Right ventricular ejection fraction and left ventricular dyssynchrony by 3D echo correlate with functional impairment in patients with dilated cardiomyopathy.

BACKGROUND: The aim of the study was to detect if right ventricular (RV) ejection fraction assessed by real-time 3-dimensional echocardiography (RT3DE) could predict patients with dilated cardiomyopathy (DCM) with greater functional impairment in response to cardiopulmonary exercise. METHODS AND RESULTS: Seventy chronic heart failure patients with DCM (55.5 ± 9.1 years; 48 males; 30 ischemic; New York Heart Association Class III: 48) underwent both left ventricular (LV) and RV analysis by RT3DE. Postprocessing software provided data of RT3DE systolic dyssynchrony index of 16 LV segments (systolic dyssynchrony index [SDI]) and of both LV and RV ejection fraction. Cardiac magnetic resonance was performed in a subgroup of 40 DCM patients to confirm RT3DE measurements. All the patients underwent also bicycle cardiopulmonary exercise test with evaluation of oxygen consumption (VO2) peak% (percentage of the predicted value), VE/VCO2 slope, and circulatory power (CP). Mean LV ejection fraction was 29.8 ± 4.6%. RT3DE LV SDI index was 8.4.4 ± 4.2, and RV ejection fraction was 51.3 ± 4.6%. By cardiopulmonary test, mean VO2 peak was 15.2 ± 4.4 mL·kg·min, and mean CP was 2.1 ± 0.8. By univariable analyses, significant correlations were detectable between SDI index and VO2 peak% (r = -0.56; P < .0001) and peak CP (r = -0.48; P < .0005). Also RV ejection fraction directly correlated with VO2 peak% (r = 0.58; P < .0001) and inversely with VE/VCO2 slope (r = -0.44; P < .001). By multivariable analysis, SDI index (β coefficient = -0.46; P < .001) and 3D RV ejection fraction (β coefficient = 0.42; P < .001) emerged as the only independent determinants of VO2 peak% during cardiopulmonary test. CONCLUSIONS: Increased LV electromechanical dyssynchrony and impaired RV function in DCM patients are independently associated with worse ability to perform aerobic exercise.