Abstract 16998: Ventricular Systolic and Diastolic Dyssynchrony and Their Relationship with Ventricular Function in Patients with Single Ventricular Circulation
BACKGROUND: Recent studies highlighted importance of ventricular diastolic dyssynchrony as well as systolic dyssynchrony in the pathophysiology of adult heart failure. However, little is known about interaction between diastolic and systolic dyssynchrony and their impacts on ventricular function in pediatric patients with single ventricular circulation.
METHODS: We studied 24 pediatric patients (mean age; 2.1±1.3 years) with single ventricular circulation and 12 age-matched control subjects. Transthoracic two-demensional speckle tracking echocardiography (Vivid 7, GE) was performed to assess ventricular dyssynchrony (EchoPac workstation, GE). Systolic and diastolic dyssynchrony was measured as a maximal time delay in peak systolic and early diastolic velocities of longitudinal strain at four segments. Comprehensive ventricular systolic and diastolic function was assessed by employing pressure-area relationships during preload varied by transient inferior vena caval balloon obstruction.
RESULTS: Systolic and diastolic time delay were 31.8±14.5 ms and 29.2±14.6 ms respectively in single ventricular patients, and were significantly larger than in the controls (16.2±11.9 ms for systolic and 15.8±11.2 ms for diastolic, both p<0.01). There was no significant correlation between systolic and diastolic dyssynchrony in the patient group. Systolic dyssynchrony was negatively correlated with ventricular contractility indexes of end-systolic elastance (r=0.34, p<0.05) and maximum rate of pressure rise (r=0.585, p<0.05). Diastolic dyssynchrony was positively correlated with end-diastolic pressure (r=0.719, p<0.05), but not with time constant of ventricular relaxation.
CONCLUSIONS: Not only systolic but also diastolic dyssynchrony has important impacts on ventricular function in patients with single ventricular circulation. These data suggest important notion that diastolic as well as systolic dyssynchrony is an important therapeutic target when considering cardiac resynchronization therapy for patients with single ventricular circulation.
- © 2011 by American Heart Association, Inc.