Circumferential myocardial strain in cardiomyopathy with and without left bundle branch block

Journal of Cardiovascular Magnetic Resonance

Research

Idith Haber¹  Peter J Zimetbaum²  Susan B Yeon²  Yuchi Han²  Dana C Peters²  Warren J Manning³  Jonathan Chan⁴ 

[1] Department of Medicine (Cardiology), University of Chicago Medical School, Chicago, IL, USA;Departments of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA;Departments of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA;Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA;Departments of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA;School of Medicine, University of Queensland, Brisbane, Australia;

关键词: Cardiovascular Magnetic Resonance;    Cardiac Resynchronization Therapy;    Late Gadolinium Enhancement;    Left Bundle Branch Block;    Circumferential Strain;   

DOI  :  10.1186/1532-429X-12-2

 received in 2009-08-04, accepted in 2010-01-05,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundCardiac resynchronization therapy (CRT) has been shown to decrease mortality in 60-70% of advanced heart failure patients with left bundle branch block (LBBB) and QRS duration > 120 ms. There have been intense efforts to find reproducible non-invasive parameters to predict CRT response. We hypothesized that different left ventricular contraction patterns may exist in LBBB patients with depressed systolic function and applied tagged cardiovascular magnetic resonance (CMR) to assess circumferential strain in this population.MethodsWe determined myocardial circumferential strain at the basal, mid, and apical ventricular level in 35 subjects (10 with ischemic cardiomyopathy, 15 with non-ischemic cardiomyopathy, and 10 healthy controls). Patterns of circumferential strain were analyzed. Time to peak systolic circumferential strain in each of the 6 segments in all three ventricular slices and the standard deviation of time to peak strain in the basal and mid ventricular slices were determined.ResultsDyskinesis of the anterior septum and the inferior septum in at least two ventricular levels was seen in 50% (5 out of 10) of LBBB patients while 30% had isolated dyskinesis of the anteroseptum, and 20% had no dyskinesis in any segments, similar to all of the non-LBBB patients and healthy controls. Peak circumferential strain shortening was significantly reduced in all cardiomyopathy patients at the mid-ventricular level (LBBB 9 ± 6%, non-LBBB 10 ± 4% vs. healthy 19 ± 4%; both p < 0.0001 compared to healthy), but was similar among the LBBB and non-LBBB groups (p = 0.20). The LBBB group had significantly greater dyssynchrony compared to the non-LBBB group and healthy controls assessed by opposing wall delays and 12-segment standard deviation (LBBB 164 ± 30 ms vs. non-LBBB 70 ± 17 ms (p < 0.0001), non-LBBB vs. healthy 65 ± 17 ms (p = 0.47)).ConclusionsSeptal dyskinesis exists in some patients with LBBB. Myocardial circumferential strain analysis enables detailed characterization of contraction patterns, strengths, and timing in cardiomyopathy patients with and without LBBB.

【 授权许可】

CC BY   
© Han et al; licensee BioMed Central Ltd. 2010