Left Ventricular Improvement after Cardiac Resynchronization Therapy among Ischemic, Non-Ischemic and Right Ventricular Pacing-Induced Cardiomyopathy

Abstract

Background: The difference in the effect of cardiac resynchronization therapy (CRT) in patients with non-ischemic cardiomiopathy (NICM) and RV pacing-induced cardiomyopathy (PACING) hasn’t been fully estimated. Methods and Results: We investigated the effect of CRT between 6 to 12 months after implantation of ischemic cardiomyopathy (ICM), NICM and Pacing group. LV end-systolic diameter (ESD) on echocardiography and serum BNP level before and after CRT implantation were evaluated. Fourty patients (ICM: 9 patients, NICM: 22 patients, PACING: 9 Patients) were implanted CRT-P or CRT-D between January 2006 to September 2010. CRT-P was implanted in 14 patients and CRT-D was in 26 patients. At baseline, ESD and BNP level showed no significant differences among 3 groups. On follow-up periods, ESD and BNP level didn’t change in ICM group (ESD: from 62.3±6.7 to 58.3±7.5 mm, BNP: from 530.9±388.0 to 496.4±280.0 ng/ml, both p=NS). In NICM group, BNP level was significantly decreased but ESD was not (ESD: from 54.3±9.8 to 53.5±10.5 mm, p=NS, BNP: from 583.2±406.6 to 339.7±238.7 ng/ml, p<0.05). In PACING group, ESD and BNP level was significantly decreased (ESD: from 51.2±8.6 to 47.7±9.1 mm, BNP: from 859.6±669.2 to 290.1±421.2 ng/ml, both p<0.05). The change of ESD (δESD) was no significant differences among 3 groups, but the change of BNP (δBNP) was significantly difference in PACING group compared to other groups (both p<0.05). No patients died within 12 months after CRT implantation. Conclusion: RV pacing-induced cardiomyopathy showed significant improvement compared with ICM and NICM group in serum BNP level.