Development of left atrial thrombus and subsequent cardioembolic stroke in a 21-year-old man with ebstein anomaly who previously underwent pulmonary vein isolation ablation and Cox maze III procedure: significance of left atrial mechanical function

Information about a real patient is presented in stages (boldface type) to an expert clinician (Dr Ammash), who responds to the information, sharing his reasoning with the reader (regular type). A discussion by the authors follows. A 21-year-old man with a history of Ebstein anomaly and atrial fibrillation who had previously undergone tricuspid valve repair, pulmonary venous isolation, and the Cox maze III procedure was referred from an outside institution for the evaluation of an acute onset of left-sided upper- and lower-extremity weakness. The patient had initially presented 3 years earlier with abdominal pain and symptomatic palpitations. Physical examination at that time revealed a jugular venous pressure of 12 cm without a prominent V wave. Cardiac palpation noted a sternal heave. On auscultation, a grade II holosystolic murmur was appreciated at the left sternal border that increased with inspiration. Abdominal inspection noted an enlarged liver that was not pulsatile. A standard 12-lead ECG demonstrated sinus rhythm with first-degree atrioventricular block(Figure 1), and a chest x-ray noted enlargement of the right atrium(Figure 2). A 24-hour Holter monitor noted that the predominant rhythm was atrial fibrillation interrupted by brief periods of sinus rhythm. Transthoracic echocardiography demonstrated severe right atrial enlargement, dilatation of the tricuspid annulus, apical displacement of the tricuspid valve (displacement index, 10.2 mm/m2), large anterior tricuspid valve leaflet, and severe tricuspid regurgitation consistent with Ebstein anomaly. Figure 1. Resting 12-lead ECG demonstrating sinus rhythm with first-degree atrioventricular block and nonspecific T-wave abnormalities. Figure 2. Patient chest x-ray demonstrated enlargement of the cardiac silhouette, particularly the right atrium (arrow). Dr Ammash: Ebstein anomaly is a rare disorder accounting for