Strain-time curve analysis by speckle tracking echocardiography in cardiac resynchronization therapy: Insight into the pathophysiology of responders vs. non-respondersReport as inadecuate




Strain-time curve analysis by speckle tracking echocardiography in cardiac resynchronization therapy: Insight into the pathophysiology of responders vs. non-responders - Download this document for free, or read online. Document in PDF available to download.

Cardiovascular Ultrasound

, 14:14

First Online: 18 April 2016Received: 09 March 2016Accepted: 08 April 2016

Abstract

BackgroundPatients with non-ischemic heart failure etiology and left bundle branch block LBBB show better response to cardiac resynchronization therapy CRT. While these patients have the most pronounced left ventricular LV dyssynchrony, LV dyssynchrony assessment often fails to predict outcome. We hypothesized that patients with favorable outcome from CRT can be identified by a characteristic strain distribution pattern.

MethodsFrom 313 patients who underwent CRT between 2003 and 2006, we identified 10 patients who were CRT non-responders no LV end-systolic volume LVESV reduction with non-ischemic cardiomyopathy and LBBB and compared with randomly selected CRT responders n = 10; LVESV reduction ≥15 %. Longitudinal strain εlong data were obtained by speckle tracking echocardiography before and after 9 ± 5 months CRT implantation and standardized segmental εlong-time curves were obtained by averaging individual patients.

ResultsIn responders, ejection fraction EF increased from 25 ± 9 to 40 ± 11 % p = 0.002, while in non-responders, EF was unchanged 20 ± 8 to 21 ± 5 %, p = 0.57. Global εlong was significantly lower in non-responders at pre CRT p = 0.02 and only improved in responders p = 0.04 after CRT. Pre CRT septal εlong -time curves in both groups showed early septal contraction with mid-systolic decrease, while lateral εlong showed early stretch followed by vigorous mid to late contraction. Restoration of contraction synchrony was observed in both groups, though non-responder remained low amplitude of εlong.

ConclusionsCRT non-responders with LBBB and non-ischemic etiology showed a similar improvement of εlong pattern with responders after CRT implantation, while amplitude of εlong remained unchanged. Lower εlong in the non-responders may account for their poor response to CRT.

KeywordsCardiac resynchronization therapy Left bundle branch block Dyssynchrony AbbreviationsCRTcardiac resynchronization therapy

LVleft ventricular

LBBBleft bundle branch block

LVESVleft ventricular end-systolic volume

EFejection fraction

εlongLongitudinal strain

ECGelectrocardiogram

NYHANew York Heart Association

CRT-Dbiventricular implantable cardioverter defibrillator

LVEDVleft ventricular end-diastolic volume

Download fulltext PDF



Author: Andrew C. Y. To - Rodolfo D. Benatti - Kimi Sato - Richard A. Grimm - James D. Thomas - Bruce L. Wilkoff - Deborah Ag

Source: https://link.springer.com/article/10.1186/s12947-016-0057-4







Related documents