10/03/2025
EKG vs. ECG ā Why are there two abbreviations for the same heart test?
If youāve ever wondered why some people say ECG and others say EKG, youāre not alone.
Both mean the exact same thing: electrocardiogram, a test that records the electrical activity of the heart.
The story goes back to the early 1900s. Dutch physiologist Willem Einthoven invented the electrocardiogram and even won a Nobel Prize for it.
In English, the abbreviation naturally became ECG.
In German, though, ācardioā is spelled with a K (kardio), so the abbreviation became EKG.
As the test spread worldwide, both versions stuck. In the U.S., doctors often leaned toward EKG for practical reasons.
When writing quickly on prescriptions or chart notes, ECG could easily be confused with EEG, which is the brain test. Using EKG made the letters visually distinct and reduced the chance of dangerous mix-ups.
Thatās why, even today, youāll see both EKG and ECG used interchangeably in medicine, research, and everyday conversations.
Different letters, same test, same mission: keeping hearts healthy.
Fun fact: The original Einthoven string galvanometer was actually quite largeāit took up a whole laboratory table and required heavy weights and water cooling. (Far from the portable devices we have today!)
Sources:
National Library of Medicine (PMC) ā Einthovenās String Galvanometer: The First Electrocardiograph; American Heart Association (Circulation Journal) ā The Electrocardiogram at 100 Years: History and Future
