Ventricular Fibrillation is one of the most dangerous types of cardiac arrhythmia. It is a rhythm disturbance characterized by atactic asynchronous contractions of certain muscle fibers of the ventricles. Blood circulation stops and clinical death occur in the absence of ventricular systole.
It is a chaotic irregular twitching of certain fibers of the heart muscle. If you look at such a heart, it may seem as it is trembling or fluttering. In its consequences fibrillation is equal to cardiac arrest. Ventricular Fibrillation is an extremely serious condition which leads to the cessation of the blood flow to the brain and heart vessels and results in instant death. As a rule Ventricular Fibrillation is a complication of an extensive myocardial infarction and causes sudden cardiac death.
Ventricular Fibrillation is most common in people between 45 and 75 years of age. Males suffer from this condition three times more often than females. Fibrillation is one of the common causes of sudden death (70%) in patients with acute myocardial infarction, coronary artery disease, hypertension, myocarditis and heart defects.
It is a common practice to divide Ventricular Fibrillation into three conventional types:
- Primary Ventricular Fibrillation – it develops within 24-48 hours after the start of myocardial infarction and reflects the electrical instability of the myocardium provoked by acute ischemia. It is the main cause of sudden death in patients with myocardial infraction. 60% of fibrillation cases develop within the first 4 hours, and 85% - within 12 hours from the onset of infarction;
- Secondary Ventricular Fibrillation – it occurs in the setting of cardiogenic shock (a sudden decrease in cardiac contractile function and drop in blood pressure as a result of a heart damage) caused by myocardial infarction and may result in the death of a patient;
- Late Ventricular Fibrillation – it occurs after 48 hours from the onset of the myocardial infarction, as a rule it happens on the 2nd–6th week of the disease. The death rate due to the late fibrillation developed in the setting of infarction is over 60%.