Advanced Cardiovascular Life Support (ACLS) Practice Exam

A patient has a heart rate of 180/min and blood pressure of 110/70 mm Hg. What is the next action to take?

1. Administer adenosine IV

2. Perform a vagal maneuver

3. Provide oxygen therapy

4. Start chest compressions

The correct answer is: Perform a vagal maneuver

In cases of a patient presenting with a heart rate of 180 beats per minute and stable blood pressure, the immediate assessment of the heart rhythm is essential. A heart rate this high typically indicates a tachyarrhythmia, which could be supraventricular tachycardia (SVT) or another form of rapid rhythm. Performing a vagal maneuver is a suitable first action in this scenario because it can help slow down the heart rate and potentially restore normal rhythm without the introduction of pharmacological agents. The vagus nerve plays a significant role in heart rate regulation, and maneuvers such as the Valsalva maneuver or carotid sinus massage can stimulate the vagus nerve. If successful, these maneuvers can terminate SVT and may be performed before considering medications like adenosine or escalating care. While administering oxygen therapy is important in various situations, in this stable patient with an adequate blood pressure, it is not the immediate step unless evidence of hypoxia is present. Similarly, while starting chest compressions is critical in scenarios of cardiac arrest, it is not warranted in this case as the patient is conscious, has stable vital signs, and a rapid heart rate that does not indicate the need for such drastic measures.