The normal ranges of electrocardiographic interval values are poorly understood.  The purpose of this Web Page is to provide a reliable set of normal values for use in research and education.  These values are published*.  Due to lack of large enough datasets derived from diverse demographics, previous normal ranges for the ECG have inadequately or inaccurately accounted for the large variations or normal based upon age and sex.  The tables accessible below were derived from 79,743 subjects screened for participation in pharmaceutical clinical trials.  The ECGs were measured and interpreted by US board certified cardiologists using a high-resolution digital ECG viewing device.  The tables provide various levels of detail and demographic.

*Mason JW, Ramseth DJ, Chanter DO, Moon TE, Goodman DB, Mendzelevski B. Electrocardiographic reference ranges derived from 79,743 ambulatory subjects. J Electrocardiol 40:228-234, 2007


Click for Summary Table, HR, PR, QRS, QRS axis

Under construction: more tables to be added

ALL 79,743 SUBJECTS (including normal and disease populations)

Under construction: more tables to be added

ECG Normal Values

Jay W. Mason, MD