SHOULD THE PROTOCOL OF PROGRAMMED VENTRIC ULAR STIMULATION BE ADAPTEDFOR EACH PATIENT

The authors report the case of a 56 year old patient in whom the mecha nisms of a wide QRS complex tachycardia recorded on an intensive care monitor could not be determined. The patient also had episodes of atri al flutter with left bundle branch block. Programmed Ventricular stimu lation with 3 extrastimuli triggered a non-specific ventricular flutte r. One week later, the patient was resuscitated from a cardiac arrest which was undocumented. It was therefore important to elucidate the me chanism of the initial tachycardia. A second session of programmed ven tricular stimulation was undertaken. As the use of 2 extrastimuli trig gered runs of unsustained polymorphic ventricular tachycardia, the cla ssical protocol was stopped. An infusion of low-dose isoproterenol was used to repeat programmed stimulation with a single extrastimulus. Th is protocol triggered sustained monomorphic ventricular tachycardia at 240/min. The diagnosis of ventricular tachycardia could therefore be continued.