How should I manage a 63-year-old man post-transcatheter aortic-valve replacement who presents with atrial flutter with a ventricular rate of approximately 120 bpm while taking metoprolol tartrate 50 mg twice daily and amiodarone 200 mg daily?

Management of Atrial Flutter with Rapid Ventricular Response Post-TAVR

This patient requires immediate optimization of his rate-control regimen by increasing metoprolol to 100 mg twice daily and continuing amiodarone 200 mg daily, with consideration for electrical cardioversion if rate control remains inadequate or symptoms persist. 1, 2

Immediate Assessment and Rate Control Strategy

Current Medication Adequacy

• The patient's current metoprolol dose (50 mg BID) is subtherapeutic—guideline-recommended dosing for atrial flutter rate control ranges from 25–100 mg twice daily, and this patient is only at the midpoint. 1
• Increase metoprolol tartrate to 100 mg twice daily as the first intervention, as beta-blockers remain first-line for rate control even in post-TAVR patients and provide proven mortality benefit. 1, 2
• The target resting heart rate is 80–110 bpm; a ventricular rate of 120 bpm exceeds this threshold and requires escalation of therapy. 1, 2

Role of Amiodarone

• Continue amiodarone 200 mg daily as it serves dual purposes: rate control augmentation and rhythm maintenance after cardioversion. 1
• Amiodarone at 200 mg daily is effective and associated with fewer side effects than higher doses while maintaining efficacy for atrial flutter suppression. 1
• Do not add additional AV-nodal blocking agents (digoxin, diltiazem) to the combination of metoprolol and amiodarone, as combining more than two such agents substantially increases the risk of severe bradycardia or asystole. 2

Cardioversion Considerations

Anticoagulation Requirements

• Atrial flutter carries the same thromboembolic risk as atrial fibrillation and requires identical anticoagulation protocols before cardioversion. 1
• For atrial flutter of ≥48 hours duration or unknown duration, provide therapeutic anticoagulation for ≥3 weeks before elective cardioversion, or perform transesophageal echocardiography to exclude left-atrial thrombus and proceed if negative. 1, 3
• Continue anticoagulation for at least 4 weeks after cardioversion regardless of whether sinus rhythm is maintained. 1, 3

Cardioversion Strategy

• Electrical cardioversion is recommended when pharmacological rate control does not promptly control the ventricular response or when the patient develops symptoms (dyspnea, chest discomfort, hemodynamic compromise). 1, 3
• Amiodarone pretreatment before scheduled cardioversion improves success rates and prevents immediate recurrence of atrial flutter. 1, 2
• If cardioversion is unsuccessful, repeated attempts may be made after adjusting electrode location or following additional antiarrhythmic medication. 1

Post-TAVR Specific Considerations

Atrial Arrhythmia Burden After TAVR

• Atrial fibrillation and flutter are common after TAVR, with pre-existing AF present in approximately 25% of patients and new-onset AF occurring in 1–8.6% post-procedure. 1, 4
• The presence of atrial arrhythmias after TAVR is associated with prolonged ICU and hospital stays, increased stroke risk, and higher composite adverse event rates. 5, 4
• Subclinical atrial arrhythmias are frequently detected months after hospital discharge and are associated with lack of anticoagulation therapy and increased stroke risk. 5

Antithrombotic Therapy Post-TAVR

• Standard post-TAVR antithrombotic therapy is aspirin 75–100 mg daily lifelong plus clopidogrel 75 mg daily for 3–6 months. 1
• Patients with chronic atrial fibrillation or flutter should receive anticoagulation as per guidelines for AF in patients with prosthetic heart valves—warfarin (INR 2.0–2.5) is preferred over DOACs in the immediate post-TAVR period. 1
• This patient requires long-term anticoagulation given his atrial flutter and post-TAVR status; warfarin should be initiated or continued with target INR 2.0–2.5. 1

Monitoring and Follow-Up

Short-Term Monitoring

• Assess heart rate control during exertion, not just at rest, adjusting pharmacological treatment as necessary. 1
• Obtain ECG at 30 days and annually to monitor for recurrent arrhythmias and conduction abnormalities. 1
• Consider 24-hour Holter monitoring if there is concern for paroxysmal arrhythmias or bradycardia after rate-control medication escalation. 1

Long-Term Management

• The TAVR team should manage the patient for the first 30 days, with formal transfer of care to the primary cardiologist thereafter. 1
• Primary cardiologist follow-up at 6 months and then annually is recommended for stable patients without complications. 1
• Echocardiography at 30 days and then annually to monitor prosthetic valve function and exclude paravalvular regurgitation. 1

Critical Pitfalls to Avoid

• Never use AV-nodal blockers in pre-excited atrial flutter (Wolff-Parkinson-White pattern on ECG), as they can precipitate ventricular fibrillation. 1, 2
• Do not combine more than two AV-nodal blocking agents (beta-blocker, digoxin, amiodarone) due to risk of severe bradycardia or asystole. 2
• Avoid nondihydropyridine calcium-channel blockers (diltiazem, verapamil) if the patient has decompensated heart failure or reduced ejection fraction. 1
• Do not discontinue anticoagulation after successful cardioversion based solely on rhythm status—continuation depends on thromboembolic risk (CHA₂DS₂-VASc score). 1, 3
• Electrical cardioversion is contraindicated in the presence of digitalis toxicity or significant hypokalemia. 3