Cardiomyopathy is a term that can refer to different diseases that affect how the heart muscle works. Dilated cardiomyopathy and hypertrophic cardiomyopathy are the two most common forms. Appropriate management is necessary because they can be life-threatening.

Definition of cardiomyopathy

Cardiomyopathy is a medical term that groups together a set of diseases of the myocardium. The functioning of the heart muscle is affected. Cardiomyopathies have certain points in common but also several differences.

Types of cardiomyopathies

The two most common cardiomyopathies are:

• dilated cardiomyopathy which is characterized by dilation of the chambers of the heart, and in particular of the left ventricle: the heart muscle weakens and no longer has enough strength to pump blood;
• hypertrophic cardiomyopathy which is a genetic disease characterized by thickening of the heart muscle: the heart has to work harder in order to successfully propel the same volume of blood.

More rarely, other types of cardiomyopathy can occur:

• restrictive cardiomyopathy with a heart muscle that stiffens and loses flexibility: the ventricles of the heart have difficulty relaxing and filling properly with blood;
• arrhythmogenic cardiomyopathy of the right ventricle which is characterized by the emission of disordered electrical signals.

Causes of cardiomyopathy

In some cases, cardiomyopathy has no known cause. It is said to be idiopathic.

In the other cases, several causes are possible.

These include in particular:

• a genetic origin;
• other cardiovascular disease such as congenital heart disease, valve disease or chronic hypertension;
• a heart attack that damaged the myocardium;
• a viral or bacterial infection in the heart;
• metabolic diseases or disorders such as diabetes;
• nutritional deficiencies;
• drug use;
• excessive alcohol consumption.

Diagnosis of cardiomyopathy

The diagnosis is initially based on a clinical examination. The healthcare professional assesses perceived symptoms but is also interested in individual and family medical history.

Additional examinations are performed to confirm and deepen the diagnosis of cardiomyopathy. The healthcare professional can rely on several examinations:

• a chest x-ray to analyze the size and shape of the heart;
• an electrocardiogram to record the electrical activity of the heart;
• an echocardiogram to determine the volume of blood pumped by the heart;
• cardiac catheterization to detect certain heart problems (blocked or narrowed blood vessels, etc.);
• treadmill stress tests to assess heart function;
• blood tests.

At first, cardiomyopathy may remain invisible.

When cardiomyopathy worsens, the functioning of the myocardium is increasingly affected. The heart muscle weakens.

Several signs of weakness can be observed:

• tiredness ;
• shortness of breath on exertion, including during usual activities;
• pallor;
• dizziness;
• dizziness ;
• fainting

Heart palpitations

Some cardiomyopathies can lead to cardiac arrhythmia. This is characterized by abnormal, disordered and irregular heartbeats. 

Chest pain

Pain in the chest, or chest pain, may be felt. It should not be neglected because it can indicate a cardiovascular complication. Any pain in the chest requires medical advice.

Several signs should alert:

• the pain is sudden, intense and tightens the chest;
• the pain lasts more than five minutes and does not go away with rest;
• the pain does not go away spontaneously or after taking trinitrin in people being treated for angina pectoris;
• the pain radiates to the jaw, left arm, back, neck or abdomen.
• the pain is more severe when breathing;
• the pain is accompanied by fatigue, weakness, shortness of breath, pallor, sweating, nausea, anxiety, dizziness, even fainting;
• the pain is accompanied by an irregular or rapid rhythm.

Risk of complications

Cardiomyopathy can be the cause of a myocardial infarction, or heart attack. It is a vital emergency.

The therapeutic choices depend on many parameters including the type of cardiomyopathy, its cause, its evolution and the condition of the person concerned.

Depending on the case, the treatment of cardiomyopathy can be based on one or more approaches:

• lifestyle changes which may in particular involve a dietitian or nutritionist;
• drug treatment which can have many goals: lower blood pressure, help relax blood vessels, slow heart rate, maintain normal heart rate, increase the heart’s pumping capacity, prevent blood clots and / or promote the elimination of excess fluid in the body;
• implantation of a pacemaker or an automatic implantable defibrillator (ICD);
• a surgical intervention which can be a heart transplant in the most serious cases.

Prevention is primarily based on maintaining a healthy lifestyle:

• eat a healthy and balanced diet;
• avoid or fight against overweight;
• engage in regular physical activity;
• not to smoke, or to quit smoking;
• limit alcohol consumption;
• follow medical recommendations;
• etc.