Table 1.

Selected studies of normal ECG intervals

Study	Population	Year	Patients (n)	ECG acquisition	Sampling rate	Analytic program	Percentiles
Rijnbeek et al.	0 to 16 y; Dutch	2001	Male (944); Female (968)	Cardio Control (Delft, Netherlands)	1200 Hz	MEANSa	2nd, 50th and 98th
Wu et al.	18 to ≥ 60 y; Chinesese	2003	Male (3614); Female (1746)	Cardio Control (Delft, Netherlands)	1200 Hz	MEANSa	2nd, 50th and 98th
Mason et al.	0 to 99 years; Northern America (70%), Europe (21%), Africa (3%), Latin America (3%), and Asia (2%) and Oceania (2%).	2007	Male (14,297); Female (12,201)	MTX-2 (CCSSI); MAC 1200 (GE Medical Systems)	500 Hz	CCSSI	1st, 2nd, 50th, 98th, 99th
Rijnbeek et al.	16 to 89 y; Dutch	2014	Male (7326); Female (6028)	ACTA (ESAOTE, Florence, Italy); Cardio Perfect equipment (Welch Allyn Cardio Control, USA); Megacart (Siemens, Erlangen, Germany)	500 Hz	MEANSa	2nd, 50th and 98th

^aModular ECG Analysis System (MEANS)