Sequential transvenous pacing and shock therapy for termination of sustained ventricular tachycardia

Rapid ventricular pacing and transvenous shocks are both effective in terminating sustained ventricular tachycardia (VT) only in selected patients. We prospectively examined efficacy and safety of an algorithm for VT termination combining rapid ventricular pacing with low and moderate energy transvenous shocks in patients with sustained VT. Sixty-three VT episodes in 23 patients, mean age 64 ± 12 years, were treated with the algorithm. Bursts of rapid ventricular pacing and transvenous shocks were delivered with a Medtronic 6880 catheter positioned in the right ventricular apex. VT episodes with cycle lengths >270 msec (group A) were treated with sequential therapy with rapid ventricular pacing (90%, 80%, and 70% of VT cycle length), low energy transvenous shocks (0.5 to 2.7 J), and moderate energy (2.7 to 10 J) transvenous shocks. Rapid VT episodes with cycle lengths 270 msec and can reduce the need for transthoracic cardioversion. Moderate energy transvenous shocks are inadequate to rellably convert rapid VT and frequently result in VT acceleration with the lead employed in this study Alternative electrode configurations need to be evaluated.