Which rhythms are classified as shockable?

The classification of shockable rhythms is pivotal in advanced life support as it guides the use of defibrillation in cases of cardiac arrest. Ventricular Fibrillation (VF) and Pulseless Ventricular Tachycardia (VT) are the rhythms recognized as shockable.

Ventricular Fibrillation is characterized by chaotic electrical activity in the heart, which results in ineffective quivering rather than coordinated contractions. This prevents effective blood circulation and leads to sudden cardiac arrest. Defibrillation aims to restore a normal rhythm by delivering an electric shock, allowing the heart to regain its ability to contract effectively.

Pulseless Ventricular Tachycardia, like VF, is a rapid heart rhythm that does not produce an effective pulse. The heart is beating too quickly for it to fill properly with blood, which also results in inadequate circulation. Delivering a shock in this situation can disrupt the abnormal rhythm and hopefully restore a normal heartbeat.

Other rhythms such as Asystole and Pulseless Electrical Activity (PEA) are not classified as shockable because in these cases, the electrical activity is either absent (asystole) or present but ineffective (in PEA). Administering a shock would not help in these situations,