Ventricular escape beat: Difference between revisions

Jump to navigation Jump to search
VisualWikitext
WikiBot (talk | contribs)
Bots, Bureaucrats, bureaucrats, interwiki, nocaptcha, Administrators
57,550 edits
m Robot: Automated text replacement (-{{SIB}} +, -{{EH}} +, -{{EJ}} +, -{{Editor Help}} +, -{{Editor Join}} +)
 
Kiran Singh (talk | contribs)
nocaptcha, Administrators
24,170 edits
 
(27 intermediate revisions by 6 users not shown)
Line 1: Line 1:
__NOTOC__
{{SI}}
{{SI}}
{{WikiDoc Cardiology Network Infobox}}
{{CMG}}


{{CMG}}; {{AE}} {{M.P}}


{{SK}} Ventricular escape; ventricular escape beats; ventricular escape beat, ventricular escape rhythm


A '''ventricular escape beat''' is a heart rhythm finding, discovered on [[EKG]], that indicates the normal [[electrical conduction system of the heart]] is disrupted or performing inadequately.   
==Overview==
A ventricular escape beat is a self-generated electrical discharge initiated by and causing contraction of the [[ventricles]] of the [[heart]].  It is a heart rhythm finding discovered on [[EKG]], that indicates the normal [[electrical conduction system of the heart]] is disrupted or performing inadequately i.e failure of the [[SA node]] and [[AV node]] to generate an impulse.  The ventricular escape beat follows a long pause in ventricular rhythm and acts to prevent [[cardiac arrest]].


More specifically, it is an [[Cardiac ectopy|ectopic]] beat that occurs after an extended pause in a rhythm, indicating either the failure of the [[SA node]] to initiate a beat or the failure of the conduction of this beat to the [[AV node]].  While the SA node typically initiates a rate of 70 beats per minute (BPM), the AV node is usually only capable of generating a rhythm at 40-60 BPM.  If the AV node does not receive a signal from the SA node after a second or two, the AV node's pacemaking activity kicks in (as a safety mechanism), and attempts to set the rate around 40 BPM.
==Pathophysiology==
* Ventricular escape beats occur when the rate of electrical discharge reaching the ventricles (normally initiated by the heart's [[sinoatrial node]], transmitted to the [[atrioventricular node]], and then further transmitted to the ventricles) falls below the base rate determined by the ventricular pacemaker cells.<ref>C. Andreasen, et al. (2006) Mosby Elsevier, Mosby's Dictionary of Medicine, Nursing and Health Professions 7th edition, p1951</ref>


If there are only one or two [[Cardiac ectopy|ectopic]] beats, they are considered escape beats.  If this causes a semi-normal rhythm to arise it is considered an [[idioventricular rhythm]].
*Normally, the pacemaker cells of the sinoatrial node discharge at the highest frequency (70 beats per minute) and are thus dominant over other cells with pacemaker activity.  The AV node normally has the second fastest discharge rate (40-60 beats per minute).  If the rate from both the SA and AV node fall below the discharge rate of ventricular pacemaker cells, a ventricular escape beat ensues (less than 40 beats per minute).


The escape [[arrhythmia]] is a compensatory mechanism that indicates a serious underlying problem with the SA node or conduction system (commonly due to [[myocardial infarction|heart attack]] or medication [[Adverse effect (medicine)|side effect]]) , and because of its low rate, it can cause a drop in [[blood pressure]].
* An escape beat usually occurs 2–3 seconds after an electrical impulse has failed to reach the ventricles. <ref name="pmid1122512">{{cite journal |author=Banka VS, Scherlag BJ, Helfant RH |title=Contractile and electrophysiological responses to progressive digitalis toxicity |journal=Cardiovasc. Res. |volume=9 |issue=1 |pages=65–72 |year=1975 |month=January |pmid=1122512 |doi= 10.1093/cvr/9.1.65|url=http://cardiovascres.oxfordjournals.org/cgi/pmidlookup?view=long&pmid=1122512}}</ref>


