METHODOLOGICAL APPROACHES TO MEASURING AND ESTIMATING THE DURATION OF QT INTERVAL OF A STANDARD ELECTROCARDIOGRAM

Interpretation of each electrocardiogram should include measurement and evaluation of the QT interval, because both an increase and a decrease in its duration are associated with a risk of polymorphic ventricular tachycardia and sudden cardiac death. This article reflects the methodological approaches to determining, measuring and evaluating the duration of the QT interval, describes the nature of its dependence on gender, age and heart rate of the patient, and also describes a number of indicators calculated on its basis. Recommendations for measuring and evaluating the QT interval of a standard electrocardiogram have been formulated on the basis of the literature analysis.