Abstract 4560: Assessment Of Alterations In Left Ventricular Filling After Reduction Of Right Ventricular Pressure Overload
Background: We have previously shown that reduction in right ventricular (RV) pressures by percutaneous pulmonary valve implantation (PPVI) increases left ventricular (LV) filling. In this study we assessed the impact of septal interaction and inter-ventricular dyssynchrony on LV filling.
Methods: In 18 consecutive patients with pulmonary stenosis (gradient on echocardiography > 50 mmHg) and an indication for PPVI the following were prospectively assessed before and after PPVI: The shape of the septum - evaluated and quantified by calculation of the septal curvature on magnetic resonance (MR) short axis images; LV volumes throughout the cardiac cycle - assessed from an MR short axis stack; and LV to RV delay - derived from time to peak (Tpeak) RV and LV free wall longitudinal strain.
Results: Following PPVI, relief of RV pressure overload resulted in a more favourable septal interaction, as indicated by less leftward bowing of the septum (−0.08±0.10 to +0.06±0.12 cm −1; p<0.001; Fig A⇓). As a consequence of this, there was a significant increase in early LV diastolic filling, as defined by the first third of diastole (19.3±9.1 to 31.0±8.4 ml/m2; p<0.001) and overall LV end-diastolic volumes (74.3±20.7 to 88.7.2±17.7 ml/m2; p<0.001; Fig B⇓). In addition, LV to RV delay improved from 124.3±31.0 to 56.3±36.4 ms (p<0.001), and the change in septal curvature correlated with the change in early diastolic filling (r=0.72, p<0.001) and change in LV to RV delay (r=0.62, p=0.012).
Conclusion: Reduction in RV pressures by PPVI improves early LV filling due to more favourable septal interaction and less LV to RV mechanical dyssynchrony.