Computer mapping of ventricular tachyarrhythmias during cardiac surgery

Sustained ventricular tachyarrhythmias are life-threatening events, which in about one half of the cases are refractory to medical therapy. In those patients cardiac surgery with aneurysmectomy and endocardial resection offers a curative approach, if the origin of ventricular tachycardia can be identified by mapping procedures. The authors therefore developed a mapping system, which allows one to record 256 channels simultaneously. The input amplifiers have been designed to record from a high impedance source with low voltage output in the noisy environment of the operating theatre. The amplifiers are DC-shock proved, electrically uncoupled by isolation amplifiers, and allow unipolar or bipolar recording of signals. Multi-site stimulation is possible from any amplifier input controlled by the computer. The computer mapping system allows fast and accurate determination of the site of origin of ventricular tachycardia even if only short runs of tachycardia are inducible by ventricular stimulation.