Cardiomyopathy

Cardiomyopathy refers to a group of diseases (types of cardiomyopathy) that impair the proper functioning of the heart muscle, the myocardium. Whatever the type, the work of cardiomyopathy is to damage the myocardium and reduce its ability to pump blood to the rest of the body.

Cardiomyopathy can be caused by a condition originates from inside or outside of the heart muscle. When the pathogenic factor comes from outside the cardiac muscle, the cardiomyopathy is called extrinsic cardiomyopathy; and intrinsic cardiomyopathy when the deterioration of the myocardium is not due to external cause.

Types of Cardiomyopathy

Dilated cardiomyopathy – this is the most common form of cardiomyopathy, and is often prone to heart transplantation. In this condition, the heart chambers, usually the left ventricle, is weakened and dilated, making blood flow to other organs difficult.

Hypertrophic Cardiomyopathy – this condition causes a thickening of the heart wall, and prevents a normal pumping of blood. In some cases, the disease causes swelling of the wall separating the two lower chambers of the heart, which makes difficult the passage of blood.

Restrictive cardiomyopathy – restrictive cardiomyopathy is a rare form of cardiomyopathy. It obstacles the cardiac muscle to stretch properly, making the wall of the ventricles to lose its flexibility, thereby reducing the amount of blood entering the heart chambers.

Arrhythmogenic right ventricular cardiomyopathy – also called arrhythmogenic right ventricular dysplasia, arrhythmogenic right ventricular cardiomyopathy is a rare form of cardiomyopathy resulted from cardiac electrical disturbances, during replacement of dead cardiac muscle cells in the right ventricle.

Cardiomyopathy Causes

The causes of cardiomyopathy vary depending on the type.

Dilated cardiomyopathy – about 40% of dilated cardiomyopathies are familial. Certain form of dilated cardiomyopathy can be due to viral infection of the heart muscle, or excessive consumption of alcohol, cocaine or antidepressants. Although rare, dilated cardiomyopathy can also be the consequence of pregnancy or rheumatoid arthritis.

Hypertrophic cardiomyopathy – In this condition, the heart muscle becomes thick, making it difficult for blood to flow from the heart to the rest of the body. The cause of hypertrophic cardiomyopathy is not well known. Scientists believe development of the disease may be due to genetic factors, since it is often linked to multiple mutations of genes encoding sarcomeric proteins, a group of protein that give the skeletal and cardiac muscles their striated appearance.

Restrictive cardiomyopathy – this type of heart disease is often idiopathic, the cause is not identified. However, scientists believe that it may be the result of a reduced capacity of the heart chambers, especially the ventricles, to get enough blood. Restrictive cardiomyopathy is sometimes due to deposition of insoluble proteins in a number of tissues (amyloidosis). The disease can also be caused by:

• destruction or inflammation of the tissue of the myocardium
• infiltrative disease, sarcoidosis by example
• metabolic disorder such as Gaucher disease, mucopolysaccharidoses, Fabry disease and carcinoid syndrome.

Arrhythmogenic right ventricular cardiomyopathy – also known as arrhythmogenic right ventricular dysplasia, this form of cardiomyopathy is caused by genetic defects of the desmosomes, structures that join the adjacent cells of the heart muscle together.

Other causative factors of cardiomyopathy include:

• Pregnancy
• Cancer treatment
• Certain viral infections
• Heart valve disorders
• Untreated or chronic high blood pressure
• Prolonged heavy alcohol consumption
• Previous heart attack
• Untreated rapid heart beat
• Nutritional deficiencies in B vitamins, selenium, calcium, magnesium, etc.
• Metabolic diseases, such as diabetes, hypercalcemia, hypocalcemia, thyroid disease, etc.
• Prolonged drug abuse such as cocaine and antidepressants.

Cardiomyopathy Warning Signs and Symptoms

In the early stage of cardiomyopathy, it is often asymptomatic (no signs or symptoms) for most people. As the disease worsens, symptoms begin to submerge. In some cases, congestive heart failure develops. In general, if you have cardiomyopathy, any type, you will experience at least one of these symptoms:

• Unreasonable fatigue
• Shortness of breath with exertion or at rest (dyspnea)
• Accumulation of fluid in your lungs or abdomen
• Reduced physical endurance
• Cardiac arrhythmias
• Swelling of legs and abdomen (dilated cardiomyopathy)
• Swelling of hands and feet (restrictive cardiomyopathy)
• Dizziness, fainting, heart murmurs and chest pain (hypertrophic cardiomyopathy)
• Chest pain or breathing difficulty (see your doctor immediately if you experience these symptoms).

Complications

Cardiomyopathy complications can lead to:

• blood clots
• heart failure
• cardiac arrest
• Sudden death.

