Final answer:
The two types of life-threatening arrhythmias that cause cardiac arrest are ventricular fibrillation and ventricular tachycardia, both of which disrupt the heart's ability to pump blood and can be treated with defibrillation.
Step-by-step explanation:
The Two Types of Life-Threatening Arrhythmias
In the context of cardiac emergencies, two types of life-threatening arrhythmias that often lead to cardiac arrest are ventricular fibrillation (VF) and ventricular tachycardia (VT). These arrhythmias disrupt the normal electrical activity of the heart. Ventricular fibrillation is a condition where the heart's ventricles beat in a rapid, erratic pattern, rendering the heart unable to pump blood effectively, rapidly leading to brain death if not treated.
Ventricular tachycardia is a fast but regular beating of the ventricles that can also degrade into ventricular fibrillation or result in diminished blood flow. Both of these conditions may be treated with the use of a defibrillator, which delivers a therapeutic dose of electrical energy to the heart, with the aim of stopping the arrhythmia and allowing the heart's natural pacemaker to resume normal rhythm.