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| {{Infobox_Disease | | | __NOTOC__ |
| Name = {{PAGENAME}} |
| | {| class="infobox" style="float:right;" |
| Image = |Lead II rhythm ventricular tachycardia Vtach VT.JPG |
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| Caption = |
| | | [[File:Siren.gif|30px|link=Wide complex tachycardia resident survival guide]]|| <br> || <br> |
| DiseasesDB = 13819 |
| | | [[Wide complex tachycardia resident survival guide|'''Resident'''<br>'''Survival'''<br>'''Guide''']] |
| ICD10 = {{ICD10|I|47|2|i|30}} |
| | |} |
| ICD9 = {{ICD9|427.1}} |
| | {| class="infobox" style="float:right;" |
| ICDO = |
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| OMIM = |
| | | [[File:Physician_Extender_Algorithms.gif|88px|link=Wide complex tachycardia physician extender algorithm]]|| <br> || <br> |
| MedlinePlus = |
| | |} |
| MeshID = D017180 |
| | {{Wide complex tachycardia}} |
| }} | |
| {{CMG}} | | {{CMG}} |
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| {{SK}} WCT; fast and wide; wide and fast; wide-complex tachycardia; wide complex rhythm; SVT with aberrancy; SVT with aberrant conduction; supraventricular tachycardia with aberrancy; VT versus SVT
| | '''For patient information, click [[Wide complex tachycardia (patient information)|here]]''' |
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| == Overview ==
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| '''Wide complex tachycardia''' is defined as a cardiac rhythm of more than 100 beats per minute with a [[QRS duration]] of 120 milliseconds or more. It is critical to differentiate whether the wide complex tachycardia is of ventricular origin and is [[ventricular tachycardia]], or if it is of supraventricular origin with aberrant conduction. Differentiating between these two cause of the wide complex tachycardia is critical because the treatment options are quite different for VT versus [[SVT with abberancy]]. Wide complex tachycardia will be due to [[VT]] in 80% of cases and will be due to [[VT]] in 98% of cases if there's a history of either [[acute MI]] or structural heart disease. Only 7% of patients with SVT will have had a prior myocardial infarction (MI). | |
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| ==Causes==
| | {{SK}} WCT, fast and wide, wide and fast, wide-complex tachycardia, wide complex rhythm, SVT with aberrancy, SVT with aberrant conduction, supraventricular tachycardia with aberrancy, VT versus SVT, broad complex tachycardia |
| A wide complex tachycardia (WCT) can be due to either:
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| ===Ventricular Tachycardia===
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| * [[Ventricular tachycardia]] ([[VT]]) (80% of cases, 98% of cases ff [[coronary heart disease]] or structural heart disease are present)
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| ===Supraventricular Tachycardia===
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| * [[Supraventricular tachycardia]] ([[SVT]]) with aberrant ventricular conduction, which is either new or due to a preexisting left or right [[bundle branch block]] or a preexisting nonspecific [[intraventricular conduction delay]] ([[IVCD]]). The underlying supraventricular rhythm that is aberrantly conducted can be any one of the following rhythms:
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| :* Antegrade conduction down an [[accessory bypass tract]]
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| :* [[Atrial flutter]] with 2:1 conduction and occasional 1:1 conduction
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| :* Automatic [[junctional tachycardia]]
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| :* [[AV nodal reentrant tachycardia]]
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| :* [[AV reentrant tachycardia]] using a bypass tract
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| :* Intraatrial reentrant tachycardia
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| :* [[Paroxysmal atrial tachycardia]]
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| :* SA nodal reentrant tachycardia
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| :* [[Sinus tachycardia]]
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| == Findings Suggestive of VT == | | ==[[Wide complex tachycardia overview|Overview]]== |
| ===History of Ischemics Heart Disease===
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| A history of [[ischmeic heart disease]] or structural heart disease suggests VT. Wide complex tachycardia will be due to VT in 80% of cases and will be due to VT in 98% of cases if there's a history of either acute MI or structural heart disease.
