Amyloid cardiomyopathy

Amyloid cardiomyopathy is a form of restrictive cardiomyopathy and can result in significant progressive diastolic congestive heart failure.

The familial form of amyloid cardiomyopathy is caused by a gene mutation resulting in a form of amyloid deposition called transthyretin. This can progress rapidly and can result in end-stage diastolic heart failure. Senile amyloid cardiomyopathy occurs much more slowly and is from the “wild type” or naturally occurring transthyretin amyloid protein. Diagnosis is made by myocardial biopsy. The ECG will show low voltage despite significant left and right ventricular hypertrophy on echocardiography. Pericardial effusions are frequently present and the left and right atrium can be massively enlarged on echocardiography. Restrictive filling patterns (grade III or IV diastolic dysfunction) are commonly seen once heart failure symptoms occur.

The only major therapy for familial amyloid cardiomyopathy is combined heart-liver transplantation (the liver is included since it is the location of the transthyretin production). Medical management is unsuccessful and is directed at improving symptoms.

Below is an ECG from a patient with amyoloid cardiomyopathy. Note the low voltage despite left and right ventricular hypertrophy on echocardiography.

LowVoltage