricular fibrillation is best treated in a coronary care unit and is better served by an effective antiarrhythmic program or surgical correction of inadequate coronary blood flow or ventricular malfunction. In fact, the implanted defibrillator system represents an imperfect solution in search of a plausible and practical application".
The problems to be overcome were the design of a system which would allow detection of ventricular fibrillation or ventricular tachycardia. Despite the lack of financial backing and grants, they persisted and the first device was implanted in February 1980 at Johns Hopkins Hospital by Dr. Levi Watkins, Jr. Modern ICDs do not require a thoracotomy and possess pacing, cardioversion, and defibrillation capabilities.
Internal cardioverter defibrillators have also been used twice in dogs to prevent sudden death from arrhythmia. The first defibrillator was implanted at Washington State University by a team of cardiologists led by Dr Lynne Johnson in 2003. The patient was a Boxer dog with life threatening arrhythmias from arrhythmogenic right ventricular cardiomyopathy, an inherited disease. On July 21, 2008, a second ICD was implanted in a 6-month-old German Shepherd dog with inherited ventricular arrhythmias. The 5-hour long surgery took place at Louisiana State University and was led by Dr Romain Pariaut. So far, these pets are the only two client-owned dogs that have received such a high-tech treatment.
Note: Duration of antimicrobial therapy should be at least 4 to 6 weeks for complicated infection (ie, endocarditis, septic thrombophlebitis, or osteomyelitis or if bloodstream infection persists despite device removal and appropriate initial antimicrobial therapy.
People that have an implanted cardioverter-defibrillator can live full and happy lives. Usually the ICD improves the living conditions of a patient significantly. As with a pacemaker, living with an ICD does impose some restrictions on the person's lifestyle.
Quality of Life
Implantable cardioverter defibrillators have demonstrated clear life-saving benefits but concerns about patient acceptance and psychological adjustment to the ICD have been the focus of much research.[8] Researchers including those from the field of cardiac psychology have concluded that the QoL of ICD patients is at least equal to, or better than those taking anti-arrhythmic medications.[9] The largest study of examined 2,521 patients with stable heart failure in the SCD-HeFT trial.[10] Results indicated that there were no differences between ICD treated and medication-treated groups at 30 months in patient reported QoL.[11] Psychological adjustment following ICD implantation has also been well-studied. Anxiety is a common psychological side effect with approximately 13-38% of ICD patients reporting clinically significant anxiety.[12][13] The primary etiological factors contributing to anxiety in ICD patients has not been determined, however. Depressive symptoms are also common but incidence of these problems have shown to be similar to those observed in other cardiac patient groups with approximately 24-41% of patients with ICDs experiencing depressive symptoms.[13]
Problems in psychosocial adjustment to ICDs, including the experience of anxiety, among spouses or other romantic partners are also prevalent[14]. This phenomenon may be related, at least in part, to shared shock anxiety and avoidance of physical and sexual contact [15].
Physical activities
Almost all forms of physical activities can be performed by patients with an ICD. All forms of sports that do not pose a risk of damaging the ICD can be enjoyed by the patient. Special care should be placed not to put excessive strain on the shoulder, arm and torso area where the ICD is implanted. Doing so may damage the ICD or the leads going from the unit to the patient's heart.
Electronic equipment
As a general rule, all electronic equipment is safe to use for patients with an ICD if kept at relative small distance from the unit. Most electronic equipment such as cellphones, Devices that generate radio waves or radio interference should be kept at least 15 centimetres (6 in) from the ICD.[16]
Electronic equipment used in a professional environment or equipment using large magnets or generating magnetic fields must be avoided by patients with an ICD. Both the magnetic fields and the EMI (Electromagnetic Interference) in an MRI scanner can interfere with the correct working of the ICD.
As with other metallic objects, an ICD is a contraindication to the use of magnetic resonance imaging. Experiments are on the way for solving this kind of problem. For example Medtronic showed interesting results with a pacemaker.[17]
Clinical trials
A number of clinical trials have demonstrated the superiority of the ICD over AAD (antiarrhythmic drugs) in the prevention of death from malignant arrhythmias.
The SCD-HeFT trial (published in 2005) showed a significant all-cause mortality benefit for patients with ICD. Congestive heart failure patients that were implanted with an ICD had an all-cause death risk 23% lower than placebo and an absolute decrease in mortality of 7.2 percentage points after five years in the overall population.1
Reporting in 1999, the Antiarrhythmics Versus Implantable Defibrillators (AVID) trial consisted of 1,016 patients, and deaths in those treated with AAD were more frequent (n=122) compared with deaths in the ICD groups (n=80, p < 0.001)[4]. In 2002 the MADITII trial showed benefit of ICD treatment in patients after myocardial infarction with reduced left ventricular function (EF<30).
Initially ICDs were implanted via thoracotomy with defibrillator patches applied to the epicardium or pericardium. The device was attached via subcutaneous and transvenous leads to the device contained in a subcutaneous abdominal wall pocket. The device itself acts as an electrode. Most ICDs nowadays are implanted transvenously with the devices placed in the left pectoral region similar to pacemakers. Intravascular spring or coil electrodes are used to defibrillate. The devices have become smaller and less invasive as the technology advances. Current ICDs weigh only 70 grams and are about 12.9 mm thick.
