Bear Tracks Hypothesis: Discriminating Malignant from Benign Electrocardiographic Features of Idiopathic Ventricular Arrhythmias

Bear Tracks Hypothesis: Ventricular Arrhythmias

Abstract

Idiopathic ventricular arrhythmias (VAs), encompassing ventricular tachycardia (VT) and premature ventricular contractions (PVCs) originating from the right or left ventricular outflow tract (RVOT and LVOT, respectively), are typically regarded as a benign manifestation in patients without evident structural heart disease. However, two potential concerns persist for cardiologists: (1) Idiopathic ventricular fibrillation (IVF) and/or polymorphic ventricular tachycardia (PVT) can sporadically arise from PVCs considered "benign," and (2) malignant VAs stemming from cardiac channelopathies or concealed/early cardiomyopathies may be misidentified as "benign" idiopathic VAs treated solely by catheter ablation without the implantation of implantable cardioverter-defibrillators (ICDs). This review will scrutinize contemporary evidence regarding certain electrocardiographic features indicative of malignant VAs and explore the potential utility of three-dimensional noninvasive imaging techniques in accurately distinguishing truly benign VAs. It is imperative to recognize "malignant" electrocardiographic features prior to ablation procedures for idiopathic VAs, as the elimination of PVCs may not necessarily mitigate the patient's risk. Advanced three dimensional noninvasive imaging techniques will remain crucial in the comprehensive evaluation of patients with ventricular arrhythmias in the future.