Electrocardiographical case. Young woman with frequent syncope attacks.

A 29-year-old woman with frequent syncope attacks was referred for electrophysiological study and consideration for radio-frequency ablation of her ventricular arrhythmias. Her ECG showed features of right ventricular outflow tract premature contraction. Differential diagnoses for the causes of syncope in this patient include: right ventricular outflow tract tachycardia, arrythmogenic right ventricular dysplasia, and neurocardiogenic syncope. She underwent a tilt table test, which showed a malignant cardioinhibitory response. She developed abrupt syncope with 32 seconds of asystole during the test. She was given intravenous atropine and was resuscitated. A dual chamber rate-responsive pacemaker was implanted for her the next day. She was discharged well subsequently. Although the prognosis in patients with prolonged aystole in malignant vasovagal syncope is unknown, most doctors will still choose to implant a permanent pacemaker for patients with malignant neurocardiogenic syncope when the sinus arrest is prolonged.