An escape rhythm may develop if another pacemaker takes over.
==Causes==
===Life Threatening Causes===
Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated.
*[[Acute coronary syndrome]]
*[[carbamate|Carbamate poisoning]]
*[[Diabetic ketoacidosis]]
*[[NSTEMI]]
*[[organophosphate|Organophosphate poisoning]]
*[[parathion|Parathion poisoning]]
*[[brain damage|Severe brain injury]]


{{Electrocardiography}}
===Common Causes===
{{Circulatory system pathology}}
*[[Acetylcholine]]
*[[Acute coronary syndrome]]
*[[Acute rheumatic fever]]
*[[Amiodarone]]
*[[Beta-blockers]]
*[[Calcium channel blockers]]
*[[Cardiac catheterization]]
*[[Congestive heart failure]]
*[[Dilated cardiomyopathy]]
*[[Hyperkalemia]]
*[[Hypermagnesemia]]
*[[Hypertensive heart disease]]
*[[Myocarditis]]
*[[Renal failure]]


===Causes by Organ System===
{|style="width:80%; height:100px" border="1"
|style="height:100px"; style="width:25%" border="1" bgcolor="LightSteelBlue" |'''Cardiovascular'''
|style="height:100px"; style="width:75%" border="1" bgcolor="Beige" | [[Acute coronary syndrome]], [[acute rheumatic fever]], [[Andersen cardiodysrhythmic periodic paralysis]], [[Brugada syndrome]], [[cardiac tumor]], [[complete heart block]], [[congenital heart disease]], [[congestive heart failure]], [[dilated cardiomyopathy]], [[hypertensive heart disease]], [[hypertrophic cardiomyopathy]], [[ischemic heart disease]], [[Jervell and Lange-Nielsen syndrome]], [[Lev's disease]], [[long QT syndrome]], [[myocardial bridging]], [[myocardial infarction]], [[myocarditis]], [[NSTEMI]], [[pericarditis]], [[Romano-Ward syndrome]], [[STEMI]], [[Timothy syndrome]], [[valvular heart disease]]
|-
|bgcolor="LightSteelBlue"| '''Chemical/Poisoning'''
|bgcolor="Beige"| [[carbamate|Carbamate poisoning]], [[organophosphate|organophosphate poisoning]], [[parathion|parathion poisoning]]
|-
|-bgcolor="LightSteelBlue"
| '''Dental'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Dermatologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Drug Side Effect'''
|bgcolor="Beige"| [[Acetylcholine]], [[amiodarone]], [[anthracyclines]], [[beta-blockers]], [[calcium channel blockers]], [[cholinesterase inhibitors]], [[daunorubicin]], [[digitalis]], [[doxorubicin]], [[edrophonium]], [[epirubicin]], [[idarubicin]], [[neostigmine]], [[procainamide]], [[propafenone]], [[propofol]], [[pyridostigmine]], [[quinidine]], [[tramadol]]
|-
|-bgcolor="LightSteelBlue"
| '''Ear Nose Throat'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Endocrine'''
|bgcolor="Beige"| [[Diabetic ketoacidosis]], [[hyperthyroidism]], [[hypothyroidism|profound hypothyroidism]]
|-
|-bgcolor="LightSteelBlue"
| '''Environmental'''
|bgcolor="Beige"| [[Hypothermia]]
|-
|-bgcolor="LightSteelBlue"
| '''Gastroenterologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Genetic'''
|bgcolor="Beige"| [[Andersen cardiodysrhythmic periodic paralysis]], [[Brugada syndrome]], [[congenital heart block]], [[congenital heart disease]], [[Emery-Dreifuss muscular dystrophy]], [[Jervell and Lange-Nielsen syndrome]], [[Kearns-Sayre syndrome]], [[Limb-girdle muscular dystrophy|limb-girdle muscular dystrophy type 1B (LGMD1B)]], [[muscular dystrophy]], [[myotonic dystrophy]], [[Romano-Ward syndrome]], [[Timothy syndrome]]
|-
|-bgcolor="LightSteelBlue"
| '''Hematologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Iatrogenic'''
|bgcolor="Beige"| [[Cardiac catheterization]], [[cardiac resynchronization therapy]], [[cardiac transplantation]], [[coronary artery bypass grafting]], [[heart surgery]], [[hypertrophic cardiomyopathy alcohol septal ablation]], [[regional anesthesia|infraclavicular brachial plexus block]]
|-
|-bgcolor="LightSteelBlue"
| '''Infectious Disease'''
|bgcolor="Beige"| [[Acute rheumatic fever]], [[myocarditis]], [[pericarditis]], [[septic shock]]
|-
|-bgcolor="LightSteelBlue"
| '''Musculoskeletal/Orthopedic'''
|bgcolor="Beige"| [[Muscular dystrophy]], [[myotonic dystrophy]], [[Timothy syndrome]]
|-
|-bgcolor="LightSteelBlue"
| '''Neurologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Nutritional/Metabolic'''
|bgcolor="Beige"| [[Hypermagnesemia]], [[hypocalcemia]], [[metabolic acidosis]]
|-
|-bgcolor="LightSteelBlue"
| '''Obstetric/Gynecologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Oncologic'''
|bgcolor="Beige"| [[Cardiac tumor]]
|-
|-bgcolor="LightSteelBlue"
| '''Ophthalmologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Overdose/Toxicity'''
|bgcolor="Beige"| [[Acetylcholine]], [[amiodarone]], [[anthracyclines]], [[cholinesterase inhibitors]], [[propofol]], [[quinidine]], [[tramadol]]
|-
|-bgcolor="LightSteelBlue"
| '''Psychiatric'''
|bgcolor="Beige"| [[Takotsubo cardiomyopathy]], [[anorexia nervosa|severe anorexia nervosa]]
|-
|-bgcolor="LightSteelBlue"
| '''Pulmonary'''
|bgcolor="Beige"| [[Hypoxia]]
|-
|-bgcolor="LightSteelBlue"
| '''Renal/Electrolyte'''
|bgcolor="Beige"| [[Hyperkalemia]], [[renal failure]]
|-
|-bgcolor="LightSteelBlue"
| '''Rheumatology/Immunology/Allergy'''
|bgcolor="Beige"| [[Acute rheumatic fever]], [[neonatal lupus erythematosus]]
|-
|-bgcolor="LightSteelBlue"
| '''Sexual'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Trauma'''
|bgcolor="Beige"| [[Myocardial contusion]], [[brain damage|severe brain injury]]
|-
|-bgcolor="LightSteelBlue"
| '''Urologic'''
|bgcolor="Beige"| No underlying causes
|-
|-bgcolor="LightSteelBlue"
| '''Miscellaneous'''
|bgcolor="Beige"| No underlying causes
|-
|}