A recent study by Birnie et al. at the University of Ottawa Heart Institute has demonstrated that ICDs are underused in both the United States and Canada.[18] An accompanying editorial by Dr. Chris Simpson of Queen's University explores some of the economic, geographic, social and political reasons for this.[19]
Sources
ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the ACC/AHA/NASPE 2002 Guideline Update for Implantation of Cardiac Pacemakers and Antiarrhythmia Devices): developed in collaboration with the American Association for Thoracic Surgery and Society of Thoracic Surgeons [20]
ACC/AHA/NASPE 2002 guideline update for implantation of cardiac pacemakers and antiarrhythmia devices: summary article: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (ACC/AHA/NASPE Committee to Update the 1998 Pacemaker Guidelines) [21]
ACC/AHA Guidelines for Implantation of Cardiac Pacemakers and Antiarrhythmia Devices: Executive Summary--a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Pacemaker Implantation) [22]
↑Mirowski M, Mower MM, Staewen WS, et al: Standby automatic defibrillator: An approach to prevention of sudden coronary death. Arch Intern Med 126:158-161, 1970
↑Baddour, L. M.; Epstein, A. E.; Erickson, C. C.; Knight, B. P.; Levison, M. E.; Lockhart, P. B.; Masoudi, F. A.; Okum, E. J.; Wilson, W. R.; Beerman, L. B.; Bolger, A. F.; Estes, N. A. M.; Gewitz, M.; Newburger, J. W.; Schron, E. B.; Taubert, K. A. (2010). "Update on Cardiovascular Implantable Electronic Device Infections and Their Management: A Scientific Statement From the American Heart Association". Circulation. 121 (3): 458–477. doi:10.1161/CIRCULATIONAHA.109.192665. ISSN0009-7322.
↑ 7.07.1Sohail, Muhammad R.; Uslan, Daniel Z.; Khan, Akbar H.; Friedman, Paul A.; Hayes, David L.; Wilson, Walter R.; Steckelberg, James M.; Stoner, Sarah; Baddour, Larry M. (2007). "Management and Outcome of Permanent Pacemaker and Implantable Cardioverter-Defibrillator Infections". Journal of the American College of Cardiology. 49 (18): 1851–1859. doi:10.1016/j.jacc.2007.01.072. ISSN0735-1097.
↑Burns JL, Serber ER, Keim S, Sears SF. Measuring patient acceptance of implantable cardiac device therapy: initial psychometric investigation of the Florida Patient Acceptance Survey. J Cardiovasc Electrophysiol 2005;16:384-390.
↑Sears S, Matchett M, Conti J. Effective management of ICD patient psychosocial issues and patient critical events. J Cardiovasc Electrophysiol 2009;20(11):1297-304
↑Mark DB, Anstrom KJ, Sun JL, Clapp-Channing NE, Tsiatis AA, Davidson-Ray L, Lee KL, Bardy GH. Quality of life with defibrillator therapy or amiodarone in heart failure. N Engl J Med 2008; 359(10):999-1008
↑Bilge AK, Ozben B, Demircan S, et al. Depression and anxiety status of patients with implantable cardioverter defibrillator and precipitating factors. Pacing Clin Electrophysiol. 2006 Jun;29(6):619-26
↑ 13.013.1Sears SF, Jr., Todaro JF, Lewis TS, Sotile W, Conti JB. Examining the psychosocial impact of implantable cardioverter defibrillators: a literature review. Clin Cardiol 1999;22:481-489
↑Vasquez-Sowell L, Sears SF, Walker RL, Kuhl EA, Conti JB. Anxiety and marital adjustment in patients with Implantable Cardioverter Defibrillator and their spouses. Journal of Cardiopulmonary Rehabilitation and Prevention 2007;27:46-49
↑Vasquez LD, Sears SF, Shea JB, Vasquez PM. Sexual health for patients with an Implantable Cardioverter Defibrillator. Circulation 2010;122:465-467
↑Medtronic Patient Website FAQ: Can magnets affect my device? [1]
↑Epstein AE, DiMarco JP, Ellenbogen KA; et al. (2008). "ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the ACC/AHA/NASPE 2002 Guideline Update for Implantation of Cardiac Pacemakers and Antiarrhythmia Devices): developed in collaboration with the American Association for Thoracic Surgery and Society of Thoracic Surgeons". Circulation. 117 (21): e350–408. PMID18483207. Text "doi:10.1161/CIRCUALTIONAHA.108.189742 " ignored (help); Unknown parameter |month= ignored (help)CS1 maint: Explicit use of et al. (link) CS1 maint: Multiple names: authors list (link)
↑Gregoratos G, Abrams J, Epstein AE; et al. (2002). "ACC/AHA/NASPE 2002 guideline update for implantation of cardiac pacemakers and antiarrhythmia devices: summary article: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (ACC/AHA/NASPE Committee to Update the 1998 Pacemaker Guidelines)". Circulation. 106 (16): 2145–61. PMID12379588. Text "doi:10.1161/01.CIR.0000035996.46455.09 " ignored (help); Unknown parameter |month= ignored (help)CS1 maint: Explicit use of et al. (link) CS1 maint: Multiple names: authors list (link)
↑Gregoratos G, Cheitlin MD, Conill A; et al. (1998). "ACC/AHA Guidelines for Implantation of Cardiac Pacemakers and Antiarrhythmia Devices: Executive Summary--a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Pacemaker Implantation)". Circulation. 97 (13): 1325–35. PMID9570207. Unknown parameter |month= ignored (help)CS1 maint: Explicit use of et al. (link) CS1 maint: Multiple names: authors list (link)
