[The T-wave shock: a new reliable method for induction of ventricular fibrillation in ICD testing]

During ICD-implantation it is necessary to induce ventricular fibrillation several times to determine the defibrillation threshold. In third generation ICDs there are several options to induce ventricular fibrillation. We want to present a new method, called T-wave-shock, which is first available in the PCD Jewel 7219 (Medtronic). The T-wave-shock is the delivery of a low-energy-shock into the vulnerable period after ventricular stimulation with a basic cycle-length. We applied the T-wave-shock in 46 consecutive ICD-recipients intraoperatively and at the pre-hospital-discharge test. The method is highly effective when applying the shock into the ascending part of the T-wave (98% of the patients were inducible), and the duration of cardial and cerebral ischemia during induction is short (between 3.1 and 3.8 s). This raises defibrillation efficacy.