American Lifeguard Practice Exam

An abnormal heart rhythm characterized by very rapid contractions of the ventricles is called what?

1. Fibrillation

2. Bradycardia

3. Atrial flutter

4. Ventricular tachycardia

The correct answer is: Ventricular tachycardia

Ventricular tachycardia is the term used to describe an abnormal heart rhythm that features very rapid contractions of the ventricles, typically exceeding 100 beats per minute. This condition occurs when the electrical signals in the heart become disrupted, causing the ventricles to beat faster than they should. It can be particularly dangerous because if it progresses, it may lead to more severe forms of arrhythmia or even cardiac arrest. Fibrillation, while also involving rapid heart contractions, refers specifically to a chaotic and uncoordinated rhythm, most commonly seen in ventricular fibrillation. It is characterized by ineffective quivering of the heart muscle fibers, which does not effectively pump blood. Bradycardia is characterized by a slower than normal heart rate, usually fewer than 60 beats per minute, which is the opposite of what is described in the question. Atrial flutter involves a rapid but organized electrical circuit in the atria, causing them to beat more quickly than usual, but it does not describe the rapid contractions of the ventricles specifically. Thus, the correct identification of ventricular tachycardia is essential in understanding how to respond to this type of cardiac emergency and differentiates it from other arrhythmias.