Acute redistribution of regional left ventricular work by cardiac resynchronization therapy determines long-term remodelling

Abstract

Aims Investigating the acute impact of cardiac resynchronization therapy (CRT) on regional myocardial work distribution in the left ventricle (LV) and to which extent it is related to long-term reverse remodelling. Methods and results One hundred and thirty heart failure patients, referred for CRT implantation, were recruited in our prospective multicentre study. Regional myocardial work was calculated from non-invasive segmental stress–strain loop area before and immediately after CRT. The magnitude of volumetric reverse remodelling was determined from the change in LV end-systolic volume, 11 ± 2 months after implantation. CRT caused acute redistribution of myocardial work across the LV, with an increase in septal work, and decrease in LV lateral wall work (all P < 0.05). Amongst all LV walls, the acute change in work in the septum and lateral wall of the four-chamber view correlated best and significantly with volumetric reverse remodelling (r = 0.62, P < 0.0001), with largest change seen in patients with most volumetric reverse remodelling. In multivariate linear regression analysis, including conventional parameters, such as pre-implant QRS morphology and duration, LV ejection fraction, ischaemic origin of cardiomyopathy, and the redistribution of work across the septal and lateral walls, the latter appeared as the strongest determinant of volumetric reverse remodelling after CRT (model R2 = 0.414, P < 0.0001). Conclusion The acute redistribution of regional myocardial work between the septal and lateral wall of the LV is an important determinant of reverse remodelling after CRT implantation. Our data suggest that the treatment of the loading imbalance should, therefore, be the main aim of CRT.

Mechanical Synchrony and Myocardial Work in Heart Failure Patients With Left Bundle Branch Area Pacing and Comparison With Biventricular Pacing

“…Prior to LBBAP, patients had inefficient septal function with markedly low MWE (35.3 ± 17.8%) and high WW (607.1 ± 276.5 mmHg%) compared with global LV (GWE:64.6 ± 7.8%;GWW: 410.3 ± 166.6 mmHg%).Regional analysis of MW revealed that LBBAP leads to significant MWE increases (from 35.3 ± 17.8 to 69.6 ± 19.0%, P = 0.001) and WW reductions (from 607.1 ± 276.5 to 330.8 ± 254.3 mmHg%, < 0.001) in the septum, indicating major improvement in LV function. Reducing septal-lateral work differences in the LV is an important determinant of reverse remodeling after CRT implantation ( 28 , 30 , 31 ). This study showed that LBBAP could reduce the regional differences in myocardial performance between the septal and lateral segments, which leads to more homogeneous regional MW distribution.…”

Acute recoordination rather than functional hemodynamic improvement determines reverse remodelling by cardiac resynchronisation therapy

“…paradoxical) work [ 31 ]. Recently, Duchenne et al demonstrated that acute redistribution of regional LV work, specifically from the lateral wall towards the septum, determined long-term reverse remodelling [ 32 ]. With regional systolic strain representing the main determinant of regional myocardial work in that study, redistribution of work through reversal of wasted work was based on reversal of septal paradoxical stretch also in that study.…”

Myocardial Work: Methodology and Clinical Applications

“…The dyssynchronous ventricular septum produces large amounts of wasted work, and consequently, after response to this treatment, WW reduces and global work index and LV performance increases [8]. A recent study showed that there is acute redistribution of segmental work between septal and lateral work, which is a strong determinant of LV reverse remodeling [28].…”