Abstract 2939: Short Term Effects of Cardiac Resynchronisation Therapy on Right Ventricular Function
Background: Cardiac resynchronisation therapy (CRT) has been shown to improve left ventricular (LV) function and remodelling in heart failure (HF) patients with prolonged QRS duration. Recently, it has also been demonstrated to reverse the right ventricular (RV) remodelling. However, the effects of CRT on RV function have not been described. Our study aimed to assess the short-term effects of CRT on RV function by analyzing the lateral tricuspid annulus velocities and the lateral RV wall systolic strain .
Methods: Thirty HF patients (NYHA class III or IV, LV ejection fraction (LVEF) 22 ± 7 %, all QRS > 120 ms) were studied before and 3 months after CRT. Mechanical dyssynchrony was measured by the opposing wall delay method. RV chamber size was measured on an apical 4-chamber view by the tricuspid annulus diameter (Tricd), the RV short-axis (RVsa), and the RV long-axis (RVla)dimensions. RV function was assessed with 1) the isovolumic contraction acceleration (IVA) and the peak systolic velocity (S) obtained from the tricuspid annulus velocity traces, and with 2) the systolic strain measured within the basal, mid and apical segments of the RV lateral wall.
Results: Baseline mechanical dyssynchrony was 122 ± 87 ms. At 3 months after CRT, LVEF significantly improved to 27 ± 10 % and LV end-diastolic volumes decreased from 224 ± 71 to 213 ± 63 ml (p < 0.05 vs baseline). At the opposite, RV dimensions did not decrease as demonstrated by the lack of changes in Tricd (3.1 ± 0.7 vs 3.1 ± 0.6; p = 0.74), RVsa (2.9 ± 0.8 vs 2.8 ± 0.9; p = 0.96), and RVla (8.2 ± 1.1 vs 8.1 ± 1.0; p = 0.46). However, S , IVA and basal strain significantly increased after CRT, consistent with an early improvement in RV function (table⇓). Interestingly, this early improvement in RV function was not associated with a decrease in systolic pulmonary pressure (35 ± 11 vs 32 ± 10 mmHg, p = 0,45).
Conclusion: CRT early improves RV function in patients with LV dyssynchrony. This improvement preceedes the RV reverse remodelling.