This 38-year-old man was brought to the Emergency Department after an episode of syncope.

During the previous night, when getting up to urinate he felt transiently dizzy. He returned to bed, and and promptly his symptoms improved. On the way to work in the morning while standing in a subway car, he felt hot, lightheaded, nauseated, and proceeded to faint. Upon collapsing to the floor, he recovered consciousness immediately:

• Sinus rhythm, 87/min
• Incomplete right bundle branch block (iRBBB)
• Prominent coved ST elevation in V1-V2 compatible with type 1 Brugada ECG pattern

The patient was admitted to hospital and monitored. He remained symptom-free and had no arrhythmias. The history was suggestive of a vasovagal episode. A head-up tilt test was positive. An echocardiogram and an MRI were obtained to rule out associated arrhythmogenic right ventricular dysplasia (ARVD) were normal. There was no family history of syncope, arrhythmias, or sudden death.

The episode of syncope was most likely vasovagal. It was felt, however, that an electrophysiologic study was indicated to investigate whether a ventricular arrhythmias could be induced. The patient was readmitted for EP testing 2 months later. He reported that in the interval, he had remained symptom-free.

With electrical stimulation at base cycle length of 400 milliseconds and double extra-stimuli at 230 and 220 milliseconds, a run of polymorphic ventricular tachycardia was induced. The arrhythmia was not terminated by a 360 Joules shock, however, it resolved spontaneously. The following tracings document the onset and end of the ventricular arrhythmia:

The results of the investigation were discussed with the patient. The symptoms during the ventricular arrhythmia were quite different from those he had experienced at the time of his episode of syncope, which was most likely vasovagal in nature. In view of the   positive electrophysiologic study,  he was offered the option of receiving an implantable defibrillator (ICD). The patient decided in favor of conservative management, and refused the ICD.