Dilated Cardiomyopathy: Causes, Symptoms, and Heart Health Risks

Dilated cardiomyopathy (DCM) is a condition that affects the heart muscle, causing it to become stretched, enlarged, and weakened. As the heart muscle thins and enlarges—most commonly in the left ventricle—the heart loses its ability to pump blood effectively throughout the body.

This condition is one of the most common forms of cardiomyopathy and is an important cause of heart failure in Canada. In many cases, dilated cardiomyopathy can run in families, although it may also develop due to other medical or lifestyle factors.

What Causes Dilated Cardiomyopathy?

In some individuals, no clear cause is identified. In others, dilated cardiomyopathy may be linked to:

• Long-standing or uncontrolled high blood pressure

• Viral infections affecting the heart muscle

• Heart valve disease

• Excessive or long-term alcohol consumption

• Pregnancy-related heart strain (peripartum cardiomyopathy)

• Genetic or inherited conditions

How Dilated Cardiomyopathy Affects the Heart

When the heart muscle stretches and weakens:

• The heart cannot pump blood efficiently
• Blood may back up into the lungs and other organs
• Fluid can accumulate in the lungs, abdomen, ankles, and legs

Over time, this reduced pumping ability places stress on the entire circulatory system and may lead to heart failure or dangerous heart rhythm problems.

Signs and Symptoms of Dilated Cardiomyopathy

Dilated cardiomyopathy often develops gradually, which means symptoms may go unnoticed until the condition becomes advanced.

Common symptoms include:

• Shortness of breath, especially during activity or when lying flat
• Palpitations or irregular heartbeats
• Swelling of the ankles, legs, or abdomen
• Excessive fatigue and reduced exercise tolerance

Some individuals may develop severe symptoms before receiving a diagnosis.

Potential Complications

When dilated cardiomyopathy progresses, it can increase the risk of:

• Blood clots, which may lead to stroke or pulmonary embolism
• Abnormal heart rhythms (arrhythmias)
• Chest pain
• Worsening heart failure

Management and Treatment Options

Although there is no cure for dilated cardiomyopathy, many people can live active lives with proper treatment and monitoring. Management depends on the severity of symptoms and how much the heart is affected.

Treatment may include:

• Medications to control blood pressure, reduce fluid buildup, and manage heart rhythm issues
• Pacemaker therapy to regulate heart rate
• Implantable cardioverter-defibrillator (ICD) for individuals at risk of life-threatening arrhythmias

With ongoing medical care and lifestyle adjustments, many individuals with dilated cardiomyopathy achieve good long-term outcomes.

First Aid & Cardiac Awareness Disclaimer

This information is provided for educational and first aid awareness purposes only and is not a substitute for medical diagnosis or treatment. Dilated cardiomyopathy is a serious heart condition that requires ongoing care from a qualified healthcare professional.

Understanding cardiac symptoms, shortness of breath, and circulatory emergencies is an important part of first aid education. Canadians are encouraged to complete First Aid and CPR training to better recognize and respond to heart-related emergencies.