===Causes in Alphabetical Order===
{{col-begin|width=80%}}
{{col-break|width=33%}}
*[[Acetylcholine]]
*[[Acute coronary syndrome]]
*[[Acute rheumatic fever]]
*[[Amiodarone]]
*[[Andersen cardiodysrhythmic periodic paralysis]]
*[[Anthracyclines]]
*[[Beta-blockers]]
*[[Brugada syndrome]]
*[[Calcium channel blockers]]
*[[carbamate|Carbamate poisoning]]
*[[Cardiac catheterization]]
*[[Cardiac resynchronization therapy]]
*[[Cardiac transplantation]]
*[[Cardiac tumor]]
*[[Cholinesterase inhibitors]]
*[[Complete heart block]]
*[[Congenital heart disease]]
*[[Congestive heart failure]]
*[[Coronary artery bypass grafting]]
*[[Daunorubicin]]
*[[Diabetic ketoacidosis]]
*[[Digitalis]]
*[[Dilated cardiomyopathy]]
*[[Doxorubicin]]
{{col-break|width=33%}}
*[[Edrophonium]]
*[[Emery-Dreifuss muscular dystrophy]]
*[[Epirubicin]]
*[[Heart surgery]]
*[[Hyperkalemia]]
*[[Hypermagnesemia]]
*[[Hypertensive heart disease]]
*[[Hyperthyroidism]]
*[[Hypertrophic cardiomyopathy]]
*[[Hypertrophic cardiomyopathy alcohol septal ablation]]
*[[Hypocalcemia]]
*[[Hypothermia]]
*[[Hypoxia]]
*[[Idarubicin]]
*[[regional anesthesia|Infraclavicular brachial plexus block]]
*[[Ischemic heart disease]]
*[[Jervell and Lange-Nielsen syndrome]]
*[[Kearns-Sayre syndrome]]
*[[Lev's disease]]
*[[Limb-girdle muscular dystrophy|Limb-girdle muscular dystrophy type 1B (LGMD1B)]]
*[[Long QT syndrome]]
*[[Muscular dystrophy]]
*[[Myocardial bridging]]
*[[Myocardial contusion]]
{{col-break|width=33%}}
*[[Myocardial infarction]]
*[[Myocarditis]]
*[[Myotonic dystrophy]]
*[[Neonatal lupus erythematosus]]
*[[Neostigmine]]
*[[organophosphate|Organophosphate poisoning]]
*[[parathion|Parathion poisoning]]
*[[Pericarditis]]
*[[Procainamide]]
*[[hypothyroidism|Profound hypothyroidism]]
*[[Propafenone]]
*[[Propofol]]
*[[Pyridostigmine]]
*[[Quinidine]]
*[[Renal failure]]
*[[Romano-Ward syndrome]]
*[[anorexia nervosa|Severe anorexia nervosa]]
*[[brain damage|Severe brain injury]]
*[[Takotsubo cardiomyopathy]]
*[[Timothy syndrome]]
*[[Tramadol]]
*[[Valvular heart disease]]
{{col-end}}
==Differentiating Ventricular Escape Beat from other Diseases==
*[[Junctional escape beat]] : When the sinus rate falls below the discharge rate of the AV node, this becomes the dominant pacemaker, and the result is called a [[junctional escape beat]].  The AV node usually generates a rhythm at 40-60 BPM.
*[[Idioventricular rhythm]] : An escape beat is a form of cardiac [[arrhythmia]], in this case known as an [[cardiac ectopy|ectopic beat]].  If there are only one or two ectopic beats, they are considered escape beats.  If this causes a semi-normal rhythm to arise it is considered an [[idioventricular rhythm]].
*[[Premature ventricular contraction]] : An absence of P wave activity, associated with a widened QRS complex resembles a PVC, but occuring after a pause of variable duration differentiate ventricular escape beat from [[PVCs]].
*[[Complete heart block]] : In complete or third degree heart block there is sinus node activity but failure of conduction through the AV node.  There are P waves dissociated from the ventricular complexes with a rate faster than the ventricular rate that differentiates complete heart block from ventricular escape beat where there is absence of P waves.
