1. What is R-R Interval?

The R-R interval is the time between two consecutive R waves in the QRS complex on an electrocardiogram (ECG). It represents the duration of one cardiac cycle and is used to determine heart rate and rhythm.

2. How Does the Calculator Work?

The calculator uses these simple equations:

Where:

• Heart Rate — Beats per minute (bpm)
• R-R Interval — Time between R waves (seconds)

Explanation: Since heart rate is beats per minute (60 seconds), dividing 60 by the heart rate gives the duration between beats in seconds.

3. Importance of R-R Interval

Details: R-R interval measurement is crucial for assessing heart rhythm, detecting arrhythmias, and evaluating heart rate variability which is an important marker of autonomic nervous system function.

4. Using the Calculator

Tips: Enter either heart rate OR R-R interval (not both) and the calculator will compute the other value. Values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a normal R-R interval?
A: For a heart rate of 60 bpm, R-R interval is 1.0 second. At 75 bpm, it's 0.8 seconds. Normal varies with heart rate.

Q2: How do you measure R-R interval on ECG?
A: Count the number of small squares between R waves (each small square = 0.04 seconds at standard 25mm/s speed).

Q3: What does variable R-R interval indicate?
A: Variable intervals may indicate sinus arrhythmia (normal), atrial fibrillation, or other arrhythmias.

Q4: How does R-R interval relate to heart rate variability?
A: HRV is measured by analyzing variations in R-R intervals over time, reflecting autonomic nervous system activity.

Q5: Can R-R interval detect heart problems?
A: Abnormal patterns may indicate arrhythmias, but clinical correlation is needed for diagnosis.