Aims This study examined the impact of cardiac resynchronization therapy (CRT) by triangle ventricular pacing (Tri-V) on left ventricular (LV) function and dyssynchrony.
Methods and results Twenty-one patients with NYHA class III or IV heart failure were studied. For Tri-V, two right ventricutar (RV) leads were connected to the CRT device via a Y-connector with one Lead anchored at the RV apex and the other at the RV outflow tract. The W lead was positioned in the posterotaterat or lateral cardiac vein. CRT with standard bi-ventricular pacing (Bi-V) was performed with the RV apical and LV leads. LV function was assessed by the measurement of LV positive dp/dt (dP/dt(max)) and cardiac output (CO). LV dyssynchrony was assessed using the standard deviation of the time to peak myocardial velocity during the systolic phase in 12 LV segments (Ts-SD) derived from tissue Doppler images. In comparison to Bi-V, Tri-V increased dP/dtmax (baseline, 746 +/- 165; Bi-V, 909 +/- 186; Tri-V, 959 +/- 195 mmHg/s, P = 0.04) and CO (baseline, 3.1 +/- 1.0; Bi-V, 3.4 +/- 1.1; Tri-V, 3.8 +/- 1.2 L/min, P < 0.001), decreased Ts-SD (baseline, 54.0 +/- 35.0; Bi-V, 33.6 +/- 15.3; Tri-V, 22.4 +/- 8.1 ms, P = 0.02).
Conclusion The acute beneficial effects of Tri-V on LV function and dyssynchrony were greater than those of Bi-V.