Atlas of Medicine

Diagnostic technology · reviewed

Electrocardiography

Clinically practical from 1903
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An electrocardiogram records voltage changes produced by the heart over time.

Earlier investigators detected cardiac electricity, but Einthoven's string galvanometer and standardized interpretation made reproducible clinical electrocardiography practical in the early twentieth century. The waveform reflects the ordered electrical activation and recovery of the heart's chambers. Clinicians use its timing and shape to recognize rhythm disturbances, conduction problems, and signs of cardiac injury, making the ECG one of medicine's most widely used diagnostic tests.

Sources

BioelectricityWillem EinthovenVacuum tubeImplantable pacema…Electrocardiographytechnology
Concept map · prerequisites lead toward this node; descendants continue outward.
Thomas Lewis’s historical electrocardiograph
An electrocardiograph used by cardiologist Thomas Lewis in Cambridge around 1930. Unknown creator. CC BY 4.0. Wikimedia Commons.

Direct relationships

  1. Bioelectricity→ElectrocardiographyEstablished cardiac electrical activity as a measurable signal · high confidence
  2. Willem Einthoven→ElectrocardiographyMade electrocardiography accurate, standardized, and clinically interpretable · high confidence
  3. Vacuum tube→ElectrocardiographyLater enabled electronic amplification of cardiac signals · low confidence
  4. Electrocardiography→Implantable pacemakerLinked rhythm diagnosis with electrically timed treatment · medium confidence