What is the normal range for heart rate variability (HRV) during daily recordings?

• A. 10 to 50 ms
• B. 50 to 100 ms
• C. 20 to 200 ms
• D. 200 to 300 ms

Answer: (C)

Heart rate variability (HRV) refers to the fluctuations in time intervals between heartbeats and is an important indicator of autonomic nervous system function and cardiovascular health. The normal range for HRV can vary based on various factors, including age, health status, and individual physiological differences.

In healthy individuals, HRV is typically observed to be in the range of 20 to 200 milliseconds, which allows for a robust assessment of cardiac autonomic modulation. Measurements below this range may indicate reduced autonomic flexibility, while values significantly above it could suggest other underlying issues or responses. Therefore, the range of 20 to 200 ms encompasses a healthy spectrum of heart rate variability that reflects a well-functioning cardiovascular system.

This range is widely accepted in both clinical and research settings, making it a crucial baseline for health assessments, diagnostics, and monitoring the efficacy of interventions in various health conditions.