What key vital sign change may indicate an impending stroke in a patient?

An irregular pulse is a key vital sign change that may indicate an impending stroke because it can reflect underlying atrial fibrillation or other cardiac arrhythmias that contribute to the risk of stroke. When the heart beats irregularly, it can lead to the formation of blood clots in the atria, which can subsequently dislodge and travel to the brain, causing a cerebrovascular accident (stroke).

Recognizing an irregular pulse is crucial for early intervention, as it might prompt further evaluation and treatment to reduce the patient's stroke risk. Monitoring heart rhythm is a fundamental aspect of managing stroke patients, as appropriate interventions can significantly alter outcomes.

In contrast, while low blood pressure, high glucose levels, and bradycardia are important vital signs to assess in various medical conditions, they do not directly correlate with the immediate risk of stroke in the same way that an irregular pulse does. Low blood pressure and bradycardia might indicate other underlying health issues or different emergencies, and high glucose levels are more indicative of metabolic issues rather than providing a direct link to stroke risk.