An electrocardiograph is ECG instrument which records ECG wave and ECG interpretation on a special ECG chart paper. Whereas Electrocardiogram is ECG test report which shows ECG tracing and EKG interpretation recorded on ECG chart paper. ECG graph test reports also known as EKG test report. ECG full form is electrocardiograph or electrocardiogram. Electrocardiogram definition : Electrocardiogram is ECG test report. Electrocardiograph definition : Electrocardiograph is ECG machine/ instrument. The Word EKG (German name) comes from the early 20th-century Greek word kardia. German acronym EKG for Elektrokardiogramm and this represents that Germans physicians were pioneers in the field of medical innovation and ECG is American name of the same EKG.