Question: My cardiologist documented a prolonged QTc interval. What diagnosis code should I use?
Wisconsin Subscriber
Answer: You should use 426.82 (Long QT syndrome).
The QT interval is an indirect measure of the duration of the ventricular action potential (depolarization) and ventricular refractory period (repolarization). The length of the QT interval depends on the patient's heart rate. Therefore, the QT interval is usually corrected for the heart rate and denoted as "QTc."
Long QT syndrome affects the heart's electrical system and can result in a rapid heartbeat and fainting. If a patient with long QT syndrome presents complaining of dizziness, you should report this diagnosis with a code such as 780.4 (Dizziness and vertigo).