==Diagnosis==
===History and Symptoms===
The escape [[arrhythmia]] is a compensatory mechanism that indicates a serious underlying problem with the SA node or conduction system (commonly due to [[myocardial infarction|heart attack]] or medication [[Adverse effect (medicine)|side effect]]), and because of its low rate, it can cause a drop in [[blood pressure]].  Some of the symptoms related to hypotension are:
*[[Dizziness]]
*[[Fatigue]]
*[[Presyncope]]
*[[Syncope]]
===Physcial Examination===
* [[Bradycardia]] may be present.  The rate is below 40 beats per minute.
* [[Tachypnea]] may be present.
* Elevated [[JVP]] may be seen if heart failure is present.
* [[S3]] gallop may be heard in the presence of heart failure.
===Laboratory Findings===
The following laboratory studies should be done, depending upon the cause, while investigating a case of ventricular escape beat.
* [[Complete blood count]]
* Differential count
* Serum electrolytes - [[hyperkalemia]] ([[renal insufficiency]])
* Blood [[digoxin]] levels should be measured in case of [[digoxin overdose]]
* Myocarditis related studies - [[HIV]] serologies, [[Lyme]] titers, [[Chagas]] titers, [[enterovirus]] PCR, [[adenovirus]] [[PCR]]
===Electrocardiogram===
An [[electrocardiogram]] can be used to identify a ventricular escape beat.  The [[QRS]] portion of the [[electrocardiogram]] represents the ventricular [[depolarization]]; in normal circumstances the QRS complex forms a sharp sudden peak.  For a patient with a ventricular escape beat, the shape of the QRS complex is broader as the impulse can not travel quickly via the normal electrical conduction system.<ref name="pmid14503433">{{cite journal |author=Adams MG, Pelter MM |title=Ventricular escape rhythms |journal=Am. J. Crit. Care |volume=12 |issue=5 |pages=477–8 |year=2003 |month=September |pmid=14503433 |doi= |url=http://ajcc.aacnjournals.org/cgi/pmidlookup?view=long&pmid=14503433}}</ref>
==Factors Affecting Ventricular Escape Beat==
* [[Cilostazol]] has been used in patients with [[third degree AV block]] to increase ventricular escape rate.<ref name="pmid12684307">{{cite journal |author=Kodama-Takahashi K, Kurata A, Ohshima K, ''et al.'' |title=Effect of cilostazol on the ventricular escape rate and neurohumoral factors in patients with third-degree atrioventricular block |journal=Chest |volume=123 |issue=4 |pages=1161–9 |year=2003 |month=April |pmid=12684307 |doi= 10.1378/chest.123.4.1161|url=http://www.chestjournal.org/cgi/pmidlookup?view=long&pmid=12684307}}</ref>
*[[Ouabain]] infusion decreases ventricular escape time and increases ventricular escape rhythm.  However, a high dose of ouabain can lead to ventricular [[tachycardia]].<ref name="pmid1122512"/>
==References==
{{Reflist|2}}
[[Category:Crowdiagnosis]]
[[Category:Cardiology]]
[[Category:Cardiology]]
[[Category:Electrophysiology]]
[[Category:Arrhythmia]]
[[Category:Up-To-Date]]
[[Category:Up-To-Date cardiology]]
[[Category:Disease]]
{{WikiDoc Help Menu}}
{{WikiDoc Help Menu}}
{{WikiDoc Sources}}
{{WikiDoc Sources}}

