As a medical professional with expertise in cardiology, I can provide you with information on the normal QT interval. 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, as measured on an electrocardiogram (ECG). It represents the time for both depolarization and repolarization of the ventricles to occur. The normal QT interval can vary based on several factors, including age, gender, and heart rate. In adults, a normal QT interval is typically between 0.36 to 0.44 seconds at a heart rate of 60 beats per minute (bpm). It's important to note that the QT interval can be corrected (QTc) for heart rates other than 60 bpm using various formulas, such as the Bazett's formula, to account for the effect of heart rate on the QT interval. Here is the information in English, followed by the translation in Chinese, separated by "read more >>

For risk of sudden cardiac death, "borderline QTc" in males is 431�C450 ms; and, in females, 451�C470 ms. An "abnormal" QTc in males is a QTc above 450 ms; and, in females, above 470 ms. ... For example, taking normal QTc �� 0.42 s, QT would be expected to be 0.42 s or less at a heart rate of 60 bpm.read more >>