1. What is the RR Interval?

The RR interval is the time between successive R waves of the QRS complex on the electrocardiogram (ECG). It represents the duration of the cardiac cycle and is inversely related to heart rate.

2. How Does the Calculator Work?

The calculator uses the simple formula:

Where:

• \( RR \) — RR interval in seconds
• \( HR \) — Heart rate in beats per minute (bpm)

Explanation: Since there are 60 seconds in a minute, dividing by heart rate gives the duration of each cardiac cycle.

3. Importance of RR Interval Calculation

Details: The RR interval is fundamental in ECG analysis, used for assessing heart rate variability, diagnosing arrhythmias, and evaluating autonomic nervous system function.

4. Using the Calculator

Tips: Enter heart rate in beats per minute (bpm). Value must be valid (HR > 0).

5. Frequently Asked Questions (FAQ)

Q1: Why is RR interval important?
A: It helps assess cardiac rhythm, detect arrhythmias, and evaluate autonomic nervous system function through heart rate variability analysis.

Q2: What are normal RR interval values?
A: Normal varies with heart rate. At 60 bpm, RR is 1.0 second; at 75 bpm, 0.8 seconds; at 100 bpm, 0.6 seconds.

Q3: How is RR interval measured on ECG?
A: It's measured from the peak of one R wave to the peak of the next R wave, typically in milliseconds.

Q4: Does blood pressure affect RR interval?
A: While blood pressure doesn't directly enter this calculation, autonomic responses to BP changes can affect heart rate and thus RR interval.

Q5: What does a variable RR interval indicate?
A: Variable RR intervals may indicate sinus arrhythmia (normal in young people) or pathological arrhythmias like atrial fibrillation.