Latest revision as of 16:38, 16 June 2015

WikiDoc Resources for Ventricular escape beat

Articles

Most recent articles on Ventricular escape beat

Most cited articles on Ventricular escape beat

Review articles on Ventricular escape beat

Articles on Ventricular escape beat in N Eng J Med, Lancet, BMJ

Media

Powerpoint slides on Ventricular escape beat

Images of Ventricular escape beat

Photos of Ventricular escape beat

Podcasts & MP3s on Ventricular escape beat

Videos on Ventricular escape beat

Evidence Based Medicine

Cochrane Collaboration on Ventricular escape beat

Bandolier on Ventricular escape beat

TRIP on Ventricular escape beat

Clinical Trials

Ongoing Trials on Ventricular escape beat at Clinical Trials.gov

Trial results on Ventricular escape beat

Clinical Trials on Ventricular escape beat at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on Ventricular escape beat

NICE Guidance on Ventricular escape beat

NHS PRODIGY Guidance

FDA on Ventricular escape beat

CDC on Ventricular escape beat

Books

Books on Ventricular escape beat

News

Ventricular escape beat in the news

Be alerted to news on Ventricular escape beat

News trends on Ventricular escape beat

Commentary

Blogs on Ventricular escape beat

Definitions

Definitions of Ventricular escape beat

Patient Resources / Community

Patient resources on Ventricular escape beat

Discussion groups on Ventricular escape beat

Patient Handouts on Ventricular escape beat

Directions to Hospitals Treating Ventricular escape beat

Risk calculators and risk factors for Ventricular escape beat

Healthcare Provider Resources

Symptoms of Ventricular escape beat

Causes & Risk Factors for Ventricular escape beat

Diagnostic studies for Ventricular escape beat

Treatment of Ventricular escape beat

Continuing Medical Education (CME)

