[Comparison of QT-Interval Measurement Techniques and Their Clinical Value]

Long QT-interval is one of most important predictors of risk of development of life threatening arrhythmias and sudden death. Correct measurement of QT-interval is essential for diagnosis of its prolongation. At present the Bazett formula for calculation of corrected QT (QT(c) = QT/ radical (RR)) is a standard method of QT estimation. However historically in Russia calculation of predicted QT (QT(k) = k radical (RR)) QT(k) has become an accepted technique. Furthermore many authors in this country apply criteria created for QT(c) for interpretation of QT(k) values. This results in hyperdiagnosis of QT prolongation in unaffected persons, erroneous conclusions on harmless nature of this condition, and underestimation of risk in patients with real long QT syndrome. Thus it is vital to proclaim calculation of QT(c) an obligatory standard and to use existing international criteria for its interpretation.