Premature ventricular complexes

Fig. 1. A 12-lead ECG of multiple RVOT PVCs. The PVC has an inferior axis (positive in the inferior leads – II, III and aVF), propagating from the right to left (positive in lead I) with a left bundle branch block morphology. The RVOT is the most common SOO for idiopathic PVCs.

Fig. 2. Regionalisation of the SOO of a PVC into four quadrants. AMC, aortomitral continuity; APM, anterolateral papillary muscle; Inf., inferior; LAF, left anterior fascicle; LBBB, left bundle branch block; LCC, left coronary cusp; LPF, left posterior fascicle; LV, left ventricular; MB, moderator band; MV, mitral valve; PPM, posteromedial papillary muscle; RBBB, right bundle branch block; RCC, right coronary cusp; RVOT, right ventricular outflow tract; Sup, superior; TV, tricuspid valve.

Fig. 3. Proposed treatment algorithm in patients with PVCs.

Fig. 4. Localising and ablating the PVC SOO. A – colour-coded activation map (CARTO™ system) of the right ventricle with the earliest activation point of a PVC activation indicated in red. B – Local unipolar electrograms at that same site denoted in red. Note the negative (Q) wave signifying an activation front moving away from that location, ie originating from that site. C – Pace mapping with the PASO system demonstrating correlation between activation and pace mapping. D and E – comparison of electrical signals from activation (D) and pace (E) mapping, demonstrating good correlation. Note the polarity discordance in signals between distal (Map d) and proximal (Map P) electrograms, indicating the SOO nearer to the distal tip of the catheter. F – Ablation at the PVC SOO which usually results in the flurry of PVCs – two in this case.