Interface module for regulated current pulse delivery in gastro-thoracic stimulation

Conventional electrophysiological study of the heart requires very low energy stimulation pulses but, transvenous catherisation and access to x-ray fluoroscopy, are necessary for this clinical procedure. An interface module was developed in order to implement Gastro-thoracic stimulation (GTS) of the ventricles, which is a non-invasive alternative but which requires higher energy stimulation pulses. The interface module allows the use of a conventional universal stimulator to perform GTS, transparently, as if the patient and catheter were connected directly to the universal stimulator. The interface module was tested clinically in 12 patients in which the conventional invasive method and GTS were practiced for ventricular tachycardia inducibility. This paper describes the interface module and presents the results obtained in the clinical trial. Results, as presented for 12 patients comparing catheterisation and GTS, show agreement in 6 patients being inducible and 4 not inducible. There was one false positive and one false negative.