Electrocardiogram
An electrocardiogram is a recording of your heart's electrical activity, shown as a series of waves on a tracing. Each heartbeat generates small electrical signals that the test captures and draws as a line on screen or paper.
The ECG is a quick, painless way to see how your heart's electrical system is behaving, including its rate and rhythm. It's a foundational tool clinicians use to spot a wide range of heart-related patterns, from rhythm irregularities to signs of strain.
There isn't a single high or low number here; instead, an ECG produces a pattern of waves that a trained clinician interprets as a whole. Findings labeled abnormal on a tracing can reflect many things, some harmless and some meaningful, and only a qualified professional can tell them apart in the context of your health.
A tracing described as normal generally means the waves fell within expected shapes and timings, but this is a snapshot and doesn't rule everything out on its own.
Rather than a target value, aim to have any ECG reviewed by a clinician who can read the full tracing alongside your symptoms and history. Reading an ECG is a clinician's job, and automated summaries are never a substitute for that expert eye.
Sources
Educational context only, not medical advice or a diagnosis. Reference ranges vary by lab, age and sex; always discuss your results with a clinician.