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| ===The Presence of AV Dissociation=== | | ==[[Wide complex tachycardia causes|Causes]]== |
| Although AV dissociation is highly suggestive of VT, it may also be seen in [[junctional tachycardia]]s with retrograde block.
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| ===Duration of the QRS Complex=== | | ==[[Wide complex tachycardia differential diagnosis|Differentiating VT from SVT as a Cause of Wide Complex Tachycardia]]== |
| * A wide complex tachycardia with a [[RBBB]] morphology and a QRS > .14, or [[LBBB]] with a QRS > .16 suggests [[VT]]
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| ===Morphology of the QRS Complexes=== | | ==[[Wide complex tachycardia epidemiology and demographics|Epidemiology and Demographics]]== |
| * The finding of a positive or negative QRS complex in all precordial leads is in favor of [[ventricular tachycardia]].
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| * A monophasic or biphasic RBBB QRS complex in V1. But none of their patients with SVT had a preexisting RBBB. Therefore, this finding is of limited importance. (A Wellens criterion)
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| * 80 to 85% of aberrant beats have a RBBB pattern, but ectopic beats that arise from the LV have a similar morphology.
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| * LBBB with a rightward axis
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| * LBBB with the following QRS morphology
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| *:# R wave in V1 or V2 > 0.03 second
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| *:# any Q wave in V6
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| *:# Onset of the QRS to nadir of the S wave in V1 > 0.06 seconds
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| *:# Notching of the S wave in V1 or V2
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| ===Morphology of Premature Beats During Sinus Rhythm=== | | ==[[Wide complex tachycardia risk factors|Risk Factors]]== |
| * If [[premature ventricular contractions]] ([[PVCs]]) are present on a prior tracing, and if the morphology of the wide complex tachycardia is the same, then it is likely to be ventricular tachycardia.
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| * Previous EKG may show a preexisting [[intraventricular conduction delay]] ([[IVCD]]) which would favor SVT with abberancy.
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| * If there are [[premature atrial contractions]] ([[PAC]])s with aberrant conduction, then the origin of the wide complex tachycardia may be supraventricular.
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| ===The QRS Axis=== | | ==[[Wide complex tachycardia natural history, complications and prognosis|Natural History, Complications and Prognosis]]== |
| *A "Northwest axis" with a [[QRS axis]] in the RUQ between -90 and +180 degrees favors [[ventricular tachycardia]]
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| ===Capture Beats===
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| * Rare, but one of the strongest pieces of evidence in favor of VT.
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| * SVT with aberrancy rarely follows a beat with a short cycle length.
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| ===Fusion Beats===
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| * Rare but also strongly suggests VT.
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| ===Vagal Manuevers===
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| * VT is generally not affected by vagal stimulation.
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| * May terminate reentrant arrhythmias
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| ===Atrial pacing===
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| * A pacing wire is placed in the RA and the atrium is stimulated at a rate faster than the tachycardia.
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| * If ventricular capture occurs and the QRS is normal in duration, then one can exclude the possibility of aberrant conduction.
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| ===Onset of the Tachycardia===
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| * Diagnosis of SVT made if the episode is initiated by a premature P wave.
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| * If the paroxysm begins with a QRS then the tachycardia may be either ventricular or junctional in origin.
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| * If the first QRS of the tachycardia is preceded by a sinus p wave with a PR interval shorter than that of the conducted sinus beats, the tachycardia is ventricular.
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| ===His Bundle Recording===
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| * In SVT, each QRS is preceded by a His bundle potential.
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| * In VT there is no preceding His deflection.
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| * The retrograde His deflection is usually obscured by the much larger QRS complex.
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| ===Regularity of the Rhythm===
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| ====Regular====
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| * VT (slight irregularity of RR)
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| * SVT with aberrancy: Sinus, atrial tachycardia (AT), or Flutter.
