In restrictive cardiomyopathy the ventricle walls become stiff, so the heart cannot fill properly even though its squeeze is often close to normal. Amyloidosis is the most common cause in the US, and the backup of blood leads to right-sided congestion, arrhythmias and heart failure.
Key symptoms
- Shortness of breath on exertion that slowly gets worse
- Fatigue and poor exercise tolerance
- Leg swelling and a swollen, uncomfortable abdomen
- Palpitations or fainting from arrhythmias
What you find on exam
- Raised jugular venous pressure that may rise further on inspiration (Kussmaul sign)
- Leg edema, enlarged liver and ascites
- Extra heart sounds, often an S3 or S4
- Clues to amyloidosis: carpal tunnel signs, large tongue, bruising around the eyes
Tests
- ECG: low voltage, atrial fibrillation or conduction block
- Echocardiogram: stiff, non-dilated ventricles with large atria and abnormal filling
- BNP and cardiac MRI to look at the heart muscle
- Amyloid workup: serum free light chains, immunofixation and a technetium pyrophosphate scan
Treatment basics
- Loop diuretic such as furosemide, with careful dosing because filling depends on pressure
- Treat the cause, for example tafamidis for transthyretin amyloidosis or chemotherapy for light chain disease
- Anticoagulation if atrial fibrillation develops
- Pacemaker or ICD for conduction disease or dangerous arrhythmias; transplant in advanced cases
Red flags
- Fainting or a very slow or very fast pulse
- Breathlessness at rest or low blood pressure
- Rapid weight gain with worsening swelling despite diuretics
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Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; AAMC Core Entrustable Professional Activities (Core EPAs). Written by Making Synapses. Making Synapses is not affiliated with these organizations.