What is the best course of action for a patient with rheumatic heart disease (RHD), presenting with atrial fibrillation (AF) in rapid ventricular response (RVR) and tachycardia, without a available blood pressure (BP) reading?

Emergency Management of AF with RVR in Rheumatic Heart Disease

This patient requires immediate electrical cardioversion given the absence of blood pressure measurement at HR 200 bpm, as this likely represents hemodynamic instability that mandates urgent direct-current cardioversion rather than pharmacological rate control. 1

Immediate Hemodynamic Assessment

• Obtain blood pressure immediately to determine if the patient is hemodynamically stable or unstable 1
• If the patient shows severe hemodynamic compromise (hypotension, altered mental status, chest pain, pulmonary edema), proceed directly to synchronized cardioversion without delay 1
• The absence of a BP reading in a patient with HR 200 bpm should be treated as presumed hemodynamic instability until proven otherwise 1

If Hemodynamically Stable: Pharmacological Rate Control

First-Line Therapy

Intravenous digoxin or amiodarone is recommended as first-line therapy for acute rate control in patients with rheumatic heart disease and AF with RVR, rather than beta-blockers or calcium channel blockers 2. This differs from typical AF management because:

• Rheumatic heart disease patients often have underlying valvular dysfunction (typically mitral stenosis) that may be associated with heart failure 1
• IV beta-blockers and calcium channel blockers should be used with extreme caution in patients with overt congestion or heart failure with reduced ejection fraction 2
• Digoxin is particularly effective for controlling resting heart rate in patients with heart failure and left ventricular dysfunction 2

Dosing Strategy

• IV digoxin: Load with 0.25 mg IV, may repeat 0.25 mg every 2-4 hours up to 1.5 mg total over 24 hours 2
• IV amiodarone: 150 mg IV bolus over 10 minutes, followed by 1 mg/min infusion for 6 hours, then 0.5 mg/min 2
• Target heart rate: <110 bpm at rest initially 1

Alternative if No Heart Failure Present

If the patient has preserved ejection fraction and no signs of decompensation:

• IV diltiazem 0.25 mg/kg (typically 20 mg) IV push over 2 minutes, may repeat 0.35 mg/kg in 15 minutes if needed 2
• IV metoprolol 2.5-5 mg IV push over 2 minutes, may repeat every 5 minutes up to 15 mg total 2

Critical caveat: Diltiazem achieves rate control faster than metoprolol but should be avoided if any concern for decompensated heart failure exists 3, 4

Combination Therapy if Monotherapy Fails

• Add digoxin to beta-blocker or calcium channel blocker if single-agent therapy is insufficient 2
• This combination is reasonable to control both resting and exercise heart rate 2
• Dose must be modulated to avoid bradycardia 2

Critical Pitfalls to Avoid

Pre-excitation (WPW Syndrome)

Never use AV nodal blocking agents (beta-blockers, calcium channel blockers, digoxin) if pre-excitation is present on ECG, as they can paradoxically accelerate conduction through the accessory pathway and precipitate ventricular fibrillation 2

• If WPW suspected: Use IV procainamide or IV ibutilide instead 2
• Electrical cardioversion remains the safest option if hemodynamically unstable 1

Decompensated Heart Failure

IV calcium channel blockers are contraindicated in decompensated heart failure as they may exacerbate hemodynamic compromise 2

• Use IV digoxin or amiodarone instead 2
• IV beta-blockers should also be avoided in overt decompensation 2

Anticoagulation Management

Patients with rheumatic heart disease and AF require warfarin anticoagulation, not direct oral anticoagulants (DOACs), regardless of CHA₂DS₂-VASc score 1

• Rheumatic mitral stenosis is classified as valvular AF, which is a contraindication to DOACs 2, 1
• Target INR: 2.0-3.0 2
• Anticoagulation should be initiated immediately unless contraindicated 2

Transition to Oral Therapy

Once acute rate control achieved:

• Oral digoxin 0.125-0.25 mg daily for maintenance 2
• Consider adding oral metoprolol 25-50 mg twice daily if preserved ejection fraction 1
• Oral diltiazem 120-180 mg daily (extended release) if no heart failure 1

Assessment for Tachycardia-Induced Cardiomyopathy

• At HR 200 bpm, tachycardia-induced cardiomyopathy is highly likely and should be assumed until proven otherwise 1
• Obtain echocardiogram within 24 hours to assess ventricular function 1
• If confirmed, AV node ablation with permanent pacemaker may be necessary if pharmacological therapy fails 2, 1

Rhythm Control Consideration

• Younger patients with recent-onset AF may benefit from rhythm control strategy rather than rate control alone 1, 5
• However, in rheumatic heart disease with chronic AF, rate control is typically the preferred long-term strategy 1
• If pursuing cardioversion, ensure adequate anticoagulation for ≥3 weeks or perform TEE to exclude left atrial thrombus 5

Monitoring Parameters

• Continuous cardiac monitoring until heart rate <110 bpm sustained 1
• Reassess blood pressure every 15 minutes during acute management 1
• Monitor for signs of worsening heart failure (increased oxygen requirement, pulmonary edema) 4
• Close outpatient follow-up within 1-2 weeks to assess response and adjust therapy 1, 5