Long QT syndrome

This code represents a primary electrical disorder of the heart characterized by a prolonged QT interval on an electrocardiogram (ECG), predisposing individuals to life-threatening ventricular arrhythmias, such as Torsades de Pointes. It is an inherited channelopathy affecting cardiac repolarization, leading to an increased risk of sudden cardiac death.

Use this code for patients diagnosed with congenital or acquired long QT syndrome, confirmed by ECG findings of a prolonged QT interval and clinical symptoms such as syncope, seizures, or sudden cardiac arrest. Documentation should clearly state the diagnosis of long QT syndrome, often supported by genetic testing results or a family history of the condition.

• Differentiate from other cardiac arrhythmias; this code is specific to long QT syndrome, not just any prolonged QT interval.
• Ensure documentation specifies "long QT syndrome" rather than just "prolonged QT" to support this specific diagnosis.
• Consider sequencing with codes for associated symptoms (e.g., syncope R55) or complications (e.g., cardiac arrest I46.2) as appropriate.