What is the primary concern if a nurse inadvertently massages the carotid sinus during palpation?

When a nurse inadvertently massages the carotid sinus during palpation, the primary concern is severe bradycardia leading to cardiac arrest. The carotid sinus is a sensitive area that contains baroreceptors responsible for monitoring blood pressure. When these receptors are stimulated—such as through massage or excessive pressure—there can be a profound reflex response that affects heart rate.

This reflex can trigger the vagus nerve to increase parasympathetic activity, which significantly slows the heart rate, potentially leading to severe bradycardia. In extreme cases, this could result in cardiac arrest if the heart rate drops significantly enough to compromise circulation.

Understanding the physiology behind this response is essential for healthcare providers. While other options may suggest other potential issues, the direct physiological response to manipulation of the carotid sinus strongly supports the concern of severe bradycardia and its serious consequences.