CME Programs on Ventricular escape beat

International

Ventricular escape beat en Espanol

Ventricular escape beat en Francais

Business

Ventricular escape beat in the Marketplace

Patents on Ventricular escape beat

Experimental / Informatics

List of terms related to Ventricular escape beat

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Mugilan Poongkunran M.B.B.S [2]

Synonyms and keywords: Ventricular escape; ventricular escape beats; ventricular escape beat, ventricular escape rhythm

Overview

A ventricular escape beat is a self-generated electrical discharge initiated by and causing contraction of the ventricles of the heart. It is a heart rhythm finding discovered on EKG, that indicates the normal electrical conduction system of the heart is disrupted or performing inadequately i.e failure of the SA node and AV node to generate an impulse. The ventricular escape beat follows a long pause in ventricular rhythm and acts to prevent cardiac arrest.

Pathophysiology

  • Ventricular escape beats occur when the rate of electrical discharge reaching the ventricles (normally initiated by the heart's sinoatrial node, transmitted to the atrioventricular node, and then further transmitted to the ventricles) falls below the base rate determined by the ventricular pacemaker cells.[1]
  • Normally, the pacemaker cells of the sinoatrial node discharge at the highest frequency (70 beats per minute) and are thus dominant over other cells with pacemaker activity. The AV node normally has the second fastest discharge rate (40-60 beats per minute). If the rate from both the SA and AV node fall below the discharge rate of ventricular pacemaker cells, a ventricular escape beat ensues (less than 40 beats per minute).
  • An escape beat usually occurs 2–3 seconds after an electrical impulse has failed to reach the ventricles. [2]

Causes

Life Threatening Causes

Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated.

Common Causes

Causes by Organ System

Cardiovascular Acute coronary syndrome, acute rheumatic fever, Andersen cardiodysrhythmic periodic paralysis, Brugada syndrome, cardiac tumor, complete heart block, congenital heart disease, congestive heart failure, dilated cardiomyopathy, hypertensive heart disease, hypertrophic cardiomyopathy, ischemic heart disease, Jervell and Lange-Nielsen syndrome, Lev's disease, long QT syndrome, myocardial bridging, myocardial infarction, myocarditis, NSTEMI, pericarditis, Romano-Ward syndrome, STEMI, Timothy syndrome, valvular heart disease
Chemical/Poisoning Carbamate poisoning, organophosphate poisoning, parathion poisoning
Dental No underlying causes
Dermatologic No underlying causes
Drug Side Effect Acetylcholine, amiodarone, anthracyclines, beta-blockers, calcium channel blockers, cholinesterase inhibitors, daunorubicin, digitalis, doxorubicin, edrophonium, epirubicin, idarubicin, neostigmine, procainamide, propafenone, propofol, pyridostigmine, quinidine, tramadol
Ear Nose Throat No underlying causes
Endocrine Diabetic ketoacidosis, hyperthyroidism, profound hypothyroidism
Environmental Hypothermia
Gastroenterologic No underlying causes
Genetic Andersen cardiodysrhythmic periodic paralysis, Brugada syndrome, congenital heart block, congenital heart disease, Emery-Dreifuss muscular dystrophy, Jervell and Lange-Nielsen syndrome, Kearns-Sayre syndrome, limb-girdle muscular dystrophy type 1B (LGMD1B), muscular dystrophy, myotonic dystrophy, Romano-Ward syndrome, Timothy syndrome
Hematologic No underlying causes
Iatrogenic Cardiac catheterization, cardiac resynchronization therapy, cardiac transplantation, coronary artery bypass grafting, heart surgery, hypertrophic cardiomyopathy alcohol septal ablation, infraclavicular brachial plexus block
Infectious Disease Acute rheumatic fever, myocarditis, pericarditis, septic shock
Musculoskeletal/Orthopedic Muscular dystrophy, myotonic dystrophy, Timothy syndrome
Neurologic No underlying causes
Nutritional/Metabolic Hypermagnesemia, hypocalcemia, metabolic acidosis
Obstetric/Gynecologic No underlying causes
Oncologic Cardiac tumor
Ophthalmologic No underlying causes
Overdose/Toxicity Acetylcholine, amiodarone, anthracyclines, cholinesterase inhibitors, propofol, quinidine, tramadol
Psychiatric Takotsubo cardiomyopathy, severe anorexia nervosa
Pulmonary Hypoxia
Renal/Electrolyte Hyperkalemia, renal failure
Rheumatology/Immunology/Allergy Acute rheumatic fever, neonatal lupus erythematosus
Sexual No underlying causes
Trauma Myocardial contusion, severe brain injury
Urologic No underlying causes
Miscellaneous No underlying causes

