LAUSR

Premature ventricular complexes (PVCs) are common in patients with and without structural heart disease. Although PVCs used to be considered as mostly benign, long-term frequent PVCs may be associated with PVC-induced cardiomyopathy [1,2]. Possible mechanisms include alteration of membrane ionic currents and intracellular calcium handling, alteration in autonomic tone, ventricular dyssynchrony during PVCs, shortened coupling intervals, and post-extrasystolic potentiation [3e6]. PVC ablation has been shown to reverse PVC related LV dysfunction [7e9]. PVCinduced cardiomyopathy is classified as an indication for catheter ablation therapy by European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society Expert [10]. However, the diagnosis of PVC-induced cardiomyopathy continues to be done by exclusion or retrospectively with no definite criteria to prospectively guide the clinical diagnosis. It also remains controversial whether ablation therapy is required for patients with high burden of PVCs who are asymptomatic and have a normal left ventricular ejection fraction (LVEF). PVCs may induce impairment in radial, longitudinal, and circumferential strain. These changes are not able to be detected by standard imaging and newer techniques, such as speckle tracking, may be needed to detect early presence of PVC cardiomyopathy [11]. Two-dimensional speckle-tracking echocardiography has been shown to detect early left ventricular systolic dysfunction before overt changes in conventional echocardiographic measures and could be an indicator of early subclinical myocardial dysfunction in patients with normal LVEF [12]. The presence of abnormal strain measures in patients with frequent PVCs and normal LVEF could potentially be the impetus to treat these PVCs in order to prevent progression to overt LV dysfunction cardiomyopathy. In this issue of the Indian Pacing and Electrophysiology Journal, Fonseca et al. provide the results of a small comparative retrospective study of 21 patient with right ventricular outflow tract PVCs without structural heart disease referred for ablation and 13 matched controls without PVCs who underwent AVNRT ablation [13]. Global and free wall longitudinal strain measurements (GLS and FW-LS) using 2D speckle tracking echocardiography 30e60 days after ablation were compared between the 2 groups. While LV-GLS stayed in the normal range, RVFW-LS and RV-GLS were lower in the PVC group and with a mean lower than the normal range. These findings suggested subclinical myocardial dysfunction in patients with right ventricular outflow tract PVCs. Several