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Overview

What Is Cardiomyopathy?

Cardiomyopathy is a disease of the heart muscle that changes its structure or how well it works. The muscle may become enlarged, thickened, stiff, or weakened, making it harder for the heart to pump blood effectively. This cardiomyopathy definition includes inherited conditions, acquired forms linked to other health problems or exposures, and changes that may occur with age. Some people have no symptoms at first, while others develop signs of reduced heart function or abnormal rhythms.

Symptoms

Cardiomyopathy Symptoms

Cardiomyopathy symptoms may develop gradually, appear mainly during activity, or be absent until the condition is more advanced. Symptoms can differ by the type and severity of the heart muscle problem, including in people with hypertrophic cardiomyopathy symptoms.

  • Shortness of breath, especially with activity or when lying down.
  • Fatigue or unusual tiredness that limits daily activities.
  • Swelling of the legs, ankles, feet, or abdomen (edema).
  • Chest discomfort or pressure.
  • A racing, pounding, or irregular heartbeat (palpitations).
  • Dizziness or lightheadedness.
  • Fainting or near-fainting (syncope).
  • Reduced ability to exercise or keep up with usual activities.

Get urgent help

Do not ignore serious symptoms

New fainting, severe trouble breathing, persistent chest pain, or a rapid or irregular heartbeat requires urgent medical assessment. Call emergency services if symptoms are severe, sudden, or worsening.

Causes

Causes and Types of Cardiomyopathy

Cardiomyopathy may result from inherited gene changes, reduced blood flow from coronary artery disease, long-term high blood pressure, inflammation, toxins, metabolic disease, pregnancy-related changes, or an unknown cause. In some people, several factors contribute to the heart muscle changes.

STRUCTURAL TYPES

Dilated cardiomyopathy: the heart chambers enlarge and the muscle becomes weaker.


Hypertrophic cardiomyopathy: the heart muscle becomes unusually thick.


Restrictive cardiomyopathy: the muscle becomes stiff and cannot relax normally.


Arrhythmogenic cardiomyopathy: damaged muscle, often in the right ventricle, can increase the risk of abnormal rhythms.

CAUSE-BASED TERMS

Ischemic cardiomyopathy is mainly related to reduced blood flow from coronary artery disease.


Nonischemic cardiomyopathy has another primary cause, such as inherited disease, inflammation, toxins, or an unknown trigger.


Hypertrophic obstructive cardiomyopathy is a form of hypertrophic cardiomyopathy in which thickened muscle obstructs blood leaving the heart.

Risk Factors

Cardiomyopathy Risk Factors

  • A family history of cardiomyopathy or inherited gene changes can increase risk, including for some forms of hypertrophic cardiomyopathy.
  • Risk may increase with age because heart disease and other conditions become more common over time.
  • Some inherited cardiomyopathies are more common in particular ethnic or population groups.
  • A history of unexplained sudden death or serious rhythm problems in a close relative may indicate inherited risk.
  • Certain genetic syndromes can affect the heart muscle even when a person has few symptoms.
  • Coronary artery disease can damage the heart muscle and contribute to ischemic cardiomyopathy.
  • Long-term high blood pressure makes the heart work harder and may change its structure.
  • Diabetes and obesity can increase cardiovascular strain and the risk of heart muscle disease.
  • Heavy alcohol use or exposure to certain drugs can injure the heart muscle.
  • Some infections and inflammatory conditions can weaken or stiffen the heart.
  • Certain cancer treatments can affect heart muscle function and require medical monitoring.
  • Other conditions, including thyroid or metabolic disorders, may contribute to nonischemic cardiomyopathy.

Family history matters

Ask about family evaluation

A first-degree relative with cardiomyopathy or unexplained sudden death should prompt a discussion with a clinician about family evaluation and possible genetic counseling. Relatives may need screening even if they feel well.

Complications

Cardiomyopathy Complications

  • Heart failure can develop when the heart cannot pump enough blood for the body’s needs.
  • Abnormal heart rhythms may cause palpitations, dizziness, fainting, or sudden cardiac arrest.
  • Blood clots can form in the heart and travel to the brain, causing a stroke.
  • Changes in heart size or pressure can lead to heart valve problems.
  • Increased pressure in the lung arteries can cause pulmonary hypertension.
  • Severe obstruction or impaired pumping can reduce blood flow to the body.
  • Sudden cardiac arrest is a rare but life-threatening complication of some cardiomyopathies.

Emergency symptoms

Get emergency help

Sudden fainting, severe chest pain, collapse, or severe shortness of breath may signal a medical emergency. Call emergency services immediately rather than driving yourself for care.

Diagnosis

How Cardiomyopathy Is Diagnosed

Clinicians combine symptoms, family history, a physical examination, and test results to determine whether cardiomyopathy is present and which type is most likely. The evaluation also helps measure heart function, identify complications, and look for an underlying cause.

