A Case of Heart Failure Caused by Frequent Premature Ventricular Contractions

摘要

A 43-year-old woman was found to have premature ventricular contractions (PVCs) during a health check conducted 6 months ago. She was admitted to our hospital 1 month ago because of heart failure. Frequent PVCs occurring in a bigeminal or trigeminal rhythm originated from the right ventricular outflow tract (RVOT), and the total heart rate was 62,830 pulses (48%). The patient was diagnosed with heart failure caused by frequent PVCs. We performed a catheter ablation under the guidance of an electroanatomic mapping system. PVCs of 2 types were detected, and PVC1 with a notch in the inferior axis was frequently observed. Activation mapping revealed that the free wall of the RVOT was the site of earliest activation. After ablation, PVC1 and PVC2 disappeared but PVC3 and later PVC4 appeared. The notch shape of the PVCs changed. Repeat activation mapping of PVC4 showed that the earliest excited site was now the posterior wall of the right ventricle (the initial deflection preceded the QRS complex during the PVCs by 40 ms). Ablation of the posterior wall completely inhibited the PVCs. On day 3 after the ablation, the brain natriuretic peptide levels decreased from 1,294 to 86 pg/dL, indicating significant improvement in heart failure. An echocardiogram taken 3 months after discharge revealed that the ejection fraction had improved by 50–71%.