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| * Antidromic atrioventricular reentrant tachycardia (AVRT)
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| ====Irregular====
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| * The first 50 beats of VT can be irregular
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| * SVT with aberrancy: [[Atrial fibrillation]], multifocal atrial tachycardia (MAT)
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| * [[Atrial fibrillation]] with bypass tract
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| * The mechanism of SVT with aberrancy is usually concealed retrograde conduction. The ventricular beat penetrates the right branch (RB) or left branch (LB). When the next supraventricular activation front occurs that bundle is refractory and if conduction can occur, it will proceed down the other bundle. Since the RB has a longer refractory period than the LB, a right bundle branch block (RBBB) morphology is more common.
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| * Other mechanisms of “rate related aberrancy” are preexisting bundle branch block (BBB), physiologic (phase 3) aberration and use dependent aberration secondary to medication. In physiologic aberration, the stimulus comes to the His-Purkinje system before it has fully recovered from the previous stimulus. The ensuing activation is either blocked or conducts slowly. Again, the RB is the one more at risk. Most commonly seen at the onset of paroxysmal supraventricular tachycardia (PSVT), but can become sustained.
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| * In use-dependent aberration, a patient on and anti-arrhythmic (especially class Ic agents) will have a progressive decrement in ventricular conduction rate the more it is stimulated. During faster heart rates, less time is available for the drug to dissociate from the receptor and an increased number of receptors are blocked.
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| ===Pearls from Mark E. Josephson===
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| * In a wide complex tachycardia with [[right bundle branch block]] ([[RBBB]]) morphology with normal or inferior axis, VT is associated with an R/S ratio may be >1, and [[SVT]] with an R/S ratio <1
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| *If the [[QRS]] during the wide complex tachycardia is narrower than in normal [[sinus rhythm]] ([[NSR]]), this suggests [[VT]]
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| === Differentiation of VT from Antidromic AVRT ===
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| * Angina pectoris (AP) activate ventricles from base to apex by virtue of their location in the atrioventricular (AV) ring. This results in predominately positive QRS complexes in V4-V6. If negative, favors VT. For same reason, qR complexes in V2-V4 cannot be found in AVRT unless there is preexisting heart disease.<ref>Brugada P, Brugada J, Mont L et al. A new approach to the differential diagnosis of a regular tachycardia with wide QRS complex. Circulation. 1991;83: 1649-1659. PMID 2022022</ref> <ref>Kindwall KE, Brown, J, Josephson ME. Electrocardiographic criteria for ventricular tachycardia in wide complex left bundle branch block morphology tachycardias. Am J Cardiology. 1988; 61:1279-1283. PMID 3376886</ref> <ref>Podrid P, Brugada P. Approach to wide QRS complex tachycardias. Up To Date. 1998.</ref>
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| * Because the atria are part of the circuit in AVRT, any relationship other than 1:1 of P and QRS means VT (100%).
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| ==ACC Algorithm for Distinguishing SVT from VT==
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| [[File:Wide complex tachycardia algorithm.png|center|ACC algorithm]]
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| The above figure is adpated from the American College of Cardiology algorithm.
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| ==Diagnosis== | | ==Diagnosis== |
| === History===
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| The patient should be asked about drugs that are associated with ventricular tachycardia and if there is a history of ischemic heart disease which would dramatically increase the odds that the rhythm is VT. Wide complex tachycardia will be due to [[VT]] in 80% of cases and will be due to [[VT]] in 98% of cases if there's a history of either [[acute MI]] or structural heart disease. Only 7% of patients with SVT will have had a prior myocardial infarction (MI). VT or an accelerated idioventricular rhythm can be seen following reperfusion in STEMI. Digoxin, antiarrhythmics, phenothiazines, TCAs, and pheochromocytoma may also cause VT. Recent procedures such as cardiac catheterization, DC countershock, repair of congenital lesions are all associated iwth VT. A family history of [[sudden cardiac death]], a history of a [[channelopathy]] associated with [[arrhythmias]], and the hereditary [[Long QT syndrome]], and [[Brugada syndrome]] are all associated with VT.