Diagnosis

The first step in the diagnosis of cardiomyopathy is a physical examination. Your cardiologist will search for signs of the disease, and ask you appropriate questions which can indicate the pathology. In addition, your doctor may check your medical history looking for disorders that can lead to cardiomyopathy. However, the physical exam is not enough; several tests are necessary to establish an accurate cardiomyopathy diagnosis:

Angiography – this radiographic exam allows your oncologist to take picture of your coronary arteries and vessels that feed the heart. During the procedure, a dye will be injected into your coronary arteries using a catheter inserted into a blood vessel. Angiography helps your doctor to observe blood flow to your heart, and identify potential problems in the coronary arteries. Generally, angiography is performed in a hospital or clinic.

Blood test – The blood test is important in the diagnosis of cardiomyopathy. It allows your physician to identify clotting agents, cholesterol in the blood, and blood glucose (blood sugar). The blood test is also important to measure your brain natriuretic peptide (BNP), a protein produced in the heart, which levels often increased due to complications of cardiomyopathy.

Chest x-ray – this method is performed to produce image of the heart muscle, lungs and bones forming the thoracic cage. It allows your doctor to detect abnormal shape and size of your heart; par example, if it is larger than normal. In addition, it helps your oncologist to confirm presence of a valve disorder and provides important details about your heart condition and its severity.

Echocardiogram – During an echocardiogram, the technician uses ultrasound to produce picture of your heart. The waves recorded allow your health care provider to determine the shape, texture and movement of the valves and the volume and function of your cardiac chambers. In addition, echocardiogram can be performed to determine the risk of clots inside your heart muscle.

Generally, an echocardiogram is recommended if during the physical examination, your oncologist suspects that your heart produces abnormal sounds. The exam can also be done if you experience breathlessness, palpitations or chest pain.

Electrocardiogram (ECG) – This test is done to study the functioning of the heart by measuring its electrical activity. Each heartbeat produces an electrical impulse in your heart that contracts the heart muscle to pump blood to the other organs. By measuring the time the electrical impulse takes to travel through the heart, your cardiologist can determine if electrical activity is normal, fast or irregular.

In addition, electrocardiogram helps to determine if your heart is dilated or overworking. Your cardiologist will recommend an ECG if during the physical exam he suspects signs of arrhythmia, palpitations, dizziness, fatigue or chest pain.

Transesophageal echocardiography (TEE) – TEE is performed to examine the heart to detect blood clots. As an echocardiogram, TEE uses sound waves at high frequency (ultrasound) to make picture of the heart structures. During the procedure, your health care provider you will administer a mild sedative to help you relax. In some cases, you can be supplied with oxygen during the intervention. In general, this test takes 40 minutes or less.

Cardiomyopathy Treatment

In general, cardiomyopathy treatment includes change of lifestyle, medications, surgery or a combination of all.

Lifestyle – to have a significant relief from heart disease, it is important to reduce all risk factors: monitoring and controlling your blood pressure, keep cholesterol levels normal, and monitor your blood glucose if you are diabetic. For this, it is vital to:

• Stop smoking cigarettes
• Limit your intake of alcohol
• Limit your salt intake
• Be physically active
• Have a heart healthy weight
• Adopt a heart healthy
• live a stress-free life
• Eat a diet rich in fruits and green vegetables and low in saturated fats.
  

Medications

If the cardiomyopathy is asymptomatic, you will not be prescribed medication but rather a regular medical follow up along with a healthy lifestyle. If the cardiomyopathy present symptoms (symptomatic cardiomyopathy), a drug therapy is necessary. There are many drugs that can dramatically improve your life if you suffer from a symptomatic cardiomyopathy. Three major classes of drugs may be used to treat cardiomyopathy:

Beta Blockers – Beta-blockers are used to treat high blood pressure, heart failure, irregular heartbeat, shortness of breath and chest pain. This class of drugs works by slowing the heart rate and decrease the intensity of the beat. Carvedilol (Coreg) and metoprolol (Lopressor, Toprol XL) are some of the beta blockers that your doctor can recommend you to take.

Drugs used to treat high blood pressure, diabetes, asthma, bronchitis and emphysema, as well as certain antidepressants and allergy can interact with beta blockers. Talk to your doctor before taking these drugs. Beta-blockers can cause fatigue and erectile dysfunction in men. Other adverse effects may include:

• Coldness of hands and feet
• Dizziness
• Dryness of the mouth, eyes and skin.

ACE inhibitors – This class of drugs are used in cardiomyopathy treatment in cases of hypertension, heart failure, heart attack, heart failure, and any condition that makes you susceptible to coronary artery disease. They work by controlling blood pressure and facilitating the pumping of the heart. In addition, ACE inhibitors can reduce fatigue and breathlessness caused by cardiomyopathy.

