A 67-Year-Old Man With Palpitations During Sleep.

A 67-year-old man with a history of atrial fibrillation (AF) presented to his physician with symptoms of episodic, nighttime palpitations and excessive daytime sleepiness. Four years prior he underwent radiofrequency ablation after a confirmed diagnosis of AF with subsequent resolution of his palpitations. His palpitations returned approximately 1 year following the ablation. These events would occur only at night and awake him from sleep. Holter monitoring showed baseline sinus rhythm with multiple episodes of AF with rates of 75 to 169 beats/min. These events were all nocturnal and correlated with the symptom diary; episodes ranged from 45 min to 2 h. An echocardiogram showed normal left ventricular size and ejection fraction with a mildly enlarged right atrium (4.38 cm) and no evidence of pulmonary hypertension.