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| ===Symptoms ===
| | [[Wide complex tachycardia history and symptoms|History and Symptoms]] | [[Wide complex tachycardia physical examination|Physical Examination]] | [[Wide complex tachycardia laboratory findings|Laboratory Findings]] | [[Wide complex tachycardia electrocardiogram|Electrocardiogram]] |
| *[[Shortness of breath]]
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| *[[Syncope]]
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| *[[Sudden cardiac death]] would suggest a diagnosis of [[ventricular tachycardia]]
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| === Physical Examination === | | ==Treatment== |
| * Vitals should be obtained to assess hemodynamic stability and guide therapy
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| * [[Cannon-a waves]] are a manifestation of [[AV dissociation]] and suggest VT
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| * [[Carotid sinus massage]] (CSM)/Valsalva: ST can gradually slow. MAT, AT, Flutter, and AF may transiently slow. An AV nodal dependent WCT may terminate. AV dissociation may become more apparent with CSM in VT. VT can terminate with CSM
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| ==Electrocardiogram==
| | [[Wide complex tachycardia medical therapy|Medical Therapy]] | [[Wide complex tachycardia primary prevention|Primary Prevention]] |
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| * Extreme axis deviation favors VT. Especially -90 to -180 or “northwest” or “superior” axis. (23% of SVT will have SAD)
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| * QRS duration >140 msec favors VT (21% of VT will have QRS <140 msec)
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| * AV dissociation is demonstrated in only 21% of VT
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| * Morphologic Criteria
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| *:* 4% of SVT and 6% of VT did not fulfill criteria in any lead
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| *:* 40% will have discordance between V1/V2 and V5/V6. One lead may suggest VT while another suggests SVT.
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| * An algorithmic approach was proposed by Brugada in 1991. It has a reported sensitivity of 99% and specificity of 97%.
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| {| class="wikitable" font-size="75%"
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| |- style="text-align:center;background-color:#6EB4EB;"
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| |+'''An overview of ventricular tachycardias''', follow the [[media:wideQRS_tachycardia_flow.png|wide complex tachycardia flowchart]]
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| |-
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| !
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| !example
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| !regularity
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| !atrial frequency
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| !ventricular frequency
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| !origin (SVT/VT)
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| !p-wave
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| !effect of adenosine
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| |-
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| | colspan="8" style="text-align:left;background-color:#cfefcf;" | '''Wide complex (QRS>0.12)'''
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| |-
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| ! [[Ventricular Tachycardia]]
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| | [[Image:vt_small.svg|200px]]
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| | regular (mostly)
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| | 60-100 bpm
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| | 110-250 bpm
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| | ventricle (VT)
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| | [[AV-dissociation]]
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| | no rate reduction (sometimes accelerates)
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| |-
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| ! [[Ventricular Fibrillation]]
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| | [[Image:vf_small.svg|200px]]
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| | irregular
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| | 60-100 bpm
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| | 400-600 bpm
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| | ventricle (VT)
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| | [[AV-dissociation]]
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| | none
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| |-
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| ! [[Ventricular Flutter]]
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| | [[Image:vflutt_small.svg|200px]]
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| | regular
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| | 60-100 bpm
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| | 150-300 bpm
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| | ventricle (VT)
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| | [[AV-dissociation]]
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| | none
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| |-
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| ! [[Accelerated Idioventricular Rhythm]]
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| | [[Image:aivr_small.svg|200px]]
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| | regular (mostly)
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| | 60-100 bpm
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| | 50-110 bpm
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| | ventricle (VT)
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| | [[AV-dissociation]]
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| | no rate reduction (sometimes accelerates)
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| |-
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| ! [[Torsade de Pointes]]
