Cardiac arrest

Cardiac arrest occurs when the heart stops beating. It is defined as cessation of normal circulation of blood due to failure of the heart to pump effectively. It is a medical emergency that, without immediate medical intervention, will result in cardiac death within minutes. When it happens suddenly, it is called sudden cardiac arrest. Cardiopulmonary resuscitation (CPR) and possibly defibrillation are needed until further treatment can be provided. Cardiac arrest results in a rapid loss of consciousness, and breathing may be abnormal or absent. Coma can occur as a result of the cardiac arrest when the brain goes too long without oxygen. While cardiac arrest may be caused by heart attack or heart failure, these are not the same, and in 15 to 25% of cases, there is a non-cardiac cause. Some individuals may experience chest pain, shortness of breath, nausea, an elevated heart rate, and a light-headed feeling immediately before entering cardiac arrest. The most common cause of cardiac arrest is an underlying heart problem like coronary artery disease that decreases the amount of oxygenated blood supplying the heart muscle. This, in turn, damages the structure of the muscle, which can alter its function. These changes can, over time, cause ventricular fibrillation (V-fib), which most commonly precedes cardiac arrest. Less common causes include major blood loss, lack of oxygen, very low potassium, electrical injury, heart failure, inherited heart arrhythmias, and intense physical exercise. Cardiac arrest is diagnosed by the inability to find a pulse. CPR and defibrillation can reverse a cardiac arrest, leading to return of spontaneous circulation (ROSC), but without such intervention, it will prove fatal. In some cases, cardiac arrest is an anticipated outcome of serious illnesses where death is expected. Treatment for cardiac arrest includes immediate CPR and, if a shockable rhythm is present, defibrillation. Two protocols have been established for CPR: basic life support (BLS) and advanced cardiac life support (ACLS).