Electrocardiographic and electrophysiologic findings in Ebstein's anomaly: Pathophysiology, diagnosis, and management

Abstract

In 1866, Dr. Wilhelm Ebstein described the postmortem findings of severe malformation of the tricuspid valve and a patent foramen ovale in a patient with a history of cyanosis, dyspnea, and palpitations.’ Since that initial description, the tendency for palpitations, tachycardia, and occasionally sudden death to develop in patients with Ebstein’s anomaly of the tricuspid valve has been recognized.2-10 Furthermore, the important association between preexcitation and Ebstein’s anomaly has been established. Patients with Ebstein’s anomaly are predisposed to arrhythmias because of abnormal cardiac anatomy, and they tend to decompensate hemodynamitally when an arrhythmia occurs. Tachyarrhythmias are poorly tolerated in the setting of right ventricular dysfunction, tricuspid insufficiency, and an atria1 septal defect, resulting in increased right-to-left shunting, hypoxemia, and reduced cardiac output.8u Consequently, anatomic and electrophysiologic abnormalities in Ebstein’s anomaly are interrelated determinants of hemodynamic severity and clinical course. Following is a review of the unique pathologic, electrocardiographic, and electrophysiologic features of Ebstein’s anomaly that predispose patients