A patient in their 60s experienced a several-month history of recurrent dizziness and light-headedness. The spells were occasionally preceded by palpitation, nausea, and coning of the visual fields, prompting the patient to sit down. On the day of admission, the patient had an episode of frank syncope resulting in facial contusion. By the time of arrival to the emergency department, full consciousness was regained without postictal symptoms.
On presentation, the heart rate was 88 beats/min and slightly irregular, and the blood pressure was 138/84 mm Hg. Except for obesity and a distant first heart sound, findings of physical examination and results of routine blood tests, including electrolyte, thyrotropin, and cardiac troponin levels, were normal. The 12-lead electrocardiogram (ECG) is presented in the Figure, A. A subsequent echocardiogram showed moderate left ventricular hypertrophy without wall motion abnormalities. All chamber sizes, including the left atrial transverse diameter and left atrial volume index, were within normal limits. The estimated left ventricular ejection fraction was 60% to 65%. Because of dysrhythmia, evaluation of diastolic function was inconclusive.