A 53-year-old housewife was seen because of a recent onset of palpitations and dyspnea on exertion; she had a history of heart murmur for 20 years. On physical examination, the patient was acyanotic and jugular venous pulses showed prominent and equal a and v waves; a left parasternal impulse was present. Auscultation revealed a pulmonary ejection sound followed by a midfrequency systolic ejection murmur at the second left intercostal space. Splitting of S2 was wide and fixed, with accentuation of pulmonic closure. An S3 was present at the fourth left intercostal space. Electrocardiogram showed atrial fibrillation and right axis deviation with right ventricular hypertrophy. A chest x-ray film revealed cardiomegaly and prominent pulmonary vascular markings with a prominent pulmonary artery. Her echocardiogram is shown in the Figure; the bold time lines at the top of the tracing are 0.2 second; the vertical dot intervals are 1.0 cm.