Dilated cardiomyopathy is a disease of the heart muscle characterized by enlargement (dilation) of one or both ventricles. This enlargement causes the heart muscle to weaken and stretch, making it difficult for it to pump blood efficiently to the rest of the body.
Dilated cardiomyopathy not only affects the heart’s ability to pump blood, but it can also disrupt its normal electrical rhythm, which can lead to arrhythmias. In 20–48% of cases it is a hereditary disease, being more prevalent in men than in women.
This condition can affect people of all ages, although it is more common in young and middle-aged adults. If left untreated, dilated cardiomyopathy can lead to serious complications. Therefore, early diagnosis and proper management are crucial to improving people’s quality of life and survival.
Symptoms of dilated cardiomyopathy
The symptoms of dilated cardiomyopathy can vary greatly from person to person. Some people may not experience any symptoms in the early stages of the disease, while others may notice symptoms from the outset. It is important to remember that the severity and presentation of symptoms can vary. Some of the most common symptoms include:
Shortness of breath, especially during physical activity or when lying down.
Fatigue and generalized weakness.
Swelling in ankles, feet and legs (edema).
Weight gain due to fluid retention.
Dizziness or fainting.
Palpitations or a feeling of fast or irregular heartbeats.
Difficulty breathing during the night (paroxysmal nocturnal dyspnea).
Classification of dilated cardiomyopathy
Dilated cardiomyopathy can be classified into different types according to its cause and presentation:
Idiopathic dilated cardiomyopathy: in this case, the exact cause of the disease is unknown. Despite thorough evaluation, a specific cause cannot be identified.
Familial or genetic dilated cardiomyopathy: this type of dilated cardiomyopathy is caused by inherited genetic mutations that are passed from parents to children. Several associated genes have been identified, and genetic testing can help identify family members at risk.
Ischemic dilated cardiomyopathy: it is the result of coronary artery disease, where reduced blood flow to the heart damages the heart muscle.
Non-ischemic dilated cardiomyopathy: this type of dilated cardiomyopathy is caused by factors other than coronary artery disease, such as viral infections, alcoholism, autoimmune diseases, certain medications, etc.
The classification of dilated cardiomyopathy is important because it can influence the treatment approach and the patient’s prognosis. Identifying the underlying cause of the disease can allow doctors to target treatment more effectively and personalize the care plan for each individual.
Causes of dilated cardiomyopathy
Dilated cardiomyopathy can result from a variety of factors that damage the heart muscle and impair its ability to pump blood efficiently. In some cases, the cause may be clear, while in others, it may be difficult to determine. In general terms, dilated cardiomyopathy can be caused by a variety of factors, including:
Genetics: mutations in genes that control the structure and function of the heart muscle. These mutations can affect the heart’s ability to contract and pump blood efficiently.
Infections: viral, bacterial, or parasitic infections that damage the heart. Some viruses, such as Coxsackie B, can cause inflammation of the heart muscle (myocarditis) which, over time, can lead to dilated cardiomyopathy.
Toxins: exposure to certain drugs, alcohol, or heavy metals. Excessive alcohol consumption over a prolonged period can weaken the heart muscle.
Autoimmune diseases: conditions in which the immune system attacks the heart. Diseases such as lupus or rheumatoid arthritis can damage the heart muscle and cause dilated cardiomyopathy.
Other medical conditions: high blood pressure, thyroid disease, or diabetes. These conditions can put additional pressure on the heart and, over time, weaken the heart muscle.
Cancer treatments: some chemotherapy treatments, radiotherapy, or some immunotherapy treatments can damage the heart’s structure and function.
Although the exact cause of dilated cardiomyopathy is often unknown, there are several factors that can increase the risk of developing this condition. Identifying these risk factors can help people take steps to protect their heart health and be more alert to the possible onset of the disease. Among the most common risk factors are:
Family history of dilated cardiomyopathy or heart failure, suggesting a genetic predisposition.
Excessive alcohol consumption, which can damage the heart muscle over time.
Illicit drug use, such as cocaine or amphetamines, which can have toxic effects on the heart.
Certain infections, such as Lyme disease or HIV, which can affect the heart.
Autoimmune disorders, such as lupus or rheumatoid arthritis, in which the immune system attacks the heart.
Exposure to toxins, such as certain cancer medications, which can damage the heart muscle.
Complications of dilated cardiomyopathy
Dilated cardiomyopathy can have significant health consequences, both in the short and long term. It is important to understand these complications in order to take preventive measures and seek appropriate medical attention. Dilated cardiomyopathy can lead to several serious complications, including
Heart failure: the heart cannot pump enough blood to meet the body’s needs.
