@loswalt0525 Both tartrate and succiante are the same drug. The difference is the coating. Tartrate is released quickly and succinate is released slowly hence time released. Both will lower your ventricular rate by targeting beta andregenic nerves (sympathetics). Metropolol is specific to the AV node so even though your ventricular rate slows down (that's the pulse you feel in your wrist for example) but you're still in fib bc metropolol does nothing to the atria and that's the fibrillation / quivering clot producing basics in Afib or flutters.

Best to talk with your Dr. for specific advice dosages alternative drugs etc.