Causes in Alphabetical Order

Differentiating Ventricular Escape Beat from other Diseases

  • Junctional escape beat : When the sinus rate falls below the discharge rate of the AV node, this becomes the dominant pacemaker, and the result is called a junctional escape beat. The AV node usually generates a rhythm at 40-60 BPM.
  • Idioventricular rhythm : An escape beat is a form of cardiac arrhythmia, in this case known as an ectopic beat. If there are only one or two ectopic beats, they are considered escape beats. If this causes a semi-normal rhythm to arise it is considered an idioventricular rhythm.
  • Premature ventricular contraction : An absence of P wave activity, associated with a widened QRS complex resembles a PVC, but occuring after a pause of variable duration differentiate ventricular escape beat from PVCs.
  • Complete heart block : In complete or third degree heart block there is sinus node activity but failure of conduction through the AV node. There are P waves dissociated from the ventricular complexes with a rate faster than the ventricular rate that differentiates complete heart block from ventricular escape beat where there is absence of P waves.

Diagnosis

History and Symptoms

The escape arrhythmia is a compensatory mechanism that indicates a serious underlying problem with the SA node or conduction system (commonly due to heart attack or medication side effect), and because of its low rate, it can cause a drop in blood pressure. Some of the symptoms related to hypotension are:

Physcial Examination

  • Bradycardia may be present. The rate is below 40 beats per minute.
  • Tachypnea may be present.
  • Elevated JVP may be seen if heart failure is present.
  • S3 gallop may be heard in the presence of heart failure.

Laboratory Findings

The following laboratory studies should be done, depending upon the cause, while investigating a case of ventricular escape beat.

Electrocardiogram

An electrocardiogram can be used to identify a ventricular escape beat. The QRS portion of the electrocardiogram represents the ventricular depolarization; in normal circumstances the QRS complex forms a sharp sudden peak. For a patient with a ventricular escape beat, the shape of the QRS complex is broader as the impulse can not travel quickly via the normal electrical conduction system.[3]

Factors Affecting Ventricular Escape Beat

  • Ouabain infusion decreases ventricular escape time and increases ventricular escape rhythm. However, a high dose of ouabain can lead to ventricular tachycardia.[2]

References

  1. ↑ C. Andreasen, et al. (2006) Mosby Elsevier, Mosby's Dictionary of Medicine, Nursing and Health Professions 7th edition, p1951
  2. ↑ 2.0 2.1 Banka VS, Scherlag BJ, Helfant RH (1975). "Contractile and electrophysiological responses to progressive digitalis toxicity". Cardiovasc. Res. 9 (1): 65–72. doi:10.1093/cvr/9.1.65. PMID 1122512. Unknown parameter |month= ignored (help)
  3. ↑ Adams MG, Pelter MM (2003). "Ventricular escape rhythms". Am. J. Crit. Care. 12 (5): 477–8. PMID 14503433. Unknown parameter |month= ignored (help)
  4. ↑ Kodama-Takahashi K, Kurata A, Ohshima K; et al. (2003). "Effect of cilostazol on the ventricular escape rate and neurohumoral factors in patients with third-degree atrioventricular block". Chest. 123 (4): 1161–9. doi:10.1378/chest.123.4.1161. PMID 12684307. Unknown parameter |month= ignored (help)


Template:WikiDoc Sources

Retrieved from "https://www.wikidoc.org/index.php?title=Ventricular_escape_beat&oldid=1111273"