Related Experiment Video
Updated: Jul 1, 2025
The WATCHMAN Left Atrial Appendage Closure Device for Atrial Fibrillation
Published on: February 28, 2012
A case report of postcardioversion device-related thrombus in a patient with left atrial appendage occlusion device
Hasaan Ahmed1, Mahmoud Ismayl2, Anirudh Palicherla1
1Department of Medicine, Division of Internal Medicine.
Insights
Transesophageal echocardiography (TEE) may be necessary before repeat cardioversion, even in patients on anticoagulation. A case revealed a new thrombus in a patient with atrial fibrillation and a left atrial appendage occlusion device, highlighting risks beyond current guidelines.
Area of Science:
- Cardiology
- Electrophysiology
- Medical Devices
Background:
- Current guidelines suggest cardioversion without routine preprocedural transesophageal echocardiography (TEE) for patients on anticoagulation.
- The efficacy of these guidelines for repeat cardioversion is not well-established.
Observation:
- A 66-year-old male with atrial fibrillation (AF) and a left atrial appendage occlusion (LAAO) device developed a new left atrial thrombus.
- This occurred despite being compliant with anticoagulation and having a prior unremarkable TEE before an initial cardioversion.
Findings:
- The patient's TEE revealed a new 2 cm x 1 cm thrombus in the left atrium, above the WATCHMAN device.
- This finding led to the cancellation of a scheduled repeat cardioversion.
Implications:
- Anticoagulation may not fully mitigate thrombus risk in patients with stroke risk factors or LAAO devices.
- Further research is needed to determine the necessity of routine TEE after cardioversion in high-risk patients.
Background:
Current guidelines recommend proceeding with cardioversion, without the explicit need for preprocedural transesophageal echocardiography (TEE), in patients compliant with oral anticoagulation for at least 3 weeks. The relevance of these guidelines remains unclear in those undergoing repeat cardioversion.
Case Summary:
A 66-year-old male with a history of atrial fibrillation (AF) and a left atrial appendage occlusion (LAAO) device, compliant with apixaban, presented with dyspnea and lightheadedness. He was cardioverted into sinus rhythm, 10 days before symptom onset, with TEE unremarkable at the time. An ECG revealed that the patient converted back into AF and a repeat cardioversion was scheduled. At the patient's request, a TEE was obtained, revealing a new 2 cm×1 cm thrombus in the left atrium above the WATCHMAN device. Cardioversion was canceled and the patient was hospitalized for AF management.
Discussion:
Cardioverted patients are at risk for thrombus formation due to atrial stunning, a transitory dysfunction of the atrial appendage and atrium, which occurs immediately after cardioversion and can persist for several weeks. The likelihood of a thrombus is further propagated by individual risk factors for stroke.
Conclusion:
Anticoagulation does not eliminate the risk of thrombus formation in those with increased risk factors for stroke. Further studies are warranted to assess the need for routine TEE, after cardioversion, in those with stroke risk factors on anticoagulation or who have LAAO.
