title: Where to Q in PEP.
abstract: The onset of ventricular depolarization defines the start of the preejection period (PEP), which is commonly used as an index of myocardial contractility and sympathetic control of the heart. Although the fiducial point for this onset has traditionally been the onset of the Q wave of the electrocardiogram, other measurement points have also been used in the literature, including the peak of the Q wave (i.e., the onset of the R wave). Conceptual, physiological, and empirical considerations addressing the reliability and validity of these alternative metrics support the application of the Q-wave peak/R-wave onset as the fiducial point for PEP measures.
authors.affiliation: Department of Psychology, The Ohio State University, Columbus, Ohio 43210, USA. Berntson@osu.edu
authors.forename: Gary G
authors.initials: GG
authors.lastname: Berntson
authors.forename: David L
authors.initials: DL
authors.lastname: Lozano
authors.forename: Yun-Ju
authors.initials: YJ
authors.lastname: Chen
authors.forename: John T
authors.initials: JT
authors.lastname: Cacioppo
mesh_terms: D000293:Adolescent; D000328:Adult; D002307:Cardiography, Impedance; D004562:Electrocardiography / Q000706:statistics & numerical data*; D004594:Electrophysiology; D005260:Female; D006321:Heart / Q000502:physiology*; D006801:Humans; D008297:Male; D009200:Myocardial Contraction / Q000502:physiology; D015588:Observer Variation; D015203:Reproducibility of Results; D016276:Ventricular Function