4.9 of 7 Ratings
Paramedics respond to a call regarding an 18-year-old male with severe sudden-onset heart palpitations. The patient reports symptoms of chest pain, fatigue, and dizziness. Upon examination, his heart rate is 175/min and regular. His blood pressure is 110/75 mm Hg. Gentle massage below the level of the left mandible elicits an immediate improvement in the patient, as his heart rate returns to 70/min. What was the mechanism of action of this maneuver?
Increasing the refractory period in ventricular myocytes
Increasing sympathetic tone in systemic arteries
Decreasing the length of phase 4 of the SA node myocytes
Slowing conduction in the AV node
Decreasing the firing rate of carotid baroreceptors
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