Beta Phase: Square45 is currently in beta testing. Expect some features or content to be incomplete or missing.
45

QT Interval and Correction

Represents total ventricular electrical activity (depolarization + repolarization). It is corrected for heart rate using the formula: QTc=QT/sqrt(R)QTc = QT / \text{sqrt}(R).
📜

The statement of the theorem

The total ventricular electrical activity, QTQT, is the time duration from the start of depolarization to the end of repolarization. It is defined by the integral of the transmembrane potential V(t)V(t) over the cardiac cycle: \nQT=trepol−tdepolQT = t_{repol} - t_{depol} \nTo normalize for heart rate, the corrected QT interval, QTcQTc, is calculated using the heart rate RR (in beats per minute): \nQTc=QTR=QT60/TcycleQTc = \frac{QT}{\sqrt{R}} = \frac{QT}{\sqrt{60/T_{cycle}}} \nThis correction assumes a square root relationship between the time constant and the heart rate, ensuring consistency across varying cardiac frequencies.
Source: Wikipedia