Post-cardioversion ST-segment elevation: a case-based review of the pathophysiology

A 69-year-old woman with mitral regurgitation, diabetes, hyperlipidemia, and recurrent persistent atrial fibrillation (AF) was referred to the electrophysiology laboratory for transesophageal echocardiogram (TEE) and synchronized direct current cardioversion (DCCV). She was anticoagulated with warfarin for a CHADS2-Vasc score of 4. The remainder of her medication regimen included amiodarone, insulin, and atorvastatin. A recent coronary angiogram revealed no significant coronary artery disease. Baseline electrocardiogram (ECG) revealed AF, at a ventricular rate of 100 beats per minute, left axis deviation, and non-specific T-wave abnormalities ( Figure 1 ). Cardioversion pads were placed in the anterior-posterior position. The TEE revealed normal function, mitral regurgitation, left atrial enlargement, and reduced left atrial appendage emptying velocity. There was no evidence of thrombus present. The patient then underwent DCCV with delivery of a single 200 joule biphasic shock.