Cardiac Amyloidosis
Amyloidosis is a life-threatening heart condition. “Amyloid” is an abnormal protein that is typically produced in either your bone marrow or liver but can be deposited in any tissue or organ. When it deposits in the walls of your heart, it makes the heart muscle stiff and unable to relax. This affects both the ability of the heart to fill and the electrical rhythm of the heart. As a result the heart pumps less blood causing fluid to accumulate in the lungs which eventually causes shortness of breath and generalized swelling.
Types of Cardiac Amyloidosis
- AL (Immunoglobulin Light Chain) Amyloidosis: This is the most common type of cardiac amyloidosis. It can affect your heart, kidneys, skin, nerves and liver. AL amyloidosis occurs when your bone marrow produces abnormal antibodies that can't be broken down. The antibodies are deposited in your tissues as amyloid; therefore, interfering with normal function.
- AA (Apo Serum Amyloid A) Amyloidosis: This type of cardiac amyloidosis can affect your kidneys but occasionally your digestive tract, liver or heart. It occurs along with chronic infectious or inflammatory diseases, such as rheumatoid arthritis or inflammatory bowel disease.
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ATTR (Transthyretin) Amyloidosis: Transthyretin is a protein made by the liver to help carry thyroid hormone
and vitamin A in your blood. Transthyretin amyloidosis has 2 forms, hereditary
and senile:
- Hereditary or Familial Amyloidosis: This is caused by a DNA error most commonly seen in the African, Caribbean, and Portuguese communities. Over time, the transthyretin protein builds up in the organs and causes organ failure. This form of transthyretin amyloidosis can affect the heart, nerves, and kidneys.
- Senile Amyloidosis: This is not caused by a DNA error. In this case, it is not known why the transthyretin protein becomes abnormal and begins to accumulate. This form of transthyretin amyloidosis usually affects the hearts of Caucasian men around 80 years of age.
Causes of Cardiac Amyloidosis
Amyloidosis is caused by changes in proteins that make them insoluble, leading them to deposition in organs and tissues. Changes in proteins that make them amyloid proteins occur because of gene mutations.
Symptoms of Cardiac Amyloidosis
The symptoms of cardiac amyloidosis can mimic those of heart disease. Some symptoms include:
- Chest pain
- Chronic Cough: A condition in which a cough lasts longer than 8 weeks in adults, or 4 weeks in children.
- Confused or impaired thinking
- Disturbed sleep
- Anemia: Low red blood cell count.
- Fatigue
- Heart arrhythmias
- Involuntary weight loss
- Nausea and/or vomiting
- Numbness, tingling or pain in your hands or feet including carpal tunnel syndrome and spinal stenosis.
- Shortness of breath
- Painful and tender joints that are most often present in the knees, ankles, elbows and wrists.
- Swelling of the legs, ankles, and abdomen.
- Torn tendons
Diagnosis of Cardiac Amyloidosis
Diagnosis as early as possible can help prevent further organ damage. Precise diagnosis is important because treatment varies greatly, depending on your specific condition. Your doctor is likely to start with a thorough medical history and physical exam. After that, you may have one or more of the following tests and procedures:
- Blood tests
- Computed tomography (CT scan)
- Magnetic resonance imaging (MRI)
- Echocardiogram (ECHO)
- Electrocardiogram (EKG/ECG)
- Urinalysis
- Biopsy
Treatment of Cardiac Amyloidosis
There's no cure for amyloidosis. But treatment to manage signs and symptoms and limit further production of amyloid protein is available. Treatment options include lifestyle changes, medications, and medical or surgical procedures.
Lifestyle Changes
- Avoid activities that worsen symptoms.
- Watch for signs of fluid retention.
- Eat a heart-healthy diet.
- Make and keep appointments to see your doctor for routine check-ups and follow-up tests.
Medications
- Thrombolytic therapy is the administration of drugs called “lytics” or “clot busters” that will help break up or dissolve blood clots.
- Chemotherapy will help stop or slow the growth of cancer cells.
- Diuretics “water pills” will help reduce the amount of fluid retention in your body.
- Heart rate medications will help regulate your heartbeat.
- Immunomodulatory drugs will help readjust your immune system’s function.
- Transthyretin stabilizers and transthyretin gene silencers.