Paroxysmal atrial tachycardia is characterized by which of the following?

• A. Slow sinus rhythm
• B. Atrial fibrillation with irregular rate
• C. Persistent ventricular tachycardia
• D. A supraventricular rhythm with abrupt onset and termination

Answer: (D)

The key idea is that paroxysmal atrial tachycardia is a sudden, self-terminating fast rhythm that comes from atrial tissue above the ventricles. It presents as a rapid, regular supraventricular tachycardia that starts abruptly and ends abruptly, without a gradual slowing. On the ECG, if the ventricles conduct normally, the QRS complexes are narrow. This distinguishes it from slow sinus rhythm (not tachycardia), atrial fibrillation (irregularly irregular rhythm with variable rate), and ventricular tachycardia (originates in the ventricles and usually has a wider QRS).