A three-site programmed electrical stimulation protocol in patients with and without ventricular tachyarrhythmias

Programmed electrical stimulation (PES) of the ventricle plays an important role in diagnosis and in testing the effect of pharmacological and non-pharmacological therapy of ventricular tachyarrhythmias. A stimulation protocol should reliably reproduce clinical ventricular tachyarrhythmia. The authors compared the results of the standard one-site protocol to those of a new test delivering extrastimuli alternately into the right and left ventricle. In group I (control group, n = 37), clinically without ventricular tachycardia, tachycardia could not be induced in any of the patients. In group II (n = 30), with clinical ventricular tachycardia, inducibility was in 22 patients using the standard test, and in 23 patients using the new test. The authors conclude that this modification of the PES protocol with alternate extrastimulus delivery into the right and left ventricle does not seem to contribute significantly to PES sensitivity compared to the standard one-site stimulation protocol. It is not clear whether or not another stimulation protocol with alternate stimulus delivery to both ventricles or to different sites in the right ventricle will raise the sensitivity, specificity and reproducibility of the PES test.