Hello, I am a 42 year old male. 6 tall, 220 pounds. I have been having heart palpitations for the last 6 years. This all started after I had an anxiety attack. About 3 years ago, I awoke out of sleep early in the morning, and my heart was in A-Fib. I have wore halter monitors, have had EKG s, echos of my heart. These palpitations I get are very hard. They can sometimes briefly even take my breath away and/or make me feel faint. I can have the heart palps for a few days, then they disappear for weeks and/or months, then out of the blue, they come back. I currently take 25 mgs Metoprolol twice a day, flecainide 100mgs twice a day, and venlafaxine XR 150mgs twice a day. I have looked at diet, quit smoking, tried calming exercises ect......Now my regular health care doctor thinks the medicines are no longer working like they should, and he scheduled me into a heart doctor. What will they be looking for?