Some medications, particularly antiarrhythmic drugs that block the cardiac sodium current INa, can reveal a Type 1 Brugada pattern in susceptible people. These drugs can be used to help make a diagnosis in those suspected of having Brugada syndrome (e.g. survivors of an unexplained cardiac arrest, family members of a person with Brugada syndrome) but in whom a diagnostic ECG pattern has not been seen.[1] In these cases, sodium current blocking medications can be given in a controlled environment.[2] The most commonly used drugs for this purpose are ajmaline, flecainide, and procainamide, with some suggestions indicating that ajmaline may be the most effective.[3] Precaution must be taken in giving these medications as there is a small risk of causing abnormal heart rhythms.[21]