Abstract 16666: Electrocardiographic Identification of Idiopathic Ventricular Arrhythmia With a Right Bundle Branch Block and Superior Axis
Background: A right bundle branch block (RBBB) with left superior axis ECG morphology is common in patients with idiopathic ventricular arrhythmia (VA) originating from left posterior fascicular (LPF), LV-posterior papillary muscles (LV-PPM) and mitral annulus (MA). We have recently described our patients with VA that arises from epicardial posteroseptal cardiac crux. We investigated electrocardiographic and clinical characteristics of crux-VA, and compared them with other RBBB and superior axis VAs.
Methods and Results: Among 223 patients with idiopathic VA referred for ablation, we analyzed surface ECG of 37 (16 %) patients with RBBB and left superior axis: 7 from cardiac crux, 15 from LPF, 11 from LV-PPM and 4 from MA. Mean age was 49 ±12 years (19 males and 18 females). Figure 1 showed the typical QRS morphology during VA. MDI≧0.55 could distinguish crux-VT from LPF and LV-PPM (P<0.0001). Prominent R wave in aVR could distinguish crux-VT from LPF and MA-VA (P<0.0001), and QS or R / S < 0.2 in V6 could distinguish crux-VT from LPF, LV-PPM and MA-VA (P<0.0001).
Conclusions: We described the ECG characteristics that different crux-VA from other VAs with RBBB and left superior axis. QS or R / S < 0.2 in V6 could distinguish crux-VA from other VAs with a high accuracy (sensitivity 100 %, specificity 97 %). We could not distinguish LPF from LV-PPM. MA-VT presented with QS in inferior leads and MDI≧0.55, but we could distinguish from crux-VA from MA-VA with R or Rs wave in V6. This measure might be useful for counseling patients and planning an epicardial ablation strategy.
- © 2013 by American Heart Association, Inc.