Diastolic Asynchrony Is More Frequent Than Systolic Asynchrony in Dilated Cardiomyopathy and Is Less Improved by Cardiac Resynchronization Therapy

Abstract

Diastolic asynchrony is weakly correlated with QRS duration, is more frequent than systolic asynchrony, and may be observed alone. Diastolic asynchrony is less improved by CRT than systolic. Persistent diastolic asynchrony may explain some cases of lack of improvement after CRT despite good systolic resynchronization.

Left Ventricular Diastolic Mechanical Dyssynchrony and Associated Clinical Outcomes in Children With Dilated Cardiomyopathy

“…13 Although the bulk of research both in adults 1,2,14 -16 and in children 3,17 relating to mechanical dyssynchrony has focused on systolic wall motion, recent findings indicate that diastolic wall-motion abnormalities are prevalent in adults with heart failure, both with and without systolic dysfunction. 6,8,9 The present study is the first to investigate diastolic mechanical dyssynchrony in children with DCM and the first to explore its relation to clinical status in this group of patients. The major findings of the present study were as follows: (1) LV diastolic wall motion is highly synchronized in normal children; (2) LV intraventricular diastolic mechanical dyssynchrony is common in pediatric DCM; (3) an intraventricular diastolic dyssynchrony index of 17 ms is a reasonable threshold to define the presence of diastolic mechanical dyssynchrony in children; and (4) DCM patients with worse transplant-free survival have more diastolic dyssynchrony and conversely, those with diastolic dyssynchrony appear to have a worse survival than patients without diastolic dyssynchrony.…”

“…Wang et al 8 found that medical therapy, including diuretics, ␤-blockers, calcium channel blockers, and angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, improved diastolic dyssynchrony in adults with cardiomyopathy and decreased filling pressures, but they did not investigate which of these medications brought about these changes. Schuster et al 6 found in adults that cardiac resynchronization therapy reduced diastolic dyssynchrony, albeit with lesser effect than systolic dyssynchrony. Others have found that pacing improves diastolic ventricular-ventricular interactions.…”

Cellular and Molecular Aspects of Dyssynchrony and Resynchronization

“…Diseases of the conducting system such as a left-bundle branch block (LBBB) leads to a loss of synchrony, and occurs in 30-50% of patients with dilated cardiomyopathy [1,2]. As a result, regions of the heart stimulated early will contract sooner and at reduced load [3], and rather than generating sufficient pressure to open the aortic valve and eject blood, they impart energy to stretch the later-activated regions.…”

Impact of antihypertensive treatment on left ventricular systolic dyssynchrony in treatment-naïve hypertensive patients

“…Pulsed-TDI of the four sides of the mitral annulus (septal, lateral, inferior and anterior) was also obtained in 4-and 2-chamber views to assess global cardiac function. 16,17 (4) The subaortic flow velocity was obtained by pulsed-wave Doppler from the apical 5-chamber view. The LV ejection time was measured as the interval between the onset of forward aortic flow and the aortic valve closure artifact.…”

“…1 There has been increased recognition that LV dyssynchrony also exists in patients without HF but with other cardiac diseases, including hypertension, 2 coronary artery disease (CAD) 3 and cardiomyopathy. 4,5 Dyssynchrony has been measured using a variety of echocardiographic parameters based on different imaging techniques, 6 including pulsed-wave tissue Doppler imaging (TDI), colorcoded TDI, tissue tracking, displacement mapping, strain and strain rate imaging, and tissue synchronization imaging. TDI is the most extensively tested method.…”