Cardiomyopathy is a disease of the heart muscle that impairs contraction, ultimately reducing the heart’s ability to pump blood.
The heart is an organ consisting of four chambers. It has two atria and two ventricles, on the left and on the right.
Each ventricle serves a specific function. The right ventricle contracts and pushes blood into the pulmonary arteries.
The left ventricle contracts and pushes blood into the aorta. The oxygen-rich blood is then delivered to the organs, muscles and tissues in the body.
There are several types of cardiomyopathy. Dilated cardiomyopathy is the most common, accounting for 60% of cases. In this case, the left ventricle can no longer pump enough blood to meet the body’s needs, resulting in heart failure.
Dilated cardiomyopathy can be caused by several factors that are unrelated to heart attacks. It can be genetic: this accounts for 20 to 30% of cases. It may also result from a viral infection, such as HIV. The virus weakens the heart, which impairs its ability to pump blood.
Other factors can also trigger dilated cardiomyopathy. These include excessive alcohol consumption and drug use, particularly cocaine.
It can also result from medication or treatment, such as chemotherapy, related to other conditions.
In rare cases, dilated cardiomyopathy may be caused by pregnancy, lupus or iron overload.
Finally, extreme stress can lead to a form of dilated cardiomyopathy called Takotsubo cardiomyopathy or broken heart syndrome (see box).
Symptoms
Symptoms can vary greatly. They can include shortness of breath, especially during physical activity.
They can also include excessive fatigue that is not necessarily linked to physical activity. Chest pain at rest and during physical activity can also occur. Finally, some people experience palpitations, the sensation of a rapid or irregular heartbeat.
Edema may also develop, causing swelling in the ankles or legs.
Some people may experience difficulty breathing when lying down, called orthopnea.
Diagnosis
The patient should consult a primary care physician, who will make an initial diagnosis before recommending further examinations.
An electrocardiogram (ECG or EKG) is used to detect arrhythmia and determine which additional tests are required.
Echocardiography is the most reliable tool for detecting myocardial hypertrophy. It is essential for establishing the diagnosis. Magnetic Resonance Imaging (MRI) helps refine the diagnosis by identifying potential causes of heart disease.
Cardiac catheterization can be used to analyze the coronary arteries, which are responsible for vascularizing the heart.
What is an electrocardiogram?
It is a test that records the heart’s electrical activity over a given period of time. It identifies the speed at which the heart is beating (heart rate), whether it is beating normally (heart rhythm) and the effectiveness of the heart muscle. An electrocardiogram is also called an ECG or EKG.
Treatment
Beta-blockers may initially be prescribed to treat dilated cardiomyopathy. Diuretics, which stimulate urine production, and antihypertensives, which reduce heart workload, can also be beneficial.
Medical devices, such as an implantable cardioverter-defibrillator, can be inserted to prevent cardiac arrest.
If neither medication nor medical devices are effective, a heart transplant may be considered.
5 to 8 personnes
Each year, 5 to 8 out of every 10,000 people develop dilated cardiomyopathy.
90%
Nine people out of ten with dilated cardiomyopathy are under 65 years old.
What is an implantable cardioverter-defibrillator?
An implantable cardioverter-defibrillator (ICD), referred to in this article, is a small device connected to leads that are often secured to the heart with screws. It should not be confused with an automated external defibrillator, which is used to revive victims of cardiac arrest.
What is broken heart syndrome?
Behind a poetic name that may seem like an imaginary condition lies a very real form of dilated cardiomyopathy. Also known as Takotsubo syndrome, this relatively unknown condition is triggered by particularly acute physical or psychological stress. It mainly affects women over the age of 50. This syndrome is completely reversible under normal circumstances.
Reviewed and approved by Benjamin Bouyer, MD, Cardiologist at Bordeaux University Hospital (CHU)
