Dilated cardiomyopathy is a serious condition in which the heart muscle is weakened and no longer has the strength to pump blood throughout the body. Weakened heart cannot pump much blood, so that more blood remains at this level after each heartbeat. As the larger quantities of blood remains in the lower chambers of the heart (ventricles), they dilate. Over time, the heart muscle loses its shape (dilates) and becomes weaker.
Majority of patients with dilated cardiomyopathy eventually develop heart failure. Heart failure does not mean that the heart stops, but rather is a condition in which the ventricles are unable to pump enough blood in order to fulfill oxygen and nutrients necessary for the body.
In most cases the cause of dilated cardiomyopathy is unknown (primary or idiopathic dilated cardiomyopathy). In some cases it can be inherited from the parents the tendency to develop this disease.
There are specific factors that lead to heart muscle damage and possibly dilated cardiomyopathy, including:
Myocarditis, the heart muscle inflammation because of a viral or a disorder of the immune system; acquired infection with human immunodeficiency virus (HIV) can trigger the development of dilated cardiomyopathy;
Coronary artery disease and myocardial infarction: however, they do not lead to dilated cardiomyopathy in each case;
Excessive consumption of alcohol, illegal drugs like cocaine, or chemotherapeutic drugs like lithium and the toxic metals lead and mercury;
Pregnancy: in rare cases dilated cardiomyopathy develops toward the end of pregnancy or in the first 6 weeks after birth (peripartum cardiomyopathy); peripartum cardiomyopathy is an unknown cause.
Dilated Cardiomyopathy – Symptoms
Initially, the disease may be asymptomatic or with mild symptoms of fatigue and weakness. Eventually it will be heart failure.
Symptoms of the disease may develop gradually, in months or years. In some cases, heart failure develops suddenly, for example after a viral infection or pregnancy.
Symptoms of heart failure gradually developed
Typically, symptoms of heart failure gradually developed may include:
Weakness and fatigue;
Dyspnea (difficulty breathing) and / or wheezing (whistling noise made by the passage of air through narrowed airways) during normal activities or efforts gave no shortness of breath in the past;
Shortness of breath;
Dry cough, irritation, especially when lying down;
Swelling especially in the legs, ankles;
Rapid weight gain caused by water retention;
Increased urination at night;
Abdominal swelling, tenderness or pain, which may result in fluid retention in the body (ascites) and the blood that stagnates at the liver level.
Symptoms of sudden heart failure
In sudden heart failure, fluid retention in the lungs can cause pulmonary edema symptoms, for example:
Severe shortness of breath;
Fast or irregular heartbeats;
Mucous, frothy, pink expectoration.
Sudden heart failure is a medical emergency and requires immediate treatment.
Dilated Cardiomyopathy – Complications
Complications of dilated cardiomyopathy include:
Pulmonary edema, which is rapid fluid retention in the lungs;
Arrhythmias, which are abnormal, heart rhythms that can cause loss of consciousness or sudden death.
Dilated cardiomyopathy is the most common form of cardiomyopathy. Other forms of the disease are restrictive cardiomyopathy, in which the heart muscle becomes stiff and hypertrophic cardiomyopathy, the heart muscle is thickened and cannot relax.
Dilated Cardiomyopathy – Investigations
The first step in the diagnosis of dilated cardiomyopathy is a review of the medical history. The doctor will ask the patient about recent illness, alcohol or drug abuse within the family and other cases of heart disease. Then follows a meticulously physical examination, where it is included a cardiac and pulmonary auscultation with a stethoscope.
Unusual noises called heart murmurs, which may indicate the presence of problems in the cardiac walls or valves;
Pulmonary rales (crackling or babble-like noise) heard at the chest, can signal the presence of fluids in the lungs;
Fluid retention can be noted in the extremities, especially at the legs and neck veins.
Can be done the following tests:
Echocardiogram – it is a test that uses ultrasound waves made by high frequency sounds to form an image of the heart on a television screen; This noninvasive and painless test, it is the best and easiest way for the diagnostic of the dilated cardiomyopathy; echocardiogram, also called echo estimates ejection fraction of the heart, a measurement of the efficiency and functioning of the left ventricle which is the main pumping chamber of the heart; also helps to assess the heart valve function, the shape and thickness of the cardiac wall, which if increased may indicate a dilated cardiomyopathy.
Electrocardiogram – is a heart electrical activity measurement, including any abnormal heart rhythms (arrhythmias) resulting from the dilated cardiomyopathy; it can reveal areas that have been damaged by a heart attack; doctor may use a Holter monitor, a portable electrocardiogram machine type that monitors the electrical activity of the heart over a longer period of time (usually 24 hours); it can be done to check for arrhythmias caused by cardiomyopathy.
Chest x-ray – may show whether the heart is enlarged and if there is fluid in the lungs, signs of cardiac failure.
Ventriculogram with radionuclides – called nuclear scanning, measures the ejection fraction; this is a useful measurement because ejection fraction is decreased in dilated cardiomyopathy; During this test, a small dose of radioactive substance (radionuclide) is injected into a vein; gamma rays emitted by the radioisotope movements are tracked through the cardiac chambers with a gamma camera, and the images are analyzed by a computer.
Coronary angiogram and coronary catheterization – in angiogram or coronary catheterization, a thin tube is inserted through a flexible artery or vein in the arm or groin to the heart to measure the pressure in the heart chambers and to take blood samples; after a contrast substance, it may be injected to see if the arteries that feed the heart (coronary arteries) are blocked, how the blood is pumped into the heart chambers and if blood escapes from the heart valves.
