Chronic Rheumatic Heart Disease and Secondary Prophylaxis
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Direct answer
Chronic rheumatic heart disease is persistent valve damage, most often mitral stenosis, left behind after acute rheumatic carditis. Secondary prophylaxis with benzathine penicillin prevents recurrent rheumatic fever, and its duration depends on carditis and residual valve disease. Mitral stenosis with atrial fibrillation needs vitamin K antagonist anticoagulation, because direct oral anticoagulants are avoided in moderate to severe rheumatic mitral stenosis.
What you must remember
- Commonest valve: the mitral valve is most often involved, with mitral stenosis the commonest lesion and mitral regurgitation frequently coexisting.
- Mitral stenosis signs: a loud first heart sound, an opening snap and a mid-diastolic rumble with presystolic accentuation (only in sinus rhythm), with a shorter S2 to opening snap interval meaning more severe stenosis.
- Mitral facies and imaging: a malar flush with a long-standing stenosis, and left atrial enlargement on chest X-ray with a double density behind the right heart border.
- Atrial fibrillation: left atrial enlargement predisposes to atrial fibrillation, left atrial thrombus and systemic embolism.
- Benzathine penicillin: 1.2 million units intramuscularly for patients weighing 27 kg or more, with 0.6 million units for lighter children, every 3 to 4 weeks.
- Duration: 5 years or until age 21 after fever without carditis, 10 years or until age 21 after carditis without residual disease, and 10 years or until age 40 with residual valve disease, whichever is longer.
- Anticoagulation: warfarin with a target INR of 2 to 3 for atrial fibrillation with rheumatic mitral stenosis.
- Valve intervention: percutaneous mitral balloon valvotomy suits pliable valves without left atrial thrombus, while calcified or heavily fibrosed valves need surgery.
A schedule for benzathine penicillin in a young patient
A 14-year-old girl with a diagnosed mitral stenosis and a history of carditis is due for her next penicillin injection. The steps below set out the dose, interval and duration that apply to her.
- Confirm the lesion by echo: Echocardiography establishes the valve lesion and its severity, because the clinical murmur alone can mislead and subclinical disease is common.
- Set the dose by weight: Give benzathine penicillin G 1.2 million units intramuscularly if she weighs 27 kg or more, and 0.6 million units for a lighter child. The interval is every 3 to 4 weeks, with the shorter gap favoured in high-prevalence settings.
- Fix the duration by carditis and valve status: She has carditis with residual valve disease, so the course runs for 10 years or until age 40, whichever is longer. A child with fever alone needs a shorter course.
- Plan for missed doses and allergy: A missed injection should be given as soon as it is remembered, and the 3 to 4 week cycle resumed from that date. A penicillin-allergic patient needs an oral alternative chosen with specialist advice.
- Plan valve surveillance: Repeat echo at intervals set by the severity of the lesion, watching for new atrial fibrillation, left atrial thrombus and heart failure. Ask about dyspnoea, haemoptysis and palpitations at each visit to time referral for valvotomy or surgery.
Where the examiner tests valve and prophylaxis knowledge
Rheumatic heart disease questions usually ask which valve, which sign or which drug.
- Trap: choosing aortic stenosis as the typical rheumatic lesion Correct: the mitral valve is most often affected, and mitral stenosis is the commonest rheumatic lesion.
- Trap: prescribing a direct oral anticoagulant for atrial fibrillation with rheumatic mitral stenosis Correct: vitamin K antagonists remain the standard in moderate to severe rheumatic mitral stenosis.
- Trap: stopping prophylaxis at age 21 in a patient with residual valve disease Correct: residual valve disease extends the course, commonly to age 40, so the longer rule applies.
- Trap: selecting balloon valvotomy for every stenotic valve Correct: percutaneous valvotomy suits pliable valves without left atrial thrombus, whereas calcified or heavily fibrosed valves need surgery.
Frequently asked questions
What is the commonest valve lesion in chronic rheumatic heart disease?
Mitral stenosis is the commonest valve lesion in chronic rheumatic heart disease, because the mitral valve is most often involved after rheumatic carditis. Mitral regurgitation frequently coexists, while aortic and tricuspid involvement is less common.
Which heart sounds are characteristic of mitral stenosis?
Mitral stenosis produces a loud first heart sound, an opening snap and a mid-diastolic rumble with presystolic accentuation. The shorter the interval between the second heart sound and the opening snap, the more severe the mitral stenosis.
How long should benzathine penicillin prophylaxis last in rheumatic heart disease?
Benzathine penicillin prophylaxis in rheumatic heart disease usually lasts 10 years from the last episode or until age 40, whichever is longer, when residual valve disease is present. Shorter courses apply to rheumatic fever without carditis, and the category depends on the carditis history and valve status.
Why are direct oral anticoagulants avoided in rheumatic mitral stenosis?
Direct oral anticoagulants are avoided in moderate to severe rheumatic mitral stenosis because vitamin K antagonists remain the standard anticoagulant in this setting. Warfarin with a target INR of 2 to 3 is the usual choice for atrial fibrillation with rheumatic mitral stenosis.