Dilated cardiomyopathy is a heart muscle disease where the left ventricle, the heart’s main pumping chamber, becomes enlarged. This stretching and thinning of the ventricular wall weakens the muscle, impairing its ability to effectively pump blood to the body. This condition is the most common type of cardiomyopathy and is more prevalent in men than in women.
The Physical Effects on the Heart
The dilation process can eventually spread from the left ventricle to the right ventricle and the atria. This weakening of the heart’s pumping action is measured by ejection fraction, which is the percentage of blood pumped out of the ventricle with each contraction. In a heart with dilated cardiomyopathy, the ejection fraction is reduced. As the ventricles enlarge, the heart valves may also fail to close properly, causing blood to leak backward.
Causes and Risk Factors
The causes of dilated cardiomyopathy are varied. In many cases, a specific cause cannot be identified, a situation known as idiopathic dilated cardiomyopathy. Genetic factors also play a role, as the condition can be inherited and is referred to as familial dilated cardiomyopathy. It is estimated that about one in 2,500 people are affected by the disease.
Acquired causes result from damage to the heart muscle from external factors. Viral infections that lead to inflammation of the heart muscle can trigger the condition. Chronic excessive alcohol consumption is a well-documented cause, leading to alcoholic cardiomyopathy. Other substances, including certain toxins and illicit drugs like cocaine, can also damage the heart muscle.
Certain medical conditions and circumstances increase the risk of developing dilated cardiomyopathy. These risk factors include:
- Uncontrolled high blood pressure
- Coronary artery disease and previous heart attacks
- Complications during the last month of pregnancy or within five months after birth (peripartum cardiomyopathy)
- Thyroid disease
- Diabetes
Signs and Diagnostic Process
In the early stages, dilated cardiomyopathy may not produce any noticeable signs. As the condition progresses and heart function declines, symptoms appear. One of the most common is fatigue, a sense of persistent tiredness and reduced ability to engage in physical activity. Shortness of breath is also frequent, occurring with exertion or when lying down as fluid accumulates in the lungs.
This fluid buildup, a sign of heart failure, can also cause swelling, known as edema, in the legs, ankles, feet, and abdomen. Some individuals may experience heart palpitations, which feel like a fast, fluttering, or pounding heartbeat. These symptoms arise because the weakened heart cannot adequately circulate blood, leading to fluid retention.
Diagnosing dilated cardiomyopathy involves a physical examination and specialized tests. The primary tool for confirmation is an echocardiogram, an ultrasound that provides detailed images of the heart. This allows a doctor to see the enlarged chambers, assess the thinning of the muscle walls, and measure the ejection fraction. An electrocardiogram (EKG) is also used to detect irregular heart rhythms, while a chest X-ray can reveal the heart’s enlarged size. Blood tests may be ordered to check for infections or other contributing conditions.
Medical Management and Therapies
Treatment for dilated cardiomyopathy focuses on managing symptoms, improving heart function, and preventing the disease from worsening. Medications are a foundational component of this strategy. Drugs like ACE inhibitors and beta-blockers are prescribed to improve the heart’s pumping efficiency and reduce strain. Diuretics are used to help the body eliminate excess fluid, which alleviates swelling and shortness of breath.
Lifestyle modifications are also an important part of the treatment plan. Adopting a low-sodium diet can help control fluid retention and reduce the workload on the heart. For individuals whose condition is linked to alcohol, complete cessation is recommended to prevent further damage. Regular, moderate exercise, as advised by a healthcare provider, can also be beneficial.
In cases where the condition is advanced or does not respond to medication and lifestyle changes, more advanced therapies are considered. For patients at risk of life-threatening irregular heartbeats, an implantable cardioverter-defibrillator (ICD) may be surgically placed. This device monitors the heart’s rhythm and can deliver an electrical shock to restore a normal beat. In the most severe instances of heart failure, a heart transplant may be necessary.
Living with Dilated Cardiomyopathy
Managing dilated cardiomyopathy is a long-term process that requires consistent medical care and monitoring. The condition is chronic, necessitating ongoing attention to maintain stability. Regular follow-up appointments with a cardiologist are a standard part of the management plan. These visits allow the medical team to monitor heart function using repeat echocardiograms and make adjustments to the treatment regimen.
The outlook for individuals with dilated cardiomyopathy is highly variable. Prognosis depends on the underlying cause, the severity of the heart muscle weakness at diagnosis, and how well a person responds to treatment. With early diagnosis and adherence to a comprehensive treatment plan that includes medication and lifestyle adjustments, many people can manage their symptoms and lead active lives.