Sudden Death

Dysrhythmia

An abnormality of heart rhythm.

Tachycardia

Rapid heart rate of 100 beats per minute or more.

Bradycardia

Unusually slow heart rate of 60 beats per minute or less.

Ventricular tachycardia (VT)

Rapid heart rhythm, usually 150–200 beats per minute, originating in the ventricles instead of the atria.

VT effects

Insufficient time for the left ventricle to fill, causing low blood pressure, lost pulse, weakness, light-headedness, or unresponsiveness; may deteriorate into ventricular fibrillation.

Ventricular fibrillation (VF)

Disorganized, ineffective quivering of the ventricles; no blood is pumped and the patient becomes unconscious within seconds.

Defibrillation

The process of delivering an electrical shock to restore a normal heart rhythm; highly effective if given within the first few minutes of sudden death.

CPR during sudden death

If a defibrillator is unavailable, initiate CPR immediately until defibrillation can be performed.

Survival decline without defibrillation

Chances of survival decrease by approximately 10% each minute until defibrillation is accomplished.

Asystole

Complete absence of electrical activity in the heart, often following uncorrected VT or VF; usually fatal without CPR.

Ischemia and asystole

Asystole generally reflects prolonged ischemia, and nearly all patients in asystole die.