Abstract 21199: Left Ventricular Systolic Dyssynchrony; Prevalence and Determinants in a Population-Based Cohort
Background: Left ventricular (LV) systolic dyssynchrony, quantified by the standard deviation of time-to-peak systolic myocardial velocity (Ts-SD), has been shown to be prevalent in various clinical and subclinical cardiac diseases. An evaluation of the determinants of LV dyssynchrony in unselected populations is likely to facilitate a better understanding of the pathophysiology and natural history of LV dysfunction.
Aim: To assess the prevalence and clinical/echocardiographic determinants of LV systolic dyssynchrony in a population-based sample of older adults.
Methods: Cardiac structure and function was assessed by echocardiography in the first 451 participants of a prospective population-based cohort study (mean age 75.3±5.9yrs, 49% men). LV systolic synchrony was quantitated as Ts-SD, and measured as the time from QRS-onset to peak systolic velocity at 6 basal segments in the apical views.
Results: Of the 451 subjects (mean Ts-SD: 46±26ms), 311 (69%) had LV systolic dyssynchrony, previously defined as Ts-SD>30ms. Ts-SD was higher in women (50±24ms vs. 41±26ms; p=0.0003). Clinical correlates of Ts-SD included a history of systemic hypertension; systolic blood pressure and pulse pressure; increased heart rate; and body mass index (Table). Ts-SD increased with LV total systolic period, LV end-diastolic size; LV mass index; and LV filling pressure as assessed by E/e'. In multivariable analysis, independent predictors of Ts-SD included sex, heart rate, pulse pressure, and LV filling pressure (all p<0.05).
Conclusions: In an unselected population of older adults, LV systolic dyssynchrony, as assessed by Ts-SD, is highly prevalent and is determined by factors related to LV afterload, total systolic time, and intrinsic properties of LV structure and diastolic function.
- © 2010 by American Heart Association, Inc.