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| | [[Image:tdp_small.svg|200px]]
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| | regular
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| | 150-300 bpm
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| | ventricle (VT)
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| | [[AV-dissociation]]
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| | no rate reduction (sometimes accelerates)
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| |-
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| ! [[Bundle-branch re-entrant tachycardia]]*
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| | [[Image:bb_reentry_small.svg|200px]] | |
| | regular
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| | 60-100 bpm
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| | 150-300 bpm
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| | ventricles (VT)
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| | [[AV-dissociation]] | |
| | no rate reduction
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| |-
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| |colspan="8"|*) Bundle-branch re-entrant tachycardia is extremely rare
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| |}
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| ===Electrocardiographic Examples===
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| <gallery>
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| Image:wide_qrs_tachy_AAM3.png|Wide complex tachycardia. LBBB configuration. Absence of RS in the chest leads. [[AV dissociation]] is present. Conclusion: [[VT]]
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| Image:wide_qrs_tachy_AAM4.png|Wide complex tachycardia. LBBB configuration. Absence of RS in the chest leads. [[AV dissociation]] is present. Conclusion: [[VT]]
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| </gallery>
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| == Treatment ==
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| ===Defibrillation===
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| Indications for defibrillation include the following:
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| * [[Chest pain]]
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| * [[Congestive heart failure]] ([[CHF]])
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| * [[Hypotension]] with symptoms
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| * [[Loss of consciousness]]
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| * [[Seizure]]
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| === Acute Pharmacotherapies ===
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| * '''If stable''': (More patients than you think)
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| * '''DO NOT USE''' Ca2+ Channel blocker, [[Digoxin]] or [[Adenosine]] if you don't not know the etiology of the Wide Complex Tachycardia. Ca2+ Channel blockers and Digoxin can lead to accelerated conduction down a bypass tract and [[VF]].
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| * Though ACLS guidelines recommend a diagnostic trial of [[Adenosine]], it can precipitate [[VF]] in some patients with SVT. Patients who have underlying coronary disease may become ischemic from coronary steal. Rhythm can degenerate and lead to [[VF]] that cannot be resuscitated. Furthermore, some [[VT]] (esp those with structurally normal hearts) are [[adenosine]] responsive and can terminate.
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| *:# Etiology Uncertain
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| *:#:* [[Pronestyl]] 15mg/kg load over 30 minutes then 2-6mg/min gtt
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| *:# [[Ventricular Tachycardia]] with active ischemia
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| *:#:* [[Lidocaine]] 1 mg/kg q5-10 min up to 3 times then 2-6mg.min gtt
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| *:#:* If unsuccessful, [[Pronestyl]] as above
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| *:#:* If unsuccessful, IV [[Amiodarone]] 150-300 load over 15-20min. 30-60mg/hr gtt for total of 1gram
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| *:# [[Ventricular Tachycardia]] in Setting of [[Cardiomyopathy]]
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| *:#:* Skip [[Lidocaine]] and go straight to [[Pronestyl]]
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| *:# Positively [[SVT]] with aberrancy
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| *:#:* [[Adenosine]] 6mg rapid IV bolus in large vein. May repeat with 12mg x2.
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| *:#:* [[Lopressor]] 2.5-5.0mg IV
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| *:#:* [[Diltiazem]] 10-20mg bolus followed by gtt 5-20mg/hr
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| *:#:* [[Verapamil]] 2.5-5.0mg bolus.
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| *:#:* Avoid [[Digoxin]]. Takes too long to work and can be proarrhythmic
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| *:#:* [[Pronestyl]] as above
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| *:# Antidromic AVRT
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| *:#:* If 100% positive [[AF]] is not underlying, can terminate with a nodal blocker
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| *:#:* If unsure, [[Pronestyl]] as above
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| [[Category:Electrophysiology]]
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| [[Category:Cardiology]]
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| {{WikiDoc Help Menu}}
| | ==Case Studies== |
| {{WikiDoc Sources}}
| | [[Wide complex tachycardia case study one|Case #1]] |
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| == References ==
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| {{Reflist|2}}
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| [[Category:Electrophysiology]] | | [[Category:Electrophysiology]] |
| [[Category:Cardiology]] | | [[Category:Cardiology]] |
| | [[Category:Arrhythmia]] |
| [[Category:Emergency medicine]] | | [[Category:Emergency medicine]] |
| [[Category:Intensive care medicine]] | | [[Category:Intensive care medicine]] |
| | [[Category:Arrhythmia]] |
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