What is the management of atrial fibrillation (AF) in patients with rheumatic heart disease (RHD), considering scenarios with fast ventricular response (FVR) versus controlled ventricular response (CVR), hemodynamically stable versus unstable status, and acute versus chronic persistent AF?

Management of Atrial Fibrillation in Rheumatic Heart Disease

Hemodynamically Unstable AF (Regardless of Acute vs Chronic)

Immediate electrical cardioversion is mandatory for hemodynamically unstable patients with AF causing symptomatic hypotension, angina, myocardial infarction, shock, or pulmonary edema, without waiting for prior anticoagulation. 1

• Administer heparin concurrently by initial intravenous bolus followed by continuous infusion (aPTT 1.5-2 times control) immediately after cardioversion 1
• Follow with oral anticoagulation (INR 2.0-3.0) for at least 3-4 weeks post-cardioversion 1
• In RHD patients specifically, the presence of rheumatic mitral stenosis places them at highest risk for stroke, making anticoagulation with warfarin (INR 2.0-3.0) absolutely essential 1

Hemodynamically Stable AF with Fast Ventricular Response (FVR)

Acute AF (<48 hours duration)

For acute AF with FVR in stable RHD patients, prioritize immediate rate control followed by cardioversion within 48 hours to avoid mandatory 3-4 week anticoagulation period. 1

Rate Control Strategy:

• First-line: Intravenous beta-blockers (metoprolol, esmolol) or nondihydropyridine calcium channel blockers (diltiazem, verapamil) to achieve heart rate <100 bpm at rest 1
• Second-line: Add digoxin to beta-blocker or calcium channel blocker if monotherapy insufficient 1
• Third-line: Intravenous amiodarone when other measures unsuccessful or contraindicated 1, 2

Critical pitfall: Digoxin should NOT be used as sole agent for rate control in acute AF, as it is ineffective during high sympathetic states 1, 3

Cardioversion Approach:

• Can proceed directly to cardioversion (electrical or pharmacological) if AF duration <48 hours 1
• Alternative: Perform transesophageal echocardiography to exclude left atrial thrombus, then proceed with immediate cardioversion regardless of duration 1, 4
• Pharmacological cardioversion most effective when initiated within 7 days of AF onset 1

Chronic Persistent AF

For chronic persistent AF in RHD patients, rate control is the primary strategy, with rhythm control reserved for those who remain symptomatic despite adequate rate control. 1

Rate Control Targets:

• Resting heart rate <100 bpm is adequate; strict control (<80 bpm rest, <110 bpm during 6-minute walk) provides no additional benefit 1
• Evaluate rate control during exercise using Holter monitoring or exercise testing, as ventricular rate may accelerate excessively during activity even when controlled at rest 1

Medication Hierarchy:

1. Beta-blockers or nondihydropyridine calcium channel blockers as initial therapy 1, 5
2. Combination of digoxin plus beta-blocker (or calcium channel blocker) for both resting and exercise rate control 1, 6
3. Oral amiodarone when rate cannot be adequately controlled with above combinations 1
4. AV node ablation with permanent pacing when pharmacological therapy insufficient or tachycardia-mediated cardiomyopathy suspected 1

Important consideration: In RHD patients with chronic persistent AF, duration of AF predicts success of rhythm control—those with AF duration >3 years have significantly lower success rates for maintaining sinus rhythm 7

Hemodynamically Stable AF with Controlled Ventricular Response (CVR)

For RHD patients with stable AF and controlled ventricular response, continue current rate control regimen and focus on anticoagulation strategy. 1

• Maintain current medications that achieve resting heart rate <100 bpm 1
• Monitor rate control during activity; adjust medications if symptomatic tachycardia during exercise 1
• Consider rhythm control strategy only if patient remains symptomatic despite adequate rate control 1, 7

Anticoagulation in RHD with AF (Universal Requirement)

All RHD patients with AF require lifelong anticoagulation with warfarin (INR 2.0-3.0) regardless of CHA₂DS₂-VASc score, as rheumatic mitral stenosis is a highest-risk factor for stroke. 1, 8

• Rheumatic mitral stenosis places patients in the highest stroke risk category, mandating anticoagulation even with single episode of AF 1
• INR monitoring required weekly during initiation, then monthly when stable 1, 8
• Direct oral anticoagulants (DOACs) are NOT recommended for rheumatic mitral stenosis—warfarin remains the only validated option 8
• Continue anticoagulation regardless of whether rate control or rhythm control strategy chosen 1

Critical pitfall: Never discontinue anticoagulation in RHD patients even if sinus rhythm restored, as stroke risk remains elevated due to underlying valvular disease 1

Rhythm Control Considerations in RHD

For RHD patients who remain symptomatic despite adequate rate control, a stepwise rhythm control approach can improve functional status and reduce heart failure hospitalizations. 7

Stepwise Approach:

1. Pharmacological cardioversion with antiarrhythmic drugs 7
2. Electrical cardioversion if pharmacological fails 7
3. AF ablation for recurrent symptomatic AF after failed cardioversion 7
4. Pace-and-ablate strategy (AV node ablation with conduction system pacing or biventricular pacing) for refractory cases 7

• RHD patients with AF duration <3 years have better success maintaining sinus rhythm compared to those with longer AF duration 7
• Approximately 35% of RHD patients maintain sinus rhythm after single cardioversion over 11-month follow-up 7
• Those achieving sinus rhythm demonstrate improved functional class, lower NT-proBNP, better 6-minute walk distance, and reduced heart failure hospitalizations 7

Special Considerations for RHD Population

RHD patients with AF have unique considerations that differ from general AF management:

• Younger age at presentation (mean age 56 years) compared to typical AF population 7
• Higher proportion of women (72%) affected 7
• Mandatory warfarin anticoagulation regardless of other risk factors due to rheumatic valvular disease 1, 8
• Higher thromboembolic risk necessitates INR 2.0-3.0 even for rate control strategy 1
• Consider surgical valve repair/replacement as definitive treatment if severe valvular disease present, as this may facilitate rhythm control 7