PC-based cardiac electrophysiological studies: a pacing system with real-time screen monitoring of endocardial electrograms

Programmed electrical stimulation is an important clinical procedure in the assessment of bradycardias and ventricular tachycardias. The standard instrumentation involved in this procedure is costly and limited in the aspects of intelligent interpretation of ECG events, real-time display and storage, including pre-events, and at the same time of being user friendly. The authors have developed a PC-based pacing system capable of delivering the required stimulation protocols used in standard cardiac electrophysiological studies (EPS), with the extra facility of real-time screen display of the endocardial electrogram seen at the transvenous catheter electrodes. On the patient side, the system consists of an electrically isolated interface module with a regulated pulse driver and an ECG sensing circuitry, both sharing a common pair of catheter terminals. At the computer side, a special software environment has been developed for easy interactive programming of the stimulation protocols, and real-time ECG processing and display (30% of the screen). The developed PC-bused system was tested during 4 complete EPS procedures in 4 different patients.