Evaluation and management of a supraventricular tachycardia with a standard bradycardia support pacemaker.

A standard dual chamber pacemaker with the ability to telemeter intracardiac electrograms and to perform noninvasive electrophysiological studies was implanted in a patient with previously documented complex ventricular arrhythmias treated with amiodarone who later presented with a hypersensitive carotid sinus syndrome and syncope. Subsequently, he developed a supraventricular tachyarrhythmia with an atrial cycle length of 320 ms. Its diagnosis was facilitated by the ability to noninvasively telemeter atrial endocardial electrograms directly from the implanted pacemaker. Its management was aided by utilizing the already implanted bradycardia support pacemaker to stimulate the patient with premature extrastimuli coupled to his intrinsic atrial rhythm (PS1 and S1S2 each 170 ms.) by connecting the pacemaker to an electrophysiological stimulator via the pacemaker programmer. This particular pacemaker was not chosen because of this capability at the time of its original implantation. However, this capability facilitated the patient's evaluation and subsequent management.