APPROACH TO WIDE QRS COMPLEX TACHYCARDIA
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
APPROACH TO WIDE QRS COMPLEX TACHYCARDIA
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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