Causes of Ventricular Fibrillation

The following diseases and pathological conditions may be the cause of the Ventricular Fibrillation development:

• Coronary artery disease – it promotes the development of inadequate blood flow in cardiac muscle;
• Hypertrophic Cardiomyopathy – characterized by the hypertrophy of the left ventricle wall;
• Dilated cardiomyopathy – a myocardial disease characterized by the development of the cardiac cavities enlargement and disturbance of the cardiac systole function causing further progression of systolic dysfunction;
• Valvular heart diseases – they cause the impairment of the ventricular filling as well as of the ventricular emptying;
• Paroxysmal Ventricular Tachycardia.

There are also various Ventricular Fibrillation risk factors that have a negative effect on myocardium:

• Water and electrolyte imbalance. Ventricular Fibrillation happens due to the instant redistribution of the potassium ions (K+) and sodium ions (Na+) between the cells of the myocardium and the intracellular fluid. Rapid increase in concentration of potassium in blood plasma together with the decrease of its level in cells may provoke fibrillation. In case of intracellular hypo-calcemia, the myocardium loses its ability to contract properly. But as soon as the balance of electrolytes is restored at the cellular level, fibrillation stops;
• Acidosis – a disturbance of the acid-base balance which causes a drop in blood pressure and suppression of the cardiac function eventually leading to Ventricular Fibrillation;
• Hypoxia or oxygen starvation – in this state heart becomes more vulnerable, and even the slightest irritation may lead to extrasystole and fibrillation. This complication may occur because of the blood electrolyte imbalance resulting from massive blood transfusions;
• Mechanical irritations of the heart caused by various diagnostic and therapeutic manipulations, such as coronary arteriography;
• Hypothermia – a dangerously low body temperature. If body temperature reaches 28 °C (82 °F), there is a risk of Ventricular Fibrillation development due to the increased myocardial irritability.

Ventricular Fibrillation risk factors include:

• Intoxication with cardiac glycosides as well as side effects caused by the average doses of cardiac glycosides;
• Electric shock caused by contact with a source of electricity. Electric current acts not only in the places of contact with the human body and in the way where it goes through the body, but it also causes reflex action manifesting itself in the disturbance of the normal activity of the cardiovascular and nervous systems, respiration and etc.

Next chapter: Symptoms, tests and diagnosis of ventricular fibrillation