Professional and Linguistic Assessments Board (PLAB) Practice Exam

Which arrhythmia is characterized by a rapid heart rate originating from the atria?

1. Atrial Fibrillation

2. Atrial Flutter

3. Ventricular Tachycardia

4. Sinus Bradycardia

The correct answer is: Atrial Fibrillation

The arrhythmia characterized by a rapid heart rate originating from the atria is atrial fibrillation. In atrial fibrillation, the electrical signals in the atria become disorganized, leading to a rapid and irregular heart rate. This arrhythmia can result in varied heart rates and is associated with a higher risk of stroke due to the potential for blood clots forming in the left atrium as a result of ineffective atrial contractions. In contrast, atrial flutter also originates in the atria but is characterized by a more organized and regular rhythm compared to atrial fibrillation. Ventricular tachycardia originates from the ventricles, presenting a different clinical picture and implications for treatment. Sinus bradycardia, on the other hand, is defined by a slower than normal heart rate originating from the sinus node, which is also not consistent with a rapid heart rate as stated in the question. Thus, atrial fibrillation stands out for its rapid and irregular atrial activity, defining it as the correct answer to this question.