Severe Left Atrial Appendage Stunning After Electrical Cardioversion of Atrial Fibrillation
A 77-year-old man with a history of ischemic cardiomyopathy presented with 3 days of progressively worsening dyspnea. An ECG revealed atrial fibrillation at a rate of 97 bpm. An echocardiogram showed severe left atrial enlargement, severely elevated left ventricular filling pressure, and an ejection fraction of 30%. Thyroid function studies were normal. His symptoms of dyspnea improved modestly with intravenous diuresis. A transesophageal-guided cardioversion was performed to restore atrial systole. The patient was concurrently enrolled in a research study designed to assess left atrial appendage (LAA) stunning after electric cardioversion of atrial fibrillation. After electrical cardioversion, LAA velocities were markedly reduced, and a de novo 1.14×1.17-cm mobile thrombus was detected in the LAA consistent with severe LAA stunning (Figure and online-only Data Supplement movies). The phenomenon of atrial stunning is thought to occur in most patients after cardioversion of atrial fibrillation,1,2 underscoring the importance of anticoagulation in the immediate postcardioversion period to reduce the risk of thromboembolic events.3
We acknowledge Mark Zangs for his expert technical assistance.
The online-only Data Supplement is available with this article at http://circ.ahajournals.org/cgi/content/full/118/21/e699/DC1.
Melduni RM, Malouf JF, Chandrasekaran K, Bruce CJ, White RD, Law KK, Al Atawi FO, Somers VK, Gersh BJ, Hodge DO, Friedman PA, Seward JB, Ammash NM. New insights into the predictors of left atrial stunning after successful direct-current cardioversion of atrial fibrillation and flutter. J Am Soc Echocardiogr. 2008; 21: 848–854.