The importance of routine QT interval measurement in rhythm interpretation.

When monitoring a patient's cardiac rhythm, the QT interval should be routinely measured. A variety of factors can prolong the QT interval such as drug effects, electrolyte imbalances, acute myocardial infarction, and congenital factors. The biggest risk with prolongation of the QT interval is the development of Torsades de Pointes. One obstacle to the routine measurement of the QT interval is the lack of a standardized and simple approach. The purpose of this article is to detail factors that prolong the QT interval and describe methods used to measure the QT interval.