Novel electrocardiographic criteria for diagnosis of premature ventricular complexes arising from the base of left ventricle.

PURPOSE: We report new electrocardiographic criteria (ECG) for localizing premature ventricular complexes (PVCs) originating from the base of the left ventricle (LV). METHODS: QRS deflection (positive negative or negative positive) in lead aVR and aVL respectively, were evaluated in 41 PVC/VT cases. RESULTS: There were a total of 41 patients, age 64 ± 11 years. Twelve patients had QRS deflection in aVR which were completely opposite to the deflection in aVL. If the PVC originated from basal septum, aVR was negative while aVL positive and vice versa when it was from the baso-lateral LV. PVCs from other LV sites had aVR and aVL deflection in the same direction. The ECG criteria had a sensitivity and specificity of 91% and 84%, respectively. CONCLUSION: We propose a new ECG criterion to localize PVCs originating from the base of the LV.

Unique features of epicardial ventricular arrhythmias/premature ventricular complexes ablated from coronary venous system in veteran population.

INTRODUCTION: Ventricular arrhythmias/premature ventricular complexes (VA/PVCs) that can be ablated from within the coronary venous system (CVS) have not been described in the United States Veterans Health Administration (VHA) population. We retrospectively studied the VA/PVCs ablations that were performed in the VHA population. METHODS: Data from 42 consecutive patients who underwent VA/PVCs ablation at Veterans Affairs Hospital, Indianapolis, IN, with 44 VA/PVCs was included in the study. Patients were divided into two groups (CVS group [n = 10], and non-CVS group [n = 32]) based on where the earliest pre-systolic activation was seen with >95% pacematch. RESULTS: The mean age in CVS group was 65 ± 8 years versus 64 ± 12 years (p = 0.69) in non-CVS group. Overall there was a statistically significant reduction in PVC burden post ablation (27.7% (pre-ablation) versus 4.7% (post-ablation). In the 10 patients in the CVS group, either ablation or catheter-related mechanical trauma resulted in complete (n = 6 [60%]) or partial (n = 4 [40%]) long-term suppression of VA/PVCs. Right bundle branch block-type VA/PVC (9/11: 82%) was the most common morphology in the CVS group, whereas in the non-CVS group, this type was seen in only 3/33 (9%). The CVS group (25% of total VA/PVCs) had shorter activation time compared to non CVS group. CONCLUSION: In our experience VA/PVCs with electrocardiograms suggestive of epicardial origin can often be safely and successfully ablated within the coronary venous system. These arrhythmias have unique features in Veterans patient population.

Digoxin: its role in contemporary medicine.

Digoxin has been a key therapeutic for heart failure and atrial tachyarrhythmias for over 200 years following Withering's groundbreaking work depicting the therapeutic benefit of the common botanical foxglove in his 1785 monograph. The use of digoxin preceded any randomised evidence or even basic understanding of its mechanism of action. Over the past two decades, there has been mounting evidence further challenging the safety and efficacy of digoxin, while multiple other therapies for both heart failure and atrial tachyarrhythmias have proven to be more effective and safe. Altogether, digoxin still has an important role in contemporary pharmacotherapeutics, though its role remains controversial and should be reserved for selective patients and clinical situations, with careful attention to serum concentrations.