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APPROACH TO WIDE QRS COMPLEX TACHYCARDIA. Dr HA TUAN KHANH Dr DAVID TRAN. Content. Definition Causes of WCT Diagnosis criteria Clinical history Physical examination ECG criteria: Brugada criteria, other criteria, findings favoring SVT, VT vs AVRT criteria Management Unstable hemodynamic
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APPROACH TO WIDE QRS COMPLEX TACHYCARDIA Dr HA TUAN KHANH Dr DAVID TRAN
Content • Definition • Causes of WCT • Diagnosis criteria • Clinical history • Physical examination • ECG criteria: Brugada criteria, other criteria, findings favoring SVT, VT vs AVRT criteria • Management • Unstable hemodynamic • Stable hemodynamic
Definition Wide QRS complex tachycardia is a rhythm with a rate of more than 100 b/m and QRS duration of more than 120 ms SVT (20%) VT (80%) Stewart RB. Ann Intern Med 1986
Causes of wide QRS complex tachycardia • Supraventricular tachycardia - with prexsisting BBB - with BBB due to heart rate (aberrant conduction) - antidromic tachycardia in WPW syndrome • Ventricular tachycardia
SVT vs VTPhysical examination • Physical findings that indicate presence of AV dissociation (cannon A waves, variable-intensity S1,variation in BP unrelated to respiration) if present are useful • Termination of WCT in response to maneuvers like Valsalva, carotid sinus pressure, or adenosine is strongly in-favor of SVT but there are well-documented cases of VT responsive to these
SVT vs VTECG criteria: Brugada algorithm Brugada P. Ciculation 1991
Step 4: LBBB - type wide QRS complex VT SVT R wave >40ms notching of S wave small R wave V1 fast downslope of S wave > 70ms Q wave V6 no Q wave
Step 4: RBBB - type wide QRS complex VT SVT qR (or Rs) complex monophasic R wave rSR’ configuration V1 or R/S > 1 R/S ratio < 1 QS complex V6 or
Other ECG criteria • North - west QRS axis deviation • Negative or positive concordance • Fusion beats, capture beats • Ventriculoatrial conduction with block • RBBB morphology with LAD > - 300 • LBBB morphology with RAD > + 900 • Previous ECG show MI or previous ECG show that during sinus rhythm, bifascular block is present, which changes in configuration during tachycardia
Findings favoring SVT • Triphasic pattern in V1 and V6 • Rabbit’s ear • Previous ECG: Preexistent BBB or preexcitation
VT vs AVRTECG criteria Brugada P. Ciculation 1991
Summary : diagnosis evaluation ACC/AHA/ESC guidelines for management of pt with SVT. Circulation 2003
Management – Hemodynamic compromise • Unstable patient, but still responsible with a discernible BP and/or pulse: - Emergent synchronized cardioversion - If the QRS complex and T wave cannot be distinguished accurately → immediate defibrillation • Unstable patient, unresponsive or pulseless → standard ACLS resusciation algorithms
ACLS pulseless arrest algorithm AHA Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Ciurculation 2005
Management – Stable hemodynamic • VT or WCT of uncertain etiology: • Any associated conditions (cardiac ischemia, heart failure, electrolyte abnormalities or drug toxicities) • Class I and III antiarrhythmic drugs - Amiodarone: 150mg IV/10mins followed by an infusion of 1mg/min for 6 hours, then 0,5mg/min - Procainamide: 15-18mg/kg infusion over 25-30mins, followed by 1-4mg/min by continuous infusion - Lidocaine: 1-1,5mg/kg IV/2-3mins followed by an infusion of 1-4mg/min • Urgent or elective cardioversion
Management – Stable hemodynamic • SVT • Vagal maneuvers: carotid sinus pressure (if no carotid bruits) or Valsava maneuver • Adenosine: 6mg over 1-2 seconds. If the initial dose is ineffective, a 12mg dose may be given and repeated once if necessary • Calcium channel blocker (Verapamil 2.5 to 5mg IV) or beta blokers (Metoprolol 5 to 10 mg IV) • Cardioversion
Acute management hemodynamically stable and regular tachycardia ACC/AHA/ESC guidelines for management of pt with SVT. Circulation 2003
Recommendation acute management hemodynamically stable and regular tachycardia ACC/AHA/ESC guidelines for management of pt with SVT. Circulation 2003
Tachycardia algorithm AHA Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Ciurculation 2005