Cardiac amyloidosis is a clinical disorder caused by the deposition of insoluble by-products from proteins called amyloid, which are approximately 10 nanometers wide.
Amyloid deposits form on the outside of cells in the heart muscle, affecting its ability to pump blood.
These abnormalities result in amyloid fibrils and can manifest as primary, secondary, familial, or senile amyloidosis.
Amyloidosis can affect multiple organs (e.g., heart, liver, kidney, skin, eyes, lungs, nervous system), resulting in various clinical manifestations.
Cardiac involvement is a progressive disorder resulting in early death due to congestive heart failure and arrhythmias. Cardiac involvement can occur as part of a systemic disease or a localized phenomenon.
Cardiac amyloidosis symptoms
Symptoms of cardiac amyloidosis mimic those of heart failure, including:
- Thickened and less flexible heart tissue
- Shortness of breath
- Fatigue
- Leg swelling
- Heart palpitations
- Dizziness
Diagnosis of cardiac amyloidosis
To confirm a diagnosis of cardiac amyloidosis, you will need a heart biopsy or a technetium pyrophosphate scan.
A heart biopsy is a minor surgical procedure in which a small sample of heart tissue is removed and examined under a microscope by a doctor.
A technetium pyrophosphate scan is similar to an MRI and gives an image of the heart. A dye is injected before the scan and will cause the ‘brightening’ of transthyretin amyloidosis (ATTR). If any tests indicate transthyretin amyloidosis (ATTR), genetic testing is recommended to confirm the subtype.
- Light chain (AL) amyloidosis and transthyretin (ATTR) are most likely to damage the heart.
- Treatment depends on the specific subtype of amyloidosis. These can include drugs, chemotherapy, and stem cell transplantation.
Other tests that might be recommended:
- Electrocardiogram (ECG)
- echocardiogram
- Blood analyses
- Urine analysis
Cardiac amyloidosis treatment
Cardiac amyloidosis is a severe disease that requires a multidisciplinary approach. Although the disease cannot be cured, treatment can slow the progression of amyloid deposits and treat damage to the heart.
Treatment depends on the subtype and may involve a combination of these approaches:
- Drug to stabilize transthyretin protein.
- A medical approach to inhibit the transthyretin gene and prevent the body from producing the transthyretin protein.
- Medicines to reduce swelling or control irregular heartbeats
- A pacemaker to regulate the heartbeat
- Chemotherapy.
- Automatic stem cell transplant.
- Participation in clinical trials to test new therapies.