A 30-year-old woman was referred to our hospital to undergo an evaluation for suspected Brugada syndrome. She showed no symptoms, but had a strong family history of sudden cardiac death. During observation, Holter electrocardiography (ECG), which had been performed to investigate her symptoms of occasional dizziness, showed a sinus node dysfunction with an occasional long sinus pause. An implantable cardioverter defibrillator (ICD) was therefore put in place, and bradycardia pacing from the ICD relieved those symptoms during the subsequent 18-month follow-up. The patient completed two pregnancies during the follow-up period. No symptomatic changes occurred during the pregnancies, but ECG indicated that an ST segment elevation in the right precordial leads was attenuated during the second and third trimesters of both pregnancies.