Electrocardiographic findings in patients with arrhythmogenic cardiomyopathy and right bundle branch block ventricular tachycardia

Figures

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  Figure 1. Schematic representation of the presumed right bundle branch block (RBBB)-ventricular tachycardia (VT) sites of origin (SOOs) in a 17-segment left ventricular (LV) model based on the VT QRS axis-derived methodology from Andreu et al.10 (A) The whole study population (n = 70), the two most frequently involved SOOs were the infero-apical segment and antero-basal segment. The inferior wall exhibited 31 (46%) SOOs, followed by the lateral wall (n = 17, 25%), anterior wall (n = 15, 22%), and septum (n = 4, 6%). (B) Putative SOOs in the two most-common underlying genotypes. The most frequent putative SOO in PKP2 carriers (n = 8) was the inferior apex, whereas patients with desmoplakin (DSP)-related ACM (n = 11) mainly exhibited infero-apical, inferobasal, and antero-basal putative SOOs.

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  Figure 2. Representative examples of right bundle branch block (RBBB)-ventricular tachycardias (VTs) and their corresponding sinus rhythm (SR) electrocardiography (ECG) graphs. (A) Top: SR ECG showing T-wave inversion (TWI) in lateral leads and low QRS voltage in lateral limb leads. Bottom: RBBB-VT with a left QRS axis-positive concordance in the precordial leads, corresponding to an LV latero-basal exit. (B) Top: SR ECG showing TWI and low QRS voltage in inferior leads. Bottom: RBBB-VT with superior QRS-axis and positive concordance in the precordial lead, suggesting an LV infero-basal exit.

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  Figure 3. Right bundle branch block (RBBB)-ventricular tachycardia (VT) mapping in a 32-year-old woman with desmoplakin (DSP) biventricular arrhythmogenic cardiomyopathy and a subcutaneous implantable cardioverter-defibrillator. (A–C) Epicardial bipolar voltage mapping (0.5–1.5 mV) performed with a Pentaray multipolar catheter (Biosense Webster, Irvine, CA) showing extensive RV epicardial scar and patchy LV scar at the inferior and lateral walls. (A) antero-posterior (AP) view, (B) left lateral (LL) view, (C) postero-anterior (PA) view. (D) Endocardial LV mapping showing limited anterior and latero-basal scar. (E) Activation mapping of the superior axis clinical RBBB-VT showing an epicardial infero-lateral LV critical isthmus. (F) During the same procedure, an inferior axis RBBB-VT was induced and used an epicardial lateral isthmus located in the vicinity of the clinical VT.

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  Figure 4. A case-based illustration of a 48-year-old man with biventricular mutation-negative arrhythmogenic cardiomyopathy [definite Task Force Criteria (TFC) diagnosis with major depolarization, repolarization and structural criteria]. (A) The clinical right bundle branch block (RBBB)-ventricular tachycardia (VT) with an early precordial transition and QRS is compatible with the Marchlinki et al. description suggesting an infero-apical right ventricular (RV) origin. (B) Endocardial RV bipolar voltage mapping (Pentaray) showing a typical sub-tricuspid scar area. (C–E) Epicardial bipolar voltage mapping showing extensive RV and inferolateral left ventricular (LV) scar. (F) Activation mapping showing the macro-reentrant clinical VT with a critical isthmus located in the epicardial infero-apical LV. (G) Mid-diastolic potentials recorded within the critical isthmus. (H) Pace-mapping shows a transition from high (95%) to low (70%) concordance with the clinical VT, a finding compatible with a critical isthmus site.