Table 6.
Twelve-lead ECG during VT
ECG during VT | Description | Suggestive cause of ES/site of origin |
---|---|---|
TdP | PVT with ‘QRS twisting' | Acquired or congenital LQT |
PVT | VT with continually changing QRS morphology | Acute ischaemia, primary electrical disease (BrS, SQT, IVF, CPVT, ERS) |
Bidirectional VT | Alternating QRS morphology (beat-to-beat) | CPVT, digitalis intoxication, Andersen–Tawil syndrome |
LBBB-like and inferior axisa | ARVC, idiopathic VT from the RVOT (normal heart) | |
RBBB-like VT with left superior axis (LAH-like, less frequently right inferior axis LPH-likea)83 | Narrow QRS (100–140 ms), short RS interval (onset of R wave to nadir of S wave of 60–80 ms), r < R′ in V1 | Left ventricular fascicular VT (usually normal heart) |
QRS broad (≥150 ms), absence of rsR′ in V1 | Papillary muscle VT | |
QRS broad (≥155 ms), R ≥ s in V5, may be positive QRS concordance | Peri-mitral VT | |
Fast (>200 b.p.m.) LBBB-like VT, with rapid downstroke of S wave in the anterior precordial leads, QRS during sinus rhythm (usually broad) may be identical to QRS duringa VT84,85 | Short QRS onset—the R-wave peak time (R-wave peak time) and fast downstroke of S wave in V1–V2 | Bundle branch re-entrant tachycardia (SHD) |
RBBB-like VT with pseudo-delta wave and broad RS interval,4 absence of q waves in inferior leads and presence in Leada I86–88 | Pseudo-delta wave ≥34 ms (interval from the earliest ventricular activation to the earliest fast deflection in any precordial lead) R-wave peak time in V2 ≥85 ms Shortest RS complex ≥121 ms (in any precordial lead) |
VT with epicardial origin (SHD) |
aLBBB-like pattern is characterized by a negative net amplitude of QRS complexes in leads V1 and/or V2 and RBBB-like by a positive net QRS amplitude in these leads.
ARVC, arrhythmogenic right ventricular cardiomyopathy; BrS, Brugada syndrome; CPVT, catecholaminergic polymorphic ventricular tachycardia; ECG, electrocardiogram; ES, electrical storm; ERS, early repolarization syndrome; IVF, idiopathic ventricular fibrillation; LAH, left anterior hemiblock; LBBB, left bundle branch block; LPH, left posterior hemiblock; LQT, long QT; PVT, polymorphic ventricular tachycardia; RBBB, right bundle branch block; RVOT, right ventricular outflow tract; SHD, structural heart disease; SQT, short QT; TdP, torsade de pointes; VT, ventricular tachycardia.