Cardiomyopathy

Cardiomyopathy is a disease of the heart muscle. It is a very serious disease in which the heart muscle becomes inflamed and doesn't work as well as it should.

Cardiomyopathy can be classified as primary or secondary. Primary cardiomyopathy can't be attributed to a specific cause, while secondary cardiomyopathy can be related so some other disease such as high blood pressure, heart valve disease, artery diseases or congenital heart defects. It's often associated with diseases involving other organs as well as the heart.

Incidence of the condition

The incidence of cardiomyopathy in US is 400,000 cases per year. This disease afflicts 2-3 million people in the United States. Several studies have found that 5 years after the initial presentation of the disease, 42% of women and 62% of men had died. Long-term survival was found to be inversely proportional to the severity of the disease on the initial diagnosis.

 

 

Signs and symptoms

Although some people who develop cardiomyopathy may have no signs and symptoms in the early stages of the disease, as the condition advances, signs and symptoms usually appear.

Some of the most common signs are:

•    Breathlessness with exertion or even at rest
•    Swelling of the lower extremities
•    Distention of the abdomen with fluid
•    Fatigue
•    Irregular heart rhythm
•    Dizziness, lightheadedness and fainting
•    Swelling of the legs, ankles, or other portion of the body
•    Abdominal swelling or enlargement
•    Low amount of urine during daytime
•    A need to urinate at night
•    Changes in mental status
•    Decreased alertness

No matter what type of cardiomyopathy we are talking about, it is important to stress out that signs and symptoms tend to progress over time unless the condition is treated. 

Possible causes and types of cardiomyopathy

The causes of the common forms of cardiomyopathy include:

•    Dilated cardiomyopathy
This is definitely the most common form of cardiomyopathy, in which the left ventricle, the heart's main pumping chamber, becomes enlarged and its pumping ability becomes less strong.
Although this type of cardiomyopathy can affect people of all ages, it occurs most often in middle-aged people and with a greater incidence among men than women.  
•    Hypertrophic cardiomyopathy
This type involves the abnormal growth of heart muscle, mostly affecting the muscle of the left ventricle. Because of the thickening, the heart tends to stiffen and the size of the pumping chamber may shrink, interfering with the heart's ability to deliver blood to the body. This disorder can develop at any age, but it tends to be more severe among those people who were diagnosed with it during childhood.
•    Restrictive cardiomyopathy
During this condition, the heart muscle becomes very rigid and less elastic, interfering with its’ ability to expand and fill the ventricles with blood between heartbeats or contractions. It can occur for an unknown reason or may result from diseases elsewhere in the body that affect the heart.  
•    Alcoholic cardiomyopathy
This is a type of dilated cardiomyopathy that usually begins about 10 years after the start of heavy alcohol consumption. It can occur with both typical signs of heart failure, as well as with atrial fibrillation or other heart rhythm problems.
•    Peripartum cardiomyopathy
This is a dilated cardiomyopathy appearing in women during the last trimester of pregnancy, or after childbirth.
•    Ischemic cardiomyopathy
It is caused by heart attacks, which leave scars in the heart muscle. The affected myocardium is then unable to contribute to the pumping. The larger the scars, the higher the chance of developing ischemic cardiomyopathy.

Although there are many conditions that can cause cardiomyopathy, in most people the cause is unknown. In some people, however, doctors are able to identify the cause or contributing factors, including some that affect the heart and cardiovascular system. Some of the most common causes are also:

•    Sustained high blood pressure
•    Heart valve problems
•    Heart tissue damage from a previous heart attack
•    Chronic rapid heart rate
•    Metabolic disorders, such as thyroid disease or diabetes
•    Nutritional deficiencies of essential vitamins and minerals, such as thiamin (vitamin B-1), selenium, calcium and magnesium
•    Pregnancy
•    Excessive use of alcohol over many years
•    Abuse of cocaine or antidepressant medications, such as tricyclic antidepressants
•    Use of some chemotherapy drugs to treat cancer
•    Certain viral infections, which may injure the heart and trigger cardiomyopathy

Screening and diagnosis of cardiomyopathy

Before any other tests, every doctor should conduct a physical examination and inquire about patient’s medical history, including the family history of heart problems. If a doctor suspects cardiomyopathy as a possible cause, patient may need to have several tests to confirm the diagnosis and rule out other conditions and some of the most common tests are:

