Effect of triangle ventricular pacing on haemodynamics and dyssynchrony in patients with advanced heart failure: a comparison study with conventional bi-ventricular pacing therapy.

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 ventricular (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 LV lead was positioned in the posterolateral 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/dt(max) (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.