Clinical characteristics and features of frequent idiopathic ventricular premature complexes in the Korean population

Background and Objectives: Frequent ventricular premature complexes (VPCs) increase the risk of cardiomyopathy (CMP). However, most data regarding VPCs have been obtained from Western population and in-hospital patient-based studies. The objective of this study was to define the clinical characteristics and features of idiopathic VPCs in the Korean population. Subjects and Methods: We investigated subjects undergoing transthoracic echocardiography and documented VPC burdens >1% by Holter monitoring in an outpatient clinic at Samsung Medical Center, Korea. We analyzed demographic and clinical features and the nature of the VPCs by electrocardiography (ECG). Results: A total of 666 patients were registered. Mean age was 54.7±16.8 years, and 365 (54.8%) patients were female. Typical VPC-related symptoms, such as palpitation and a dropped beat, were observed in 394 (59.2%) patients. Some patients received beta-blockers (n=95; 14.3%) and anti-arrhythmic agents (n=14; 2.1%). The ECG analysis was performed in 405 patients; 322 (79.5%) exhibited left bundle branch block (LBBB) and 347 (85.8%) exhibited an inferior axis. The precordial R-wave transition was predominantly distributed over V3 in 230 patients (56.6%). Thirty-one patients (4.5%) were diagnosed with VPC-induced CMP. Conclusion: The incidence of frequent VPCs was slightly higher in females, and palpitation was the most frequent complaint. The most common ECG features were LBBB, inferior axis, and late precordial R-wave transition.