As a domain expert in medical terminology and diagnostics, I can provide you with an accurate definition of QTC. A QTC, which stands for QT Corrected or QT Interval Corrected, is a measurement used in cardiology to assess the time between the start of the Q wave and the end of the T wave in the heart's electrical cycle. This interval is typically measured on an electrocardiogram (ECG) and is corrected for heart rate variability using a formula that adjusts the QT interval to a standard heart rate of 60 beats per minute (bpm). The most common formula used for this correction is the Bazett's formula: QTC = QT / (RR^0.5), where RR is the time between two consecutive R waves in the ECG. The QTC is important because it reflects the duration of the ventricular depolarization and repolarization phases, which are critical for the proper functioning of the heart. An abnormally long QTC interval can indicate a risk for a potentially life-threatening heart rhythm disorder known as torsades de pointes, which can lead to sudden cardiac arrest. read more >>

In cardiology, the QT interval is a measure of the time between the start of the Q wave and the end of the T wave in the heart's electrical cycle. ... A lengthened QT interval is a marker for the potential of ventricular tachyarrhythmias like torsades de pointes and a risk factor for sudden death.read more >>