Diagnosing Cardiac Amyloidosis: 5 Things to Know

Cardiac amyloidosis is a progressive, infiltrative cardiomyopathy in which there are abnormal amyloid fibril deposits in the interstitial space between cardiac myocytes. Over time, this infiltration leads to progressive diastolic dysfunction with a restrictive pattern and prominent right ventricular failure. Managing cardiac amyloidosis is challenging and complex because patients often experience refractory symptoms, medication intolerance, multisystem involvement, and hypotension. Although amyloidosis was thought to be rare, improved diagnostic studies, better recognition of symptoms, and the availability of newer therapies have led to increased diagnosis and incidence.

As new targeted treatments become available, including those that improve neurologic symptoms, early identification of amyloidosis is important to delay disease progression and improve quality of life. Several national and international societies, including the American College of Cardiology and American Heart Association, have issued scientific statements to guide diagnosis and management of this disease.

Here are five things to know about the diagnostic workup of cardiac amyloidosis.

1. Disease diagnosis requires a high index of suspicion in the presence of specific clinical manifestations.

Although cardiac amyloidosis cannot be diagnosed through routine testing, there are several clinical features or "red flags" that should raise suspicion for amyloidosis and which warrant further testing. Clinical manifestations of cardiac amyloidosis include cardiac (eg, heart failure, atrial fibrillation, bradyarrhythmias, conduction abnormalities, pacemakers), musculoskeletal (carpal tunnel syndrome, back pain or lumbar stenosis, ruptured distal biceps tendon), polyneuropathic (neuropathy in the hands and feet, muscle weakness, difficulty ambulating, falls), and autonomic dysfunction (orthostatic hypotension, intolerance to blood pressure medications, chronic diarrhea, chronic constipation, unintended weight loss, erectile dysfunction) symptoms.