Acute Modifications of Left Ventricular Torsional Mechanics Induced by Cardiac Resynchronization Therapy Affect Short-Term Reverse Remodeling

Abstract

Background: Left ventricular (LV) torsion is an important aspect of cardiac mechanics and is altered in heart failure patients. Cardiac resynchronization therapy (CRT) has a positive effect on LV function, but the exact mechanisms through which it works are not completely depicted. Our aim was to investigate (1) the acute CRT effect on LV torsional mechanics in heart failure patients using 3D speckle tracking echocardiography (3DSTE) and (2) its effect on short-term LV remodeling. Methods and Results:We considered 48 patients (age 72±11 years, 35 men) who received CRT. They underwent 3DSTE during CRT-on (biventricular stimulation) vs. CRT-off (intrinsic conduction/right atrial/ventricular stimulation alone), in a random fashion. Patients were classified as CRT responders based on LV systolic volume reduction ≥15% at 6 months (final population: 31 responders, 17 non-responders). Acute CRT positively affected responders in terms of LV torsion (from 0.32±0.06°/cm CRT-off to 0.41±0.06°/cm CRT-on), but adversely affected non-responders (from 0.54±0.08°/cm CRT-off to 0.28±0.08°/cm CRT-on, interaction P=0.02). A similar trend was confirmed for apical (interaction P<0.04), but not for basal torsion (interaction P=0.351). Conclusions:CRT has a positive role in acute recovery of LV torsion (particularly in its apical component) in responders, likely modulating the improvement in LV remodeling at early follow-up.

The implementation of speckle tracking echocardiography for cardiac resynchronization therapy optimization. A rotational myocardial mechanics interpretation

“…However, it is still uncertain what is the best echocardiographic index of cardiac asynchrony, although recently STE and 3D echocardiography have provided reliable and more predictive data than those used prior to these innovative imaging modalities (16). LV myocardial torsional mechanics are known to be compromised in HF patients (17,18,19), though an increasing interest for its role in assessing improvement to CRT is recently noticed (20). The reasons of this investigating hesitancy might be the low reproducibility of measurements, the complex helical ventricular architecture and contraction and the different vectors' software tools that frequently provide contradictory data of identical phenomena.…”

Left ventricular systolic motion pattern differs among patients with left bundle branch block patterns

“…The LV twist is a sensitive indicator of LV systolic function, which has been established in various populations with multifarious diseases [11][12][13][14] . Heart failure patients scheduled for cardiac resynchronization therapy (CRT) were prospectively studied by Chiara et al [15] . They found that alterations in LV twist take place earlier than variations in LV volumes and LVEF.…”

123 I-MIBG scintigraphy in the assessment of heart failure prognosis and effectiveness of cardiac resynchronization therapy

“…Особое внимание было уделено методам лучевой диагностики для определения групп пациентов, у которых СРТ будет эффективна [25][26][27]. В ряде работ была показана возможность методов сердечно-сосудистой визуализации выделять пациентов с наибольшей вероятностью обратного ремоделирования ЛЖ через 6 месяцев после СРТ [28][29][30]. В то же время необходимо отметить, что у некоторых пациентов обратное ремоделирование происходит в более поздние сроки [31,32].…”