Certified Cardiovascular Technician Practice Exam

Sinus tachycardia refers to an increased heart rate (typically over 100 beats per minute) originating from the sinus node, and it can occur in response to various physiological and psychological conditions. Among the presented options, fever is a well-documented cause of sinus tachycardia. When the body experiences an elevated temperature due to an infection or illness, it often responds by increasing the heart rate to help meet the increased metabolic demands and to facilitate blood flow to areas that may need more immune response. Emotional stress can also contribute to increased heart rate through heightened sympathetic nervous system activity, but it is not the only factor responsible for sinus tachycardia and may vary significantly depending on the individual’s circumstances. A healthy diet and regular exercise typically support cardiovascular health and are unlikely to cause sinus tachycardia; instead, they generally promote a lower resting heart rate and better heart function in the long run. Therefore, fever stands out as a direct cause of sinus tachycardia among the options, as it distinctly affects the body's homeostasis and triggers a compensatory increase in heart rate.