I have WPW, or as I recently found out, Supraventricular Tachycardia. I was in the hospital for 3 days. I've had this for 40+ years and was on Quinidine and Metaprolol until I stopped taking it 7 months ago. I had a 12 hour episode and went to ER where they gave me a shot that stopped it immediately and was admitted for tests. My new cardiologist put me on Flecainide 50mg. twice a day. I've been taking it for 4 days and so far I've had one episode that lasted 3 hours and several little "blips" that lasted under 30 seconds. My question is this: should I give the drug time to work and get into my system, or should I be concerned if I have anymore short episodes? Is it suppose to stop the episodes as soon as I started taking it? Just wondering if I should call my doctor back or wait a few more days. Thanks in advance.