CARDIAC AMYLOIDOSIS

Cardiac amyloidosis (CA), also known as "stiff heart syndrome," is an exceedingly rare condition characterized by abnormal protein deposits in the heart muscle called amyloids. Over time, these clumps multiply and can disrupt the heart's rhythm or make it work too hard, essentially "stiffening" it.  But cardiac amyloidosis is not to be ignored -- if untreated, it is always fatal.

Cardiac amyloidosis is more common in men than in women. The disease is rare in people under age 40. 

Amyloidosis can also occur in other organs; even with CA, it may also be in the liver or another vital area such as the bone marrow. It is considered "semi-malignant" because of the way its abnormalities multiply.

Causes

Cardiac amyloidosis usually occurs during primary amyloidosis (AL type amyloidosis).Primary amyloidosis is often seen in people with multiple myeloma cancer.

It is the most typical type of restrictive cardiomyopathy. Cardiac amyloidosis may affect the way electrical signals move through the heart (conduction system). This can lead to arrhythmias and conduction disturbances (heart block).

Secondary amyloidosis (AA type) rarely affects the heart. However, a form of secondary amyloidosis called senile amyloidosis involves the heart and blood vessels. Senile amyloidosis is caused by overproduction of a different protein. 

Signs and Symptoms

Signs may include:

• Abnormal sounds in the lung (lung crackles) or a heart murmur
• Blood pressure that is low or drops when you stand up
• Enlarged neck veins
• Swollen liver

Symptoms may include.

• Palpitations (sensation of feeling heart beat)
• Swelling of legs, ankles, or other part of the body (See: abdominal swelling)
• Excessive urination at night
• Fatigue, reduced activity tolerance
• Shortness of breath with activity
• Trouble breathing while lying down

Some patients may have no symptoms.

Diagnosis

It can be difficult to diagnose cardiac amyloidosis, because the signs can be related to a number of different conditions.

The following tests may be performed to help diagnose cardiac amyloidosis:

• Chest or abdomen CT scan (this is considered the "gold standard")
• Coronary angiography
• Echocardiogram
• Magnetic resonance imaging (MRI)
• Nuclear heart scans (MUGA, RNV)

An ECG may show problems with the heart beat or heart signals (conduction disturbance).

A cardiac biopsy is used to confirm the diagnosis. A biopsy of another area, such as the abdomen, kidney, or bone marrow, is often done to confirm the diagnosis.

Treatment.

• The therapeutic approach consists of specific treatment of amyloidosis and supportive treatment for cardiac-related symptoms. The treatment depends on the type of amyloidosis and the stage of disease.
• The mainstay of supportive treatment of cardiac failure is diuretic therapy.Many patients are required to weigh themselves daily to make sure their bodies aren't retaining too much fluid.
• You can continue to exercise as long as feel like you can.
• Your doctor may tell you to change your diet. This may include salt and fluid restrictions.
• Patients with atrial fibrillation might take digoxin, calcium channel blockers and beta blockers. Since cardiac amyloidosis patients are often sensitive to any type of side effects, physicians must carefully monitor the dosage of any of these drugs.
• Many patients undergo chemotherapy. Some are fitted with an implantable cardioverter-defribrillator (AICD). Those who experience any problems with heart signals typically receive a pacemaker. Doctors also often prescribe the steroid Prednisone.
• When a cardiac amyloidosis patient ends up with very poor heart function, a heart transplant is sometimes the only option.
• A promising new treatment available at some of the major hospitals  is an autologous stem cell transplant. Doctors collect cells from the patient's bone marrow prior to administering high-dose chemotherapy.They then transplant the stem cells back into the patient's body with the expectation that they will create healthy bone marrow and stop the formation of new amyloid deposits. Following the transplant, the medical staff carefully monitors the patient for complications such as infection. Many individuals remain confined to their homes for months to avoid exposure to germs that could prove disastrous because of their compromised immune systems.If it works, the transplant does not cure cardiac amyloidosis. It merely induces a remission and extends the patient's life.

Complications

• Atrial fibrillation or ventricular arrhythmias
• Congestive heart failure
• Fluid buildup in the abdomen (ascites)
• Increased sensitivity to digoxin
• Low blood pressure and dizziness from excessive urination (due to medication)
• Sick sinus syndrome
• Symptomatic cardiac conduction system disease (arrhythmias related to abnormal conduction of impulses through the heart muscle)

Please Note-

Amyloidosis is a serious disease and its diagnosis and management is complex, requiring expertise on the part of the physicians involved, a collaborative approach among specialists, and an effort by the patient to carefully follow dietary and treatment-related advice. Patients with cardiac involvement are perhaps the most complex for a physician to treat, as the disease has somewhat unique features compared to many other forms of cardiac disease.

Call your doctor if  new symptoms develop, particularly:

• Dizziness when you change position
• Excessive weight (fluid) gain
• Excessive weight loss
• Fainting spells
• Severe breathing difficulty