Long-term outcome of cardiac resynchronization therapy in patients with drug-refractory heart failure

Purpose To study the long-term outcome of cardiac resynchronization therapy (CRT) in patients with drug-refractory heart failure patients. Methods All patients fulfilled the standard CRT indication with New York Heart Association (NYHA) class Ⅲ -Ⅳ, QRS duration≥130 ms, LVEDD≥55 mm and LVEF≤35%. Tissue doppler imaging (TDD showed dissynchronization between inter-ventricles and intra-left ventricle. The outcome of CRT was evaluated in terms of QRS width, clinical manifestation and echocardiographic parameters. The duration of follow-up was (15±6) months. Results The operations were successful with no complications. The left ventricular leads were inserted through heart vein in 10 cases, epicardial in 2 cases and bifocal right ventricular pacing in 1 case. The NYHA heart function was enhanced to class II-III and LVEF was improved from (27. 00±3. 84) % before operation to(40. 36±7. 87) % 12 months after CRT (P0. 05). One patient died due to ventricular fibrillation. The QRS duration and LVEDD were significantly decreased after CRT for 12 months[ (176±10.4) ms vs (150±9. 6)ms, and (75. 11±14. 32)mm vs (64.3±18. 70) mm], respectively (P0. 05). The synchronization of inter-ventricles and intra-left ventricle was improved. Conclusions CRT can improve long-term symptoms and heart function by ameliorating synchrony in patients with progressive heart failure.