From the Guidelines
Pre, intra, and post-operative care for a patient undergoing transesophageal echocardiogram (TEE) guided cardioversion involves specific protocols at each stage, with a focus on minimizing thromboembolic risk and ensuring patient safety, as recommended by the 2024 ESC guidelines for the management of atrial fibrillation 1.
Pre-Operative Care
Pre-operatively, patients should fast for at least 6 hours before the procedure to reduce aspiration risk. Anticoagulation status must be verified, with patients typically requiring therapeutic anticoagulation for at least 3 weeks prior to elective cardioversion, or a negative TEE to rule out left atrial thrombus, as suggested by the Chest guideline and expert panel report 1. Medications like digoxin should be continued, but insulin doses may need adjustment due to fasting. A thorough history and physical examination should be performed, with particular attention to airway assessment and dental status.
Intra-Operative Care
Intra-operatively, the patient receives conscious sedation typically using midazolam (1-2mg IV) and fentanyl (50-100mcg IV), titrated to effect. Continuous monitoring of vital signs, oxygen saturation, and cardiac rhythm is essential. The TEE probe is inserted to evaluate for atrial thrombi before delivering synchronized electrical cardioversion, usually starting at 100-200 joules biphasic (or 200 joules monophasic). Direct oral anticoagulants (DOACs) are recommended in preference to vitamin K antagonists (VKAs) in eligible patients with atrial fibrillation undergoing cardioversion for thromboembolic risk reduction, as stated in the 2024 ESC guidelines 1.
Post-Operative Care
Post-operatively, patients require monitoring until fully recovered from sedation, typically 1-2 hours. They should not eat or drink until the gag reflex returns, usually within 1-2 hours. Anticoagulation must be continued for at least 4 weeks post-procedure (longer for patients with risk factors), as recommended by the Chest guideline and expert panel report 1. Patients should be educated about potential complications including sore throat, bleeding, or signs of stroke, and instructed to seek immediate medical attention if these occur. The use of NOACs, such as dabigatran, rivaroxaban, edoxaban, or apixaban, is supported by evidence from studies, including the antithrombotic therapy for atrial fibrillation: Chest guideline and expert panel report 1 and the 2024 ESC guidelines for the management of atrial fibrillation 1.
Some key points to consider:
- The TEE-guided approach can be used to avoid prolonged anticoagulation before cardioversion, but requires an experienced echocardiographer and careful patient selection, as noted in the antithrombotic therapy for atrial fibrillation: Chest guideline and expert panel report 1.
- The NOACs offer an alternative to VKAs in the setting of cardioversion, with comparable efficacy and safety, as shown in studies, including the antithrombotic therapy for atrial fibrillation: Chest guideline and expert panel report 1.
- A risk-based approach to anticoagulation should be used, taking into account the patient's individual risk factors for stroke and bleeding, as recommended by the 2024 ESC guidelines for the management of atrial fibrillation 1.
From the Research
Pre-Operative Care Protocols
- Patients with atrial fibrillation (AF) of > 48 h or of unknown duration for whom pharmacologic or electrical cardioversion is planned should receive anticoagulation with an oral vitamin K antagonist (VKA), such as warfarin, for 3 weeks before elective cardioversion and for at least 4 weeks after sinus rhythm has been maintained 2.
- A screening multiplane transesophageal echocardiography (TEE) should be performed to check for thrombus before cardioversion 2.
- Patients with AF of known duration < 48 h can undergo cardioversion without prolonged anticoagulation, but IV heparin or low-molecular-weight heparin (LMWH) can be started at presentation 2.
- The CHA2DS2-VASc score can be used to estimate the risk of left atrial appendage thrombus (LAAT) formation, with a score ≥ 3 points indicating a higher risk 3.
Intra-Operative Care Protocols
- TEE-guided cardioversion can be performed using low molecular weight heparin (LMWH) as an anticoagulant, with warfarin therapy continued after the procedure 4.
- The use of TEE can help identify patients with left atrial thrombus or spontaneous echocontrast, who may require postponement of cardioversion or alternative treatment strategies 5, 6.
- Cardioversion can be performed immediately after TEE if no thrombus is seen, and anticoagulation can be continued for at least 4 weeks after sinus rhythm has been maintained 2.
Post-Operative Care Protocols
- After successful cardioversion, anticoagulation with an oral VKA, such as warfarin, should be continued for at least 4 weeks 2.
- A second TEE can be performed 7 days after cardioversion to check for atrial stunning and thrombus formation, and anticoagulation can be terminated if no signs of stunning are present 6.
- Patients who undergo TEE-guided cardioversion with LMWH can have a shorter period of anticoagulation, with a mean duration of 8.5 days 6.
- The risk of thromboembolic events and bleeding complications should be monitored closely after cardioversion, with adjustments to anticoagulation therapy as needed 4.