Ezzeddine, Fatima

AbstractBackgroundSeveral chemotherapy agents are associated with the development of non‐ischemic cardiomyopathy (NIC). When chemotherapy‐induced cardiomyopathy (CHIC) is associated with left bundle branch block (LBBB) and a left ventricular ejection fraction (LVEF) 35% or lower, cardiac resynchronization therapy (CRT) is often utilized to improve cardiac function and relieve symptoms.ObjectiveTo determine the echocardiographic and clinical outcomes of CRT in patients with CHIC.MethodsThe study included 29 patients with CHIC (CHIC group) and 58 patients with other types of NIC (control group) who underwent CRT implantation between 2004 and 2017. The primary endpoints were changes in LVEF, left ventricular end‐systolic diameter (LVESD), and left ventricular end‐diastolic diameter (LVEDD) at 6–18 months after CRT. The secondary outcomes included changes in left ventricular global longitudinal strain (GLS), systolic strain rate (SRS), early diastolic strain rate (SRE), and overall survival.ResultsOut of 29 patients with CHIC, 62.1% received chemotherapy for lymphoma, 13.7% for breast cancer, and 24.1% for sarcoma. The agent implicated in 93.1% of the patients was an anthracycline. Half of the patients had LBBB. The mean baseline LVEF was 28% ± 8%. The mean baseline QRS duration was 146 ± 26 ms. Twenty‐eight patients had post‐CRT follow‐up data. CRT was associated with improvement in echocardiographic outcomes in the CHIC group and the control group. There was no difference in overall survival between the two groups (log‐rank p = .148).ConclusionCRT improves left ventricular function and reverses remodeling in patients with CHIC.

AbstractBackgroundChronic left bundle branch block (LBBB) can lead to LBBB‐mediated cardiomyopathy from left ventricular dysynchrony. His‐bundle pacing (HBP) results in direct electrical synchrony using the native His‐Purkinje system, providing a novel treatment for this cardiomyopathy.ObjectiveTo assess the feasibility of HBP for cardiac resynchronization therapy (CRT) in LBBB‐mediated cardiomyopathy patients.MethodsRetrospective database review was conducted on patients who underwent CRT by the HBP capable provider at Indiana University Health and Eskenazi Hospital from August 2015 to August 2017. A subset of patients who met the predefined syndrome criteria of LBBB‐mediated cardiomyopathy who underwent HBP were identified. Clinical, echocardiographic, and electrocardiographic variables were extracted at baseline and follow‐up.ResultsNine patients had cardiomyopathy and LBBB. Among those two were lost to follow‐up. Seven patients were included in the analysis. The average time from device implantation to the last follow‐up was 14.5 months. Left ventricular ejection fraction improved on average from 25% to 50% (p = .0001). The left ventricular end‐systolic dimension decreased from 47 to 37 mm (p = .003) and the left ventricular end‐diastolic dimension decreased from 55 to 48 mm (p = .03). QRS duration with HBP‐CRT decreased from 152 to 115 ms. New York Heart Association classification improved from an average of 2.7–2.ConclusionHBP is a viable technique for pursuing CRT in patients with LBBB‐mediated cardiomyopathy.