A Stunning Left Atrial Appendage Thrombus.
BACKGROUND
Left atrial appendage thrombus formation is a known major complication of atrial fibrillation and atrial flutter which increases the risk of embolism and stroke. This risk of thrombosis is greatly increased with a lack of anticoagulation. After conversion to a normal sinus rhythm in these arrhythmias, the risk of thrombus formation in the left atrium persists through a phenomenon termed atrial myocardial stunning.


METHODS
We present the case of a patient who previously underwent successful pulmonary vein isolation and was found to be in typical isthmus-dependent atrial flutter with a questionable recurrence of atrial fibrillation. The decision was made to return for atrial flutter ablation and for evaluation of prior pulmonary vein isolation. Initially, a transesophageal echocardiogram showed a normal ejection fraction, biatrial enlargement and no left atrial appendage thrombus. Ablation of the cavotricuspid isthmus was successfully accomplished with documented bidirectional block. A transesophageal echocardiogram probe was still in place prior to planned transseptal puncture for the evaluation of pulmonary veins. A large thrombus was now observed filling the left atrial appendage. Conclusion and Objective: Atrial stunning is a transient atrial contractile dysfunction that occurs whether sinus rhythm is restored spontaneously, electrically, pharmacologically or by ablation. We know after conversion that there is higher propensity to increased spontaneous echogenic contrast and decreased velocities; however, we do not have documented knowledge of exactly how soon after the conversion to a sinus rhythm a thrombus may be seen. We demonstrate a case of acute left atrial appendage thrombus formation immediately following the successful ablation of isthmus-dependent atrial flutter. Our report validates the belief that strategies of not interrupting anticoagulation prior to the conversion of these arrhythmias should be implemented.
Mercy St. Vincent Hospital and Medical Center, Toledo, Ohio, USA.
Sajid
S
Ali
Justin
J
Ugwu
Yousuf
Y
Kanjwal
D000368:Aged; D020517:Atrial Appendage / Q000000981:diagnostic imaging / Q000503:physiopathology; D001282:Atrial Flutter / Q000150:complications / Q000175:diagnosis / Q000601:surgery; D016279:Atrial Function, Left; D017115:Catheter Ablation / Q000379:methods*; D017548:Echocardiography, Transesophageal / Q000379:methods; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods; D017984:Enoxaparin / Q000008:administration & dosage*; D005343:Fibrinolytic Agents / Q000008:administration & dosage; D006325:Heart Atria / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D008297:Male; D017682:Myocardial Stunning / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D013927:Thrombosis / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology / Q000503:physiopathology; D016896:Treatment Outcome
D017984:Enoxaparin; D005343:Fibrinolytic Agents