These 10 animal facts will amaze you. Color blindness is most often a genetic visual deficiency that limits the colors that an individual can detect. Most people with this condition don't only see in black and white. The colors affected are usually limited to green and red, which often appear as shades of tan or brown.hese 10 animal facts will amaze you. Color blindness is most often a genetic visual deficiency that limits the colors that an individual can detect. Most people with this condition don't only see in black and white. The colors affected are usually limited to green and red, which often appear as shades of tan or brown.
The duration of the QT-interval varies dependent upon how fast the heart is beating, but in normal healthy people, when the heart is beating 60 beats per minute, it is between 350 and 440 milliseconds.
Schematic representation of normal ECG trace (sinus rhythm), with waves, segments, and intervals labeled. 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.pper limit of normal QT interval, corrected for heart rate according to Bazett's formula, Fridericia's formula and subtracting 0.02 s from QT for every 10 bpm increase in heart rate. Up to 0.42 s (â¤420 ms) is chosen as normal QTc of QT B and QT F in this diagram.