  • An electrocardiogram records the heart’s electrical activity and may identify rhythm or conduction changes.
  • An echocardiogram uses ultrasound to assess heart size, muscle thickness, pumping, valves, and blood flow.
  • Chest imaging can show an enlarged heart or signs of fluid in the lungs.
  • Cardiac MRI provides detailed images of heart muscle structure, scarring, and inflammation.
  • Exercise testing or rhythm monitoring can assess symptoms during activity and detect intermittent abnormal rhythms.
  • Blood tests may check heart strain and other conditions affecting the heart muscle.
  • Coronary evaluation can look for blocked arteries when ischemic cardiomyopathy is possible.
  • Genetic testing may be appropriate when inherited cardiomyopathy or a relevant family history is suspected.

Treatment & Management

Cardiomyopathy Treatment and Management

Cardiomyopathy treatment depends on the type, cause, symptoms, heart function, rhythm risk, and other health conditions. Goals include improving circulation, controlling symptoms, protecting the heart, and preventing complications. A cardiologist may adjust treatment over time as the condition changes.

MEDICAL MANAGEMENT

Lifestyle and cause management may include controlling blood pressure, cholesterol, diabetes, and coronary artery disease; avoiding harmful substances; and following individualized activity advice. Medicines may reduce fluid buildup, lower blood pressure, support pumping, control rhythms, or reduce the risk of blood clots.

PROCEDURES AND ADVANCED CARE

Procedures or surgery may improve blood flow, repair valves, or reduce an obstruction. Implanted devices, such as pacemakers or defibrillators, may help manage slow rhythms or protect against dangerous ones. Severe disease may require advanced therapies, including a heart transplant, when appropriate.

  • Take medicines exactly as prescribed and ask before stopping or changing them.
  • Attend follow-up visits so heart function, symptoms, and rhythm risk can be reassessed.
  • Monitor and report changes such as increasing swelling, breathlessness, fainting, or palpitations.
  • Manage blood pressure, cholesterol, diabetes, and other conditions that affect the heart.
  • Limit alcohol or avoid it when your clinician recommends doing so.
  • Discuss safe activity levels with your care team rather than starting or stopping strenuous exercise on your own.

Specialist care

Treatment may need to be specialized

People with hypertrophic obstructive cardiomyopathy may need specialized treatment to reduce obstruction and improve blood flow. Medication and activity changes should be individualized by a cardiologist.

Prevention

Can Cardiomyopathy Be Prevented?

Not all cardiomyopathy can be prevented, especially inherited forms. However, managing cardiovascular risks and avoiding known heart-muscle toxins may reduce the risk of some acquired forms, including some cases of nonischemic and ischemic cardiomyopathy.

  • Control blood pressure and diabetes with lifestyle measures and prescribed treatment.
  • Treat coronary artery disease and follow advice to reduce the risk of heart muscle damage.
  • Avoid tobacco and illicit drugs, which can harm the heart and blood vessels.
  • Limit alcohol and ask a clinician what amount, if any, is safe for you.
  • Maintain a heart-healthy eating pattern and activity routine suited to your health.
  • Follow medical advice during pregnancy if you have heart disease or an increased risk of cardiomyopathy.
  • Discuss heart-protective monitoring with your cancer team when treatments may affect heart muscle.

Outlook and Prognosis

Outlook and Prognosis for Cardiomyopathy

Cardiomyopathy may remain stable and manageable, improve when an underlying cause is treated, or become progressive over time. Prognosis cannot be predicted from the diagnosis alone because different forms, including hypertrophic cardiomyopathy, restrictive cardiomyopathy, and ischemic cardiomyopathy, behave differently. Regular evaluation helps the care team identify changes and adjust treatment.

  • The type and underlying cause of cardiomyopathy influence likely progression and treatment options.
  • Heart-pumping function helps show how well the heart is working.
  • A history of dangerous or frequent abnormal rhythms can affect outlook.
  • The severity and pattern of symptoms provide information about heart function and daily limitations.
  • Response to treatment may indicate whether symptoms and heart performance can be improved.
  • Family history may point to inherited risks that require closer monitoring.
  • Access to specialist follow-up can support early treatment of changes and complications.

When Should You See a Doctor

When Should You See a Doctor?

  • Arrange an appointment for unexplained breathlessness, especially during ordinary activities or when lying down.
  • Seek evaluation for swelling in the legs, ankles, feet, or abdomen.
  • Discuss persistent or unexplained fatigue with a clinician.
  • Make an appointment for recurring palpitations or an irregular heartbeat.
  • Ask for medical advice if you have repeated dizziness or lightheadedness.
  • Arrange prompt evaluation after fainting or nearly fainting.
  • Discuss a noticeable reduction in exercise tolerance or activity level.
  • Tell a clinician if a close relative has cardiomyopathy or unexplained sudden death.

Call emergency services

Know when symptoms are an emergency

Call emergency services for severe or sudden chest pain, severe trouble breathing, collapse, fainting during exertion, or symptoms suggesting cardiac arrest. Do not wait for symptoms to improve on their own.

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