•    Chest X-ray
It is clear that an X-ray image of the heart will show whether it's enlarged or not.
•    Echocardiogram
This is a very good diagnostic tool because it uses the sound waves or ultrasound to non-invasively create images of patient’s heart. Doctor can then view the size of the heart and its motions.
•    Electrocardiogram (ECG)
This is also a noninvasive and very effective test. It can be simply done with small electrode patches that are being attached to the patient’s skin to measure the electrical impulses from the heart. It can show disturbances in the electrical activity of the heart, which may identify abnormal heart rhythms.
•    Cardiac catheterization and biopsy
During this procedure, a thin tube called catheter is guided through patient’s blood vessels and into heart, where a small sample can be extracted for analysis in the laboratory. It can also measure pressure within the chambers of patient’s heart.
•    Blood tests
o    A specific blood test can measure the quantity of the brain natriuretic peptide (BNP), a protein produced in heart. It is proven that blood level of brain natriuretic peptide rises when heart is subjected to the stress of congestive heart failure.
o    Another blood test measures iron level. Having too much iron in blood may indicate an iron overload disorder called hemochromatosis. Accumulating too much iron in your heart muscle can weaken it.
o    Thyroid problems that can affect the heart can also be detected by a simple blood test.
o    Blood Chemistries: CBC, lipid profile (cholesterol test), and cardiac enzymes.
o    CBC (Complete Blood Count). Red and white blood cells are counted, as well as platelets.
o    Urine pregnancy test
o    Urine toxicology screen

Possible complications if left untreated

Several studies done in the past have proven that untreated cardiomyopathy can lead to several complications of which some are very dangerous. The most common are:
•    Blood clots
All types of cardiomyopathy can make a patient more susceptible to forming blood clots in their heart. Problem is that, if these clots are pumped out of the heart and enter th circulatory system, they can obstruct the blood vessels and blood flow to vital organs, including your heart and brain. This is a lethal condition. If clots develop on the right side of your heart, they may travel to your lungs. This is why cardiomyopathy patients are given anticoagulant medications.
•    Heart murmur
Since the heart is extremely enlarged due to this condition, two of the heart's four valves may not close properly because they stay small! This is often leading to the backflow of blood and heart murmurs.
•    Cardiac arrest
It is proven that all forms of cardiomyopathy can lead to abnormal heart rhythms. 

Treatment of cardiomyopathy

Goals of the treatment include symptom relief, improved cardiac output, shortened hospital stays, fewer ED visits, reversal of injury process, and decreased mortality.

The most common treatments include:

•    Dilated cardiomyopathy

Medications

Doctors often prescribe medications for dilated cardiomyopathy. The most commonly used are:
o    Angiotensin-converting enzyme (ACE) inhibitors such as enalapril (Vasotec), lisinopril (Zestril, Prinivil), ramipril (Altace) or captopril (Capoten)
o    Diuretics, such as furosemide (Lasix), can reduce fluid retention.
o    Beta blockers — such as atenolol (Tenormin), carvedilol (Coreg) and metoprolol (Lopressor, Toprol XL)

Pacemaker

Another option for some people with abnormal electrocardiograms is a special pacemaker that coordinates the contractions between the left and right ventricle (biventricular pacing). It is a device implanted into the chest to continuously monitor heart rhythm and deliver precisely calibrated electrical shocks when needed to control the abnormal, rapid heartbeats.

•    Hypertrophic cardiomyopathy

Medications

Many doctor may recommend beta blockers such as Lopressor or calcium channel blockers such as Verapamil (Calan, Isoptin), which can relax the patient’s heart.

Pacemaker

For some people, a pacemaker may be recommended.

Operation

In advanced cases of hypertrophic cardiomyopathy, a surgeon may remove a portion of the thickened muscle wall that interferes with normal blood flow.

Alcohol ablation

Your doctor may also recommend a new therapy called alcohol ablation. This non-surgical procedure, which uses injected alcohol to destroy the extra heart muscle, may reduce thickening and improve the blood flow.

•    Restrictive cardiomyopathy

This type of cardiomyopathy can be easily treated. Doctor should recommend the patient to pay careful attention to salt and water intake and monitor weight daily. Fluid retention is treated with diuretics.