What is cardiac arrest?
The heart is a muscle, a pump powered by electrical tissue, which enables it to contract to eject 5 liters of blood per minute into the arteries. Cardiac arrest is a mechanical stop of the heart that has an electrophysiological origin (electrical dysfunction of the heart rhythm). It results in the suspension of blood circulation and the interruption of the blood supply (and therefore oxygen) to vital organs, notably the brain. The victim loses consciousness and does not respond to verbal or painful stimuli.
Cardiac arrest is not a disease in itself, but rather a complication of another pathology, such as myocardial infarction, heart disease, cardiac rhythm disorders... It is the primary disease that manifests itself through warning signs, hence the importance of knowing and recognizing typical and atypical symptoms.
Stopped breathing is one of the signs of cardiac arrest: if the chest stops rising, the heart stops beating, and you need to intervene very quickly. It all comes down to the first five minutes. After 5 minutes, cardiac arrest causes irreversible brain damage. And after 12 minutes, death ensues. The majority of survivors suffer after-effects, particularly neurological (see Agir : les 5 maillons de la survie - link).
Cardiac arrest can have several causes
.
- Myocardial infarction. A coronary artery -which supplies blood to the heart- becomes blocked. The heart muscle no longer receives oxygen, and its cells gradually die until the artery is unblocked. This causes serious ventricular rhythm disorders (tachycardia, then ventricular fibrillation), leading to cardiac arrest.
- cardiomyopathy (hypertrophy of the heart, arrhythmogenic dysplasia of the right ventricle, dilated cardiomyopathy, etc.);
- heart failure
- Congenital anomaly of the heart;
- myocarditis (heart infection)
- massive pulmonary embolism
- Digestive hemorrhage;
- Trauma. A violent blow to the chest at any time during the cardiac cycle can cause ventricular fibrillation followed by cardiac arrest.
- Metabolic or electrolyte disorders (such as low potassium levels in the blood);
- Various acute respiratory disorders such as airway obstruction, drowning, infection, smoke inhalation... ;
- Intoxication (e.g. drug overdose, doping).
- massive stroke
Who can go into cardiac arrest?
Some people are at greater risk of cardiac arrest. People who :
- have already had a myocardial infarction or cardiac arrest ;
- suffer from heart failure ;
- have a family history of cardiac arrest;
- have a heart or respiratory disease that could lead to cardiac arrest.
Further information:
"Women and cardiac arrest what if it were you?"