heart and blood vessel disorders
Ventricular Fibrillation
Introduction
Ventricular fibrillation is a potentially fatal, uncoordinated series of very rapid, ineffective contractions of the ventricles (lower chambers of the heart) caused by many chaotic electrical impulses. Ventricular fibrillation causes unconsciousness in seconds, and if the disorder is not rapidly treated, death follows. Electrocardiography helps determine if the cause of cardiac arrest is ventricular fibrillation. Cardiopulmonary resuscitation (CPR) must be started within a few minutes, and it must be followed by defibrillation (an electrical shock delivered to the chest) to restore normal heart rhythm. (See also Overview of Abnormal Heart Rhythms .) In ventricular fibrillation, the ventricles merely quiver and do not contract in a coordinated way. No blood is pumped from the heart, so ventricular fibrillation is a form of Cardiac Arrest and CPR . It is fatal unless treated immediately. The most common cause of ventricular fibrillation is a heart disorder, particularly inadequate blood flow to the heart muscle due to Overview of Coronary Artery Disease (CAD) , as occurs during a Heart Failure (HF) None Overview of Cardiomyopathy None Shock (very low blood pressure), which can result from coronary artery disease and other disorders Electrical Injuries None Drowning None Long QT Interval Syndromes (which may cause Drugs that affect electrical currents in the heart (such as sodium channel blockers or potassium channel blockers—see table) Brugada syndrome and other Cardiac Channelopathies None 