RESYNCHRONIZATION RESPONSE EVALUATED BY SPECKLE-TRACKING RADIAL STRAIN IS ASSOCIATED WITH MYOCARDIAL AUTOPHAGY IN SUBJECTS UNDERGOING CARDIAC RESYNCHRONIZATION THERAPY

Despite the success of cardiac resynchronization therapy (CRT) for treating heart failure (HF), the rate of nonresponders remains 30%. Improvements to CRT require understanding of reverse remodeling and the relationship between electrical and mechanical measures of synchrony. The objective was to utilize electrocardiographic imaging (ECGI, a method for noninvasive cardiac electrophysiology mapping) and speckle tracking echocardiography (STE) to study the physiology of HF and reverse remodeling induced by CRT. We imaged 30 patients (63% male, mean age 63.7 years) longitudinally using ECGI and STE. We quantified CRT-induced remodeling of electromechanical parameters and evaluated a novel index, the electromechanical delay (EMD, the delay from activation to peak contraction). We also measured dyssynchrony using ECGI and STE and compared their effectiveness for predicting response to CRT. EMD values were elevated in HF patients compared to controls. However, the EMD values were dependent on the activation sequence (CRT-paced vs. un-paced), indicating that the EMD is not intrinsic to the local tissue, but is influenced by factors such as opposing wall contractions. After 6 months of CRT, patients had increased contraction in native rhythm compared to baseline pre-CRT (baseline: −8.55%, 6 months: −10.14%, p = 0.008). They also had prolonged repolarization at the location of the LV pacing lead. The pre-CRT delay between mean lateral LV and RV electrical activation time was the best predictor of beneficial reduction in LV end systolic volume by CRT (Spearman’s Rho: −0.722, p < 0.001); it outperformed mechanical indices and 12-lead ECG criteria. HF patients have abnormal EMD. The EMD depends upon the activation sequence and is not predictive of response to CRT. ECGI-measured LV activation delay is an effective index for CRT patient selection. CRT causes persistent improvements in contractile function.

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Comparison between cardiac magnetic resonance and speckle-tracking echocardiography in prediction of cardiac resynchronization therapy outcomes

Al-Azhar Assiut Medical Journal ◽

10.4103/azmj.azmj_107_20 ◽

2021 ◽

Vol 19 (2) ◽

pp. 237

Author(s):

Mohamd Bahaa EldenMohamed Khedrawy ◽

Mohamed Salah El-DinAbdel Salam ◽

MohamedMahmud Ahmed ◽

Wesam EmamAli Elmozy

Keyword(s):

Cardiac Magnetic Resonance ◽

Magnetic Resonance ◽

Cardiac Resynchronization Therapy ◽

Speckle Tracking ◽

Speckle Tracking Echocardiography ◽

Cardiac Resynchronization ◽

Resynchronization Therapy ◽

Therapy Outcomes

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Abstract 1604: Response to Cardiac Resynchronization Therapy Differs Between Patients With and Without Previous Right Ventricular Pacing

Circulation ◽

10.1161/circ.116.suppl_16.ii_335-b ◽

2007 ◽

Vol 116 (suppl_16) ◽

Author(s):

Andrea M Thelen ◽

Christopher L Kaufman ◽

Kevin V Burns ◽

Daniel R Kaiser ◽

Aaron S Kelly ◽

...

Keyword(s):

Heart Failure ◽

Cardiac Resynchronization Therapy ◽

Systolic Function ◽

Radial Strain ◽

Left Ventricular ◽

Doppler Imaging ◽

Cardiac Resynchronization ◽

Resynchronization Therapy ◽

Peak Displacement

Background: Previous large studies on the effects of cardiac resynchronization therapy (CRT) in patients with heart failure have generally excluded patients previously paced from the right ventricle (RV). Previously RV paced patients (RVp) can exhibit an iatrogenic cause of dyssynchrony and reduced systolic function and thus, may respond differently to CRT than patients not previously RV paced (nRVp). The purpose of this study was to test the hypothesis that RVp patients have greater improvements in left ventricular systolic function, volumes, and dyssynchrony in response to CRT than nRVp. Methods: Standard echocardiograms with tissue Doppler imaging were performed before and after chronic CRT in RVp (n = 21, 16 male) and nRVp (n = 70, 54 male) heart failure patients. Ejection fraction (EF), left ventricular end diastolic (LVEDV) and systolic (LVESV) volumes were calculated using the biplane Simpson’s method. Longitudinal dyssynchrony was calculated as the standard deviation of time to peak displacement (TT-12) of 12 segments in the apical views. Using mid-ventricular short axis views and speckle-tracking methods, radial dyssynchrony (Rad dys ) was calculated as the maximal time difference between six myocardial segments for peak radial strain. Echo response was defined as ≥ 15% reduction in LVESV. Results are reported as mean ± SD. Results: Significant baseline differences (p < 0.05) were observed between groups (RVp vs. nRVp) for age (74 ± 13 vs. 67 ± 13 year), follow-up time (6.1 ± 1.8 vs. 4.6 ± 2.1 months), LVEDV (154.3±50.8 vs.185.3±56.9 mL), and a trend for LVESV (112.4 ± 40.6 vs. 134.9 ± 47 mL, p = 0 .05). No differences were observed for EF, etiology of heart failure, and dyssynchrony measures between groups at baseline. Echo response rate was significantly ( p < 0.05) greater in RVp (76%) than nRVp (57%). After adjusting for baseline differences, RVp had greater improvement in EF (14 ± 9 vs. 8 ± 7%, p < 0.05) and LVESV (−33 ± 18 vs. −20 ± 21%, p < 0.05). After adjustment for follow-up time, no difference was observed for change in dyssynchrony between groups. Conclusion: RVp patients upgraded to CRT exhibit greater improvements in systolic function and ventricular remodeling as compared to nRVp patients.

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