In the morning under NOT , the heart rate-adjusted QT ( QTc ) interval was decreased compared with placebo ( mean difference , -@ milliseconds ; @ % CI , -@ to -@ milliseconds ; P = @ ) , and the interval between the peak and the end of the T wave on the ECG was shorter compared with acetazolamide ( mean difference , -@ milliseconds ; @ % CI , -@ to -@ milliseconds ; P = @ ) .