I manage my Ventricular Tachycardias with Flecainide. It has harsh side effects but it does suppress VTs. I'm sure your drugs would be milder. Before committing to a new drug, I would start supplementing 400 mg of magnesium every day just to make sure it isn't as simple as low magnesium. Blood tests can show you are in range, but it doesn't say anything about magnesium in the heart, which is critical for cardiac conduction.