Heart Electrical Cycle Interval Calculator

Basic Intervals

Normal resting heart rate: 60-100 bpm
Normal range: 120-200 ms
Normal range: 80-120 ms
Normal range varies with heart rate

Additional Information

Results

About Heart Electrical Cycle Intervals

The heart's electrical cycle consists of several key intervals that provide important diagnostic information:

  • PR Interval: Time from P wave onset to QRS complex onset, representing AV conduction time.
  • QRS Duration: Time for ventricular depolarization.
  • QT Interval: Time from QRS onset to T wave end, representing total ventricular activity.
  • RR Interval: Time between consecutive R waves, indicating heart rate.

Note: This calculator is for educational purposes only. Always consult healthcare professionals for medical interpretation of ECG readings.

Normal Ranges

  • PR Interval:
    120-200 ms
    First-degree AV block: >200 ms
  • QRS Duration:
    80-120 ms
    Bundle branch block: >120 ms
  • QT Interval:
    Varies with heart rate
    Use Bazett's formula for QTc
  • Heart Rate:
    60-100 bpm (at rest)

Clinical Significance

  • Abnormal PR: AV conduction disorders
  • Wide QRS: Conduction delays
  • Prolonged QT: Risk of arrhythmias
  • Irregular RR: Rhythm disorders