The myocardium (from myo, from the ancient Greek “mus” meaning muscle, and card, from the ancient Greek “kardia” meaning heart) constitutes the muscular part of the heart.

Position. The myocardium is one of the structures of the heart wall. It is located between two layers: the pericardium which envelops it from the outside, and the endocardium which lines it from the inside (1).

Structure. The myocardium is a thick-layered muscle made up of striated muscle fibers. These fibers are short and interconnected by complex junctions, the intermediate discs (2). Oblique interactions also take place between neighboring fibers. These junctions and interactions give the complex three-dimensional structure of the myocardium. The latter differs from the parallel structure of skeletal muscle fibers, most of which are found in the muscles of the body.

Operation. The muscle fibers of the myocardium function autonomously. Unlike skeletal muscles, the myocardium is controlled by the autonomic nervous system, resulting in involuntary, spontaneous and rhythmic contractions (3).

Vascularization. The myocardium is supplied by the coronary arteries.

Blood propulsion. The contractions of the myocardium allow the circulation of blood within the body.

Myocardial infarction. Also called heart attack, myocardial infarction corresponds to the destruction of part of the myocardium. The cause of this pathology is the obstruction of a coronary artery supplying the myocardium. Deprived of oxygen, myocardial cells die and degrade. This destruction results in a dysfunction of the cardiac contraction which can lead to the stop of the heart. A myocardial infarction is manifested in particular by abnormal heart rhythms or heart failure (4).

Angina pectoris. Also called angina, angina pectoris corresponds to an oppressive and deep pain in the thorax. It occurs most often during exertion but can also appear during periods of stress and more rarely at rest. The cause of this pain is an inadequate supply of oxygen to the myocardium. This is often due to pathologies affecting the coronary arteries, responsible for the irrigation of the myocardium (5).

Thrombolysis. This test consists of breaking up the thrombi, or blood clots, using drugs. This treatment is used during myocardial infarction. (4)

Surgical treatment. Depending on the pathology and its stage of development, a surgical intervention may be implemented. In the event of a myocardial infarction, angioplasty may in particular be performed.

Medical treatment. Depending on the pathology diagnosed, drugs may be prescribed such as anticoagulants, antiaggregants, or even anti-ischemic agents.

Physical examination. First, a clinical examination is carried out in order to assess the pain perceived by the patient and to measure the heart rate.

Electrocardiogram. This test allows you to analyze the electrical activity of the heart.

Stress electrocardiogram. This test is used to analyze the electrical activity of the heart during physical exertion.

Medical imaging examination: A cardiac ultrasound, a Doppler ultrasound, a coronary angiography, a CT scan, a cardiac scintigraphy, or an MRI may be performed.

20th century South African surgeon Christiaan Barnard is famous for performing the first successful heart transplant. In 1967, he transplanted a heart from a young woman who died in a car accident to a man with coronary artery disease. This patient survived after the operation but died 18 days later from pneumonia6. Since this first successful transplant, medical progress has continued as evidenced by recent experiments with transplants from an artificial heart.