Some of the ACEs include:

• enalapril (Vasotec)
• lisinopril (Zestril, Prinivil)
• ramipril (Altace)
• captopril (Capoten).

Several studies have shown that ACE inhibitors reduce the risk of heart attack, stroke and death in people with a history of coronary disease. In addition, when taken with a healthy diet, they reduce the risk of heart attack and death in people with heart failure.

The following drugs can interact with ACE inhibitors, talk to your cardiologist before taking them:

• anti-inflammatory drugs (NSAIDs) – they tend to reduce the curative effects of ACE inhibitors
• Antacids containing aluminum or magnesium – they can also reduce the therapeutic effects of ACE inhibitors
• potassium supplements – they can increase your potassium levels when combined with ACE inhibitors
• drugs used to treat cough, flu, hay fever or sinus problems – they can increase your blood pressure when associated with ACE inhibitors.

ACE inhibitors can cause:

• Dizziness
• Weakness
• Diarrhea
• Nausea
• Persistent dry cough
• Headache.
  

Angiotensin II receptor antagonists – also called angiotensin receptor blockers (ARBs), this class of drugs is used to treat hypertension and heart failure. ARBs block angiotensin II action, an enzyme that can narrow blood vessels. They work by relaxing blood vessels, thus, reducing blood pressure. The two most common of ARBs include losartan (Cozaar) and valsartan (Diovan).

However, angiotensin receptor blockers should not be taken during pregnancy and/or breast-feeding. These drugs increase the risk of limb or craniofacial malformations and bone deformities of the skull of the fetus.

Talk to your doctor before taking anti-inflammatory drugs like ibuprofen, naproxen and indomethacin. Taking them along with angiotensin II receptor antagonists can increase blood pressure and lead to major complications.

Antagonists of angiotensin can cause:

• Cough
• Dizziness
• Headache
• Drowsiness
• Diarrhea
• Increased potassium levels
• Low blood pressure.

Other medications

Depending on symptoms, your doctor may prescribe you other medications such as:

Diuretics – your cardiologist may recommend you to take diuretics if you hold too much water in your body, or if you experience shortness of breath; diuretics promote elimination of water and reduce high blood pressure and breathlessness.

Anticoagulants – These medications prevent blood clotting, and facilitate normal blood flow. You may be prescribed anticoagulants if you suffer from episodes of atrial fibrillation.

Surgical treatment

If you have an advanced cardiomyopathy that presents complications, your doctor may recommend one of these surgeries:

Septal myotomy-myectomy – this surgery is applied in cases of severe obstructive or when other methods do not produce satisfying results. During the procedure, your surgeon dig a trench in the wall of the hypertrophied septum to reduce the muscle mass. In some situations, the surgeon may replace the mitral valve with an artificial valve. Septal myotomy-myectomy is often effective; it reduces the risk of sudden death and improves symptoms.

Alcohol septal ablation – this surgical procedure is recent in the treatment of hypertrophic cardiomyopathy; it is introduced by Sigwart in 1994 as an alternative to surgery. During the procedure, your surgeon injects a small amount of absolute alcohol in a branch of a coronary artery to cause a small heart attack localized in the septum in order to destroy a part of it. The intervention aims at reducing the mass of the septum to facilitate better blood circulation. The alcohol septal ablation often gives good results. Most of the times, the rate of reduction of the obstruction and improvement of symptoms is identical to that of surgery. This is a short procedure that takes approximately 30 minutes to complete.

Pacemaker – if you have slow heartbeat, your surgeon may implant a pacemaker (battery). This device, once implanted in your body, delivers electrical pulses to the heart, which accelerates its functions when it is too slow. In general, the pacemaker implantation is performed under local anesthetic. You should always take precautions when you wear a pacemaker. Talk to your cardiologist for more information.

Implantable cardioverter defibrillator (ICD) – An ICD is a type of pacemaker placed in your chest or abdomen. It is used as a preventive measure to control irregular heartbeats, and thus prevent sudden death, mainly in patients having heart disease with mechanical malfunction of the left ventricle. However, this therapy is not popular because of its cost.

Heart transplantation – a heart transplant is performed to replace a diseased heart with a healthy heart, taken from a donor. It is reserved for severe cases – patients with severe and irreversible heart failure – for which life expectancy is low. Because there is still a shortage of organ donation, a heart transplant is always limited.

If your only chance to live based on a heart transplant, you will be placed on a “transplant waiting list“. You can be called at any time of day or night, and you should go in the shortest time possible to the transplant center.

Cardiomyopathy Prevention

Living a healthy lifestyle and consuming a healthy diet can help you decrease all cardiovascular disease including cardiomyopathy; however, the disease is not easily preventable. If you have family history of cardiomyopathy, the wise option is to see your doctor for regularly regular medical check up to discover the disease in its early stage.

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