A normal ECG shows a regular heart rhythm (sinus rhythm) with a heart rate between 60 and 100 beats per minute (bpm). The intervals (PR interval, QT interval, RR interval) representing the durations of different stages of the heart's electrical activity are all within their normal ranges. Specific normal ranges for these intervals may vary slightly depending on the source and individual factors, but a normal ECG definitively indicates the heart is functioning electrically within a healthy range.
Key Features of a Normal ECG:
- Heart Rate: 60-100 bpm (82 bpm in the example provided). Sources cite ranges such as 60-90 bpm or explicitly state 60-100 bpm as normal.
- Rhythm: Regular sinus rhythm. This indicates the heart's natural pacemaker (the sinoatrial node) is functioning correctly.
- Intervals: The PR, QT, and RR intervals are all within the normal ranges, although the precise normal values for these intervals aren't universally defined across all sources. (See Medscape for more detail on intervals). The duration of ventricular depolarization and repolarization (represented by the QT interval) and the time between heartbeats (RR interval) are key indicators of a normal ECG.
- Absence of Abnormalities: A normal ECG is diagnosed by the absence of any recognized abnormality in the waves, segments, or intervals. (ECGlibrary.com)
Understanding Normal Ranges:
Different resources provide slightly varying normal ranges for specific ECG measurements. These variations can be influenced by factors such as age, sex, and underlying health conditions. For example, a study focused on establishing normal ECG limits for adult Angolans found variations based on gender and age. (PubMed) However, the core principle remains: a normal ECG displays a consistent, regular heartbeat within the typical range, along with normal durations for the various electrical phases.
Further Resources:
For detailed information about ECG interpretation, including normal and abnormal findings, refer to these reputable resources:
