Diastolic myocardial mechanics and their relation to ventricular filling pressures and post-operative course in functionally single ventricles.

Abstract

Diastolic dysfunction affects outcomes in patients with functionally single ventricles (FSV). To study the association of ventricular mechanics and interventricular dependence on diastolic parameters and early post-Fontan outcomes. Sixty-one FSV patients underwent echocardiography, cardiac catheterization and magnetic resonance imaging on the same day before or after the Fontan procedure. Echocardiographic diastolic parameters, ventricular mass and incoordinate wall motion, defined by the number of dyskinetic segments or by the lateral wall delay, were determined and studied for relationships with invasively measured hemodynamics and early post-operative Fontan course. In subjects with a sizable secondary ventricle, incoordinate motion was additionally analyzed at the left and right sided ventricular free-walls. Resting ventricular end diastolic pressure (VEDP) was ≤10 mmHg in most subjects. Echocardiographic parameters of diastolic flow and tissue velocities did not correlate with VEDP or post-Fontan clinical course. Incoordinate wall motion in the dominant and sizeable secondary ventricle, defined by the lateral wall delay or by the number of dyskinetic segments, was the only echo parameter correlating, albeit weakly, with VEDP (r=0.247, p=0.040), oxygen saturation (r=-0.417, p=0.001), pulmonary vascular resistance and flow (Qp) (r=-0.303, P=0.011) and duration of endotracheal intubation (r =0.292, p=0.022). When incoordinate wall motion was analyzed in the secondary ventricle these associations strengthened. The degree of diastolic incoordinate ventricular wall motion was associated with VEDP and post-operative Fontan course. Analysis of incoordinate wall motion of the dominant and sizeable secondary ventricle should be included in the assessment of the FSV after Fontan .