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.