Cardioversion in Patients with Left Ventricular Thrombus Is Not Associated with Increased Thromboembolic Risk

Objectives: The purpose of the study was to define the incidence of systemic embolism after cardioversion in patients with left ventricular (LV) thrombus. Background: The risk of systemic embolization after cardioversion in patients with an atrial thrombus is well known. However, data on thromboembolic events after cardioversion in patients with LV thrombus are limited because of hesitance to perform cardioversion in this population. Methods: Transthoracic and transesophageal echocardiograms acquired between January 1996 and October 2001 at our institution were reviewed for presence of LV thrombus in two orthogonal apical views. A total of 413 patients had echocardiographic evidence of LV thrombus. Medical records were reviewed for cardioversion performed within 3 weeks of the echocardiogram. Results: A total of 21 patients, age 66 ± 10 years and ejection fraction 22 ± 10% were identified. Cardioversion was indicated for atrial fibrillation in 8 (38%) and ventricular tachyarrhythmia in 13 (62%) patients, and was performed emergently in 5 (24%), electively in 8 (38%), and during electrophysiology study in 8 (38%) patients. The time interval between diagnostic echocardiographic study and cardioversion was 6 ± 5 (range 1-18) days. All thrombi were located in the apical LV and were described as laminated (71%) and protruding (29%), and measured 0.7 ± 0.4 × 1.6 ± 0.8 cm. Before cardioversion, 17 (81%) patients were anticoagulated with warfarin or heparin. During clinical follow-up of up to 1 year (153 ± 150 days) anticoagulation with warfarin was given to 15 (71%) patients. No patient had clinically apparent embolic event, including stroke, during hospitalization or during outpatient follow-up. Conclusions: Embolism after cardioversion in patients with echocardiographic evidence of LV thrombus was not observed. Cardioversion seems to be safe and further prospective studies are needed to address this.