User:Kastellet/QRS/QTc

QRS / QTc is an ECG marker that shows potential to predict severe cardiac arrhythmias in various medical conditions.

The marker is a ratio between the QRS complex and the heart rate-corrected QT interval in the ECG. The QRS complex indicates how fast the heart is depolarized (activated), before it can contract, while the QT interval shows how long it takes before the heart repolarizes (the electrical activity normalizes) after depolarization. Both among hypothermic patients and patients who have overdosed on antidepressants, it seems that a low QRS / QTc ratio gives a higher risk of cardiac arrhythmias and cardiac arrest.