The normal QTc is 0.39 for males and 0.41 for females. Minor elevations above these numbers (ie 0.43 seconds) is not likely to cause problems. Generally, physicians consider 0.47 for men and 0.48 the minimum number needed to diagnose Long QT Syndrome (in the absence of correctable causes). The greater the elevation above these values, the greater the risk for arrhythmia and sudden death.
For educational purposes only. Not for clinical use! Answers are rounded to the nearest hundredth