Common Causes of Dilated Cardiomyopathy
Finding a specific cause for an individual case of dilated cardiomyopathy can be difficult, especially if you have multiple risk factors, such as high blood pressure, obesity, coronary artery disease or a family history of dilated cardiomyopathy.
Common causes and risk factors of DCM include:
- Cardiac sarcoidosis: A rare disease in which granulomas (clusters of white blood cells) collect in your heart tissue
- Genetic cardiomyopathy: An inherited genetic change that predisposes you to develop this condition
- Viral cardiomyopathy: A condition in which a virus has caused inflammation in your heart muscle
- Autoimmune or inflammatory cardiomyopathy: Conditions that damage the heart muscle through immune system activity
- Toxic cardiomyopathy: Heart muscle damage caused by certain medications, alcohol, or toxin exposure
- Peripartum cardiomyopathy: A condition that develops in the final month of pregnancy or within months after delivery
Why Choose Houston Methodist for Dilated Cardiomyopathy Care
Dilated cardiomyopathy can be difficult to diagnose, but our board-certified heart failure specialists have the expertise to get you answers. We take a team-based approach to your care, working together to understand your condition, explore your options and build a treatment plan that fits your specific needs and lifestyle.
We also believe that understanding your condition is a key part of managing it. Our team is committed to making sure you feel informed and empowered to take an active role in your own care.
Because DCM can run in families, we use genetic testing and counseling to determine whether your condition has a hereditary component, and to identify family members who may be at risk. Our physician-scientists are also leading the nation in researching the genetics of dilated cardiomyopathy, helping doctors around the world better understand and diagnose this condition.
Signs & Symptoms of Dilated Cardiomyopathy
A person with dilated cardiomyopathy may have no symptoms. Because DCM progresses gradually, many patients are unaware of the condition until it has advanced significantly. When symptoms do appear, they are typically related to the heart failure that can result and should prompt immediate medical evaluation.
Symptoms may include any of the following:
Fatigue
DCM reduces the heart's pumping efficiency, leading to persistent tiredness and the inability to engage in an active lifestyle. Even routine daily tasks may become difficult as the condition progresses.
Shortness of Breath
Shortness of breath is one of the most common symptoms of DCM, occurring during activity or when lying down. It may worsen over time as the heart becomes less effective at circulating blood.
Swelling (Edema)
Swelling in the ankles, legs or feet, and in more advanced cases, abdominal swelling (ascites), can occur when fluid backs up due to the heart's reduced pumping ability.
Weight Gain
Rapid or unexplained weight gain can be a sign of fluid retention caused by worsening heart failure and should be reported to your care team promptly.
Gastrointestinal Symptoms
DCM can cause early satiety, bloating and nausea from abdominal fullness, as well as changes in appetite, all related to fluid buildup and reduced blood flow to the digestive system.
Heart Arrhythmia (Palpitations)
Irregular heartbeat and palpitations are common in DCM and can sometimes be dangerous, increasing the risk of sudden cardiac arrest if left untreated.
Dizziness and Fainting
Dizziness or even fainting can occur when the heart is unable to deliver sufficient blood flow to the brain, particularly during physical exertion. These symptoms should not be ignored.
Types of Dilated Cardiomyopathy
DCM can be categorized based on its underlying cause:
Genetic Dilated Cardiomyopathy (Familial)
Familial dilated cardiomyopathy is caused by inherited gene mutations and accounts for approximately 30–50% of all DCM cases. Family members of someone with genetic DCM should be screened, as they may carry the same mutation.
Non-Genetic Dilated Cardiomyopathy (Acquired)
Acquired dilated cardiomyopathy develops due to external factors such as viral infections, toxin exposure or autoimmune disease, rather than an inherited gene mutation.
Idiopathic Dilated Cardiomyopathy
In many cases, no specific cause can be identified despite thorough testing. This is referred to as idiopathic dilated cardiomyopathy and remains one of the most common presentations.
How Dilated Cardiomyopathy Is Diagnosed
DCM is often detected through routine screening, after a family member is diagnosed, or when symptoms of heart failure prompt further evaluation. Diagnosing dilated cardiomyopathy can be challenging. In fact, it is typically a diagnosis of exclusion, meaning your care team will need to rule out any other potential underlying causes first. At Houston Methodist, our specialists conduct a comprehensive evaluation that may include any of the following:
- Physical exam: A physical exam that includes checking your pulse, listening for a heart murmur or irregular heartbeat, assessing for signs of fluid retention such as swelling in the legs or ankles and feeling for enlargement of the heart.
- Family medical history review: Because DCM can be genetic, your doctor will ask whether anyone in your family has been diagnosed with heart disease or cardiomyopathy and whether anyone has died at an early age from an unknown or cardiac-related condition.
- Echocardiogram: An echo using echocardiography is the primary diagnostic tool for DCM, using sound waves to measure the size and function of the heart's chambers and assess how well the heart is pumping.
- Electrocardiogram (ECG/EKG): An EKG detects electrical abnormalities and arrhythmias commonly associated with DCM.
- Cardiac MRI: A cardiac MRI provides detailed images of heart muscle size, function and tissue characteristics, and can help identify underlying causes such as inflammation or fibrosis.
- Cardiac stress test: A cardiac stress test measures your heart function under exertion, usually performed on a treadmill, to assess how well your heart responds to physical activity and help guide treatment planning.
- Oxygen consumption test (VO2 max): This test measures the amount of oxygen your body uses during peak exercise, providing a precise assessment of your exercise capacity and helping your care team determine the most appropriate course of treatment.
- Cardiac PET Scan: In select cases, a cardiac PET scan may be used to evaluate for inflammation or metabolic causes of DCM, such as sarcoidosis.
- Cardiac catheterization: A cardiac catheterization assesses coronary artery disease as a potential underlying cause of DCM and measures the pressures within the heart.
- Genetic testing and counseling: Genetic testing can confirm a genetic diagnosis and help identify at-risk family members who should be screened.
- Holter monitoring: This wearable device records heart rhythm continuously over 24 hours to 30 days to detect arrhythmias commonly associated with DCM.
- Lab work and specialized testing: Lab work and specialized testing includes bloodwork to assess organ function and help identify underlying or contributing causes of DCM, such as thyroid disease, diabetes, infection or alcohol-related damage.
A Program Dedicated to Treating Cardiomyopathy
Specialists within the Houston Methodist Hypertrophic Cardiomyopathy Program are world-renowned experts in both diagnosing and treating dilated cardiomyopathy (DCM). Our program combines advanced diagnostics, cutting-edge therapies and nationally recognized research to offer patients the most comprehensive DCM care available in the region.