Abstract: A switch for placement in the lead line connecting a pacing pulse generator to an implanted pacing tip electrode in a combined implantable pacing-defibrillation system. The switch is triggered by switch control circuitry to open during defibrillation and to close during pacing. When the switch is open, the implantable unit is electrically isolated from the high voltage defibrillation pulse delivered to the heart. When the switch is closed, a low resistance conduction path is provided in the pacing lead to the pacing tip electrode.

Abstract: An output bridge circuit comprising four independently controlled transistors connected between first and second electrode terminals and a defibrillation capacitor. Two of the four transistors are driven by push-pull driver circuits and connected between the capacitor and the first and second electrode terminals. The remaining two transistors are connected between the first and second electrode terminals and ground terminals. By triggering one of the transistors connected to the push-pull driver circuits and one of the transistors connected between the electrode terminals and the ground terminal, a mono-phasic, multi-phasic, or sequential defibrillation pulse can be generated by activating the appropriate transistors.

Abstract: An output bridge circuit comprising four independently controlled transistors connected between first and second electrode terminals and a defibrillation capacitor. Two of the four transistors are driven by push-pull driver circuits and connected between the capacitor and the first and second electrode terminals. The remaining two transistors are connected between the first and second electrode terminals and ground terminals. By triggering one of the transistors connected to the push-pull driver circuits and one of the transistors connected between the electrode terminals and the ground terminal, a mono-phasic, multi-phasic, or sequential defibrillation pulse can be generated by activating the appropriate transistors.