title: Interpretation and clinical significance of the QRS axis of the electrocardiogram.
abstract: The frontal plane QRS axis of the standard 12-lead electrocardiogram (ECG) is easily and accurately measured by the clinician. A simple method of estimating this axis is discussed. This axis is age-dependent. We reviewed the literature to determine if evidence exists of an association between an "abnormal" QRS axis and clinically significant myocardial disease. We also examined the literature for clinical correlation of a "normal" QRS axis with the absence of myocardial pathology. We found that although an abnormal QRS axis (falling outside the limits of +30 degrees and +90 degrees) occurs in a small number of normal individuals, its presence should prompt a thorough evaluation of all the parameters of the ECG to look for myocardial disease.
authors.affiliation: Division of Emergency Medicine, Tufts/New England Medical Center, Boston, Massachusetts.
authors.forename: J M
authors.initials: JM
authors.lastname: Stephen
authors.forename: H
authors.initials: H
authors.lastname: Dhindsa
authors.forename: B
authors.initials: B
authors.lastname: Browne
authors.forename: R
authors.initials: R
authors.lastname: Barish
mesh_terms: D009202:Cardiomyopathies / Q000175:diagnosis; D004562:Electrocardiography; D006331:Heart Diseases / Q000175:diagnosis; D006801:Humans