Triangle ventricular pacing in a non-responder to conventional bi-ventricular pacing.

A 56-year-old man with cardiomyopathy secondary to myotonic dystrophy and complete atrioventricular block presented to our institution. A cardiac resynchronization therapy (CRT) device (InSync 8040, Medtronic, Inc., Minneapolis, MN, USA) was implanted by a conventional bi-ventricular pacing (Bi-V) technique. However, the patient's NYHA class did not improve from class IV despite optimized medical therapy. One month after the CRT device implantation, we altered the pacing configuration from that of Bi-V to 'triangle ventricular pacing' (Tri-V), i.e. conventional Bi-V from the right ventricular (RV) apex and left ventricle plus additional pacing from the RV outflow tract, using a Y connector to bifurcate the RV bipolar output of the device into an anode and a cathode. In both the acute and 3 month follow-up studies, objective parameters revealed better resynchronization effects with Tri-V, and the patient's NYHA class immediately improved to class II. Triangle ventricular pacing may have the potential to decrease the number of non-responders to CRT.