Used primarily in the diagnosis of Brugada syndrome, ajmaline is administered intravenously during electrophysiological testing to unmask characteristic ECG patterns. It helps identify individuals at risk for sudden cardiac arrhythmias by provoking ST-segment elevation in leads V1–V3 when the condition is present. Due to its potent antiarrhythmic properties, it is also used in some countries to treat certain types of cardiac arrhythmias, particularly those involving the ventricles. Its use requires strict medical supervision because of the risk of proarrhythmia.