Myocardial biopsy – a sample of heart tissue can be taken by the catheter and examined for signs of infection, metabolic or tumoral diseases; this procedure is usually reserved for patients with acute heart failure who do not respond to treatment.
Electrophysiological study – is another way to study the electrical activity of the heart; is used to evaluate cardiac arrhythmias or syncope and to estimate the risk for sudden cardiac death.
Dilated Cardiomyopathy – Treatment
In most cases, treatment for dilated cardiomyopathy is performed to relieve the symptoms, improve the cardiac function and prolong life. Most patients will require a number of medications along with lifestyle changes. Surgical procedures will also be considered, especially when medication does not improve the patient’s condition.
In some cases, the causes of this condition can be successfully removed, such as dilated cardiomyopathy caused by excessive alcohol consumption. Limiting alcohol consumption may help prevent the diseases progression.
However, viral myocarditis (inflammation of heart muscle caused by a virus), there are no medications to treat viruses that cause the appearance of the dilated cardiomyopathy.
Medicines used for heart failure determined by dilated cardiomyopathy are:
Converting enzyme inhibitors (ACE inhibitors) and vasodilators that enlarge the diameter of blood vessels to improve the blood flow and to reduce the cardiac filling; ACE inhibitors are considered the basis therapy for dilated cardiomyopathy; has been shown that they improve symptoms and prolong life in patients with heart failure (other vasodilators are used only when ACE inhibitors cannot be administered);
Beta-blockers, which slow down the heart rate and reduce the blood pressure: the heart can pump more efficiently when you have more time to relax; carvedilol and metoprolol are approved beta-blockers for heart failure treatment; studies show that adding beta-blockers to standard therapy with ACE inhibitors may reduce the rate of hospitalization or death in patients with moderate or severe insufficiency;
Diuretics to help to remove the fluid in excess from the body; Spironolactone is a diuretic that prevents potassium loss and has been shown to prolong life in patients with severe heart failure;
Inotrope such as the digoxin or digitoxin, which stimulates muscle contractility, improve blood flow and reduce symptoms of heart failure;
Anticoagulants, such as warfarin and heparin, in order to prevent the blood clotting that can occur when the blood is not pumped efficiently in the heart and throughout the body; thrombi (clots) of blood can lead to stroke or heart attack; patients with dilated cardiomyopathy and atrial fibrillation are at increased risk of developing blood clot;
Antiarrhythmic such as Amiodarone controls the heart rate when rapid, abnormal rate is present (arrhythmia).
A pacemaker may be surgically placed in the upper chest to control potentially fatal abnormal heart rhythms (arrhythmias). Bicameral pacemaker that stimulate the both ventricles (the two-chamber pacing); or the both ventricles and the right atrium (AV sequential pacing) are now more commonly used for this condition.
Implantable cardioversion defibrillators are recommended in patients with risk of ventricular tachycardia, a life-threatening arrhythmia or cardiac arrest. A recent study suggests that cardiac resynchronization therapy, which uses a pacemaker and sometimes implantable cardioversion defibrillators to stimulate the heart and to restore the normal heart rhythm and function; they reduce the risk of death by heart failure.
Experimental surgical procedures may be considered in patients with dilated cardiomyopathy, especially in those who cannot quickly receive a heart transplant and have no other treatment options.
Experimental surgical procedures that are not considered standard treatment, but have potential for the future include:
Surgical ventricular restoration , in which the heart portions that have been weakened and damaged by a heart attack are removed surgically to improve cardiac pump function;
Dynamic Cardiomyoplasty, where a section of a skeletal muscle or an artificial elastic mesh is surgically placed around the heart to improve the pumping ability of the heart and prevents its further expansion;
Surgical implantation of a ventricular mechanical device that helps the heart to pump more blood; these devices are used temporarily until cardiac transplantation is possible (intermediate treatment). Are also studied as an alternative to heart transplantation for a long-term treatment of severe heart failure. These devices require surgery to be positioned and made the necessary connections between the heart and the device.
Heart transplantation is required in patients who:
Do not respond to medication or the medication has lost its effect in time;
Have impaired blood circulation and major organ failure due to heart failure.
Heart transplantation is very complex procedures that involves surgical removal of the damaged heart and replace it with a new healthy heart from a donor. There is a limited number of hearts available, and applications for a heart transplant are very specific.
Outpatient treatment (at home)
While medical treatment is very important in dilated cardiomyopathy, the following recommendations of conduct are also important:
Avoid alcohol: excess in alcohol can increase the risk of long-term development of cardiomyopathy in some people;
Restriction of salt in the diet: the body tries to compensate for heart failure by retaining salt and water, this leading to edema; sodium intake will be maintained around 2000 mg per day; many cooked foods are high in sodium and should be avoided, for example chips, salted pretzels, salted nuts, cooked meats, cheese, pizza, canned soups, vegetables, olives, meals from the fast food, prepared foods frozen (except those labeled low sodium);
Must be consumed fruits and vegetables instead of canned foods;
Avoid ingestion of large amounts of water to control water retention; doctor will instruct the patient about the specific fluid needs of the disease;
The patient will weigh daily, the weight will increase in case of rapid fluid retention; doctor should be informed when the patient has gained weight between 1.3 kg and 1.8 kg in two days;
Physical exercises: the doctor will instruct the patient to the types of exercises that can be performed without appearing any complications; they will be encouraged to walk, to cycle or to do other types of movement, if the condition allows it.
Pregnancy can be dangerous in combination with dilated cardiomyopathy. Patients with this condition who desire a pregnancy will consult a doctor about it.