Family Nurse Practitioner Exam

What is indicated by a heart rate of 170 beats/minute with P waves before each QRS complex?

1. Ventricular tachycardia

2. Paroxysmal atrial tachycardia

3. Atrial fibrillation

4. Ventricular fibrillation

The correct answer is: Paroxysmal atrial tachycardia

A heart rate of 170 beats per minute accompanied by P waves before each QRS complex indicates the presence of paroxysmal atrial tachycardia (PAT). In this rhythm, the rapid heart rate originates from the atria, and the P waves, which represent atrial depolarization, are still visible, suggesting that electrical impulses are being generated from the atria rather than from the ventricles. Paroxysmal atrial tachycardia is characterized by sudden onset and termination, which can occur in episodes. The presence of P waves indicates that the atria are functioning normally, albeit with a rapid firing rate, and the conduction to the ventricles is still effective. This aligns with the nature of PAT, where the AV node conducts the signals from the atria to the ventricles. The conditions listed in the other options do not fit this description. Ventricular tachycardia typically lacks P waves, as it originates from the ventricles. Atrial fibrillation, while it also has a rapid heart rate, is characterized by the absence of distinct P waves and has an irregular ventricular response. Ventricular fibrillation is a life-threatening arrhythmia with chaotic electrical activity that leads to ineffective heart contractions and