Arrhythmias: irregular heart rhythms that can be dangerous.
Blood clots: they can form in the heart and travel to other organs, causing a stroke or pulmonary embolism.
Sudden death: due to malignant ventricular arrhythmias.
If you suspect you may have dilated cardiomyopathy, it is important to consult a doctor immediately. Early diagnosis and treatment can help prevent serious complications and improve your quality of life.
Diagnosis of dilated cardiomyopathy
The diagnosis of dilated cardiomyopathy involves a thorough evaluation to determine whether the heart is enlarged and weakened and to identify the underlying cause. The doctor will use a variety of methods and procedures to arrive at an accurate diagnosis. The diagnosis of dilated cardiomyopathy usually involves a combination of:
Physical examination: the doctor will listen to the heart and lungs and look for signs of swelling in the legs and ankles.
Medical history: the doctor will ask about symptoms, family history and risk factors.
Electrocardiogram (ECG): this test records the electrical activity of the heart and can reveal abnormal heart rhythms, an enlarged heart, or damage to the heart muscle.
Echocardiogram: it uses sound waves to create an image of the heart and assess its size, shape, pumping function, and the presence of structural abnormalities. Echocardiography is a key tool for diagnosing dilated cardiomyopathy and assessing its extent.
Cardiac magnetic resonance imaging (MRI): it uses magnets and radio waves to create detailed images of the heart and can help identify the cause of dilated cardiomyopathy, such as inflammation, scarring, or iron deposits. Cardiac MRI can also provide accurate information about the size and function of the heart chambers.
Blood tests: they can be performed to rule out other medical conditions, assess cardiac function, and look for markers of inflammation or cardiac damage. Brain natriuretic peptide (BNP) levels may be elevated in patients with dilated cardiomyopathy and are used for diagnosis, monitoring, and to assess the severity of heart failure.
Cardiac catheterization: in some cases, it can be performed to measure pressure in the heart chambers, assess blood flow through the coronary arteries, and take tissue samples for biopsy.
Endomyocardial biopsy: a small sample of heart tissue can be taken for examination under a microscope to look for signs of inflammation, infection, or cellular damage. Endomyocardial biopsy can be useful in diagnosing specific causes of dilated cardiomyopathy, such as myocarditis or infiltrative diseases.
Treatment for dilated cardiomyopathy focuses on controlling symptoms, preventing complications, improving heart function, and improving the prognosis for patients. The treatment plan is adapted to the individual needs of each person and may include:
Lifestyle changes: adopting healthy habits such as following a low-sodium diet, exercising regularly, quitting smoking, and limiting alcohol consumption. These changes can help reduce the heart’s workload and improve overall cardiovascular health.
Medications: various types of medications can be prescribed to improve heart function, reduce hospitalizations and mortality, control heart rhythm, and prevent blood clot formation. Some of the most common therapeutic groups are ACE inhibitors (angiotensin-converting enzyme inhibitors) and ARBs (angiotensin II receptor blockers), which help relax blood vessels and reduce blood pressure. In addition, neprilysin inhibitors increase the elimination of sodium and water. Beta-blockers decrease heart rate and blood pressure (thereby reducing the workload of the heart). SGLT2 inhibitors improve the prognosis of patients with heart failure. Aldosterone antagonists block the effects of aldosterone (a hormone that can contribute to fluid retention and cardiac fibrosis). Diuretics help remove excess fluid from the body (thereby reducing swelling and shortness of breath). Anticoagulants prevent the formation of blood clots (thus reducing the risk of stroke and pulmonary embolism). And antiarrhythmics help control cardiac arrhythmias.
Implantable devices: in some cases, implantation of an implantable cardioverter-defibrillator (ICD) may be recommended to prevent sudden death, or a cardiac resynchronization pacemaker may be used to improve the coordination of heartbeats.
Surgery: in severe cases, surgery may be considered to repair or replace damaged heart valves, perform surgical revascularization, or implant a ventricular assist device. Valve replacement is considered when the underlying cause is valvular heart disease. Ventricular assist devices (VADs) are implantable mechanical pumps that help the heart pump blood. A heart transplant may be an option for patients with advanced heart failure who do not respond to other treatments.
Cardiac rehabilitation: a supervised exercise program and education to improve cardiovascular health.
The treatment approach may be multidisciplinary, involving cardiologists, electrophysiologists, cardiac surgeons, and other specialists.
Remember that this article is for informational purposes only and does not replace professional medical advice. If you suspect you have dilated cardiomyopathy, consult a specialist to obtain an accurate diagnosis and an appropriate treatment plan tailored to your needs.
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