My primary care physician gave me Metropolol (50mg) to take only when I have SVT symptoms which is 1-2 times a month. It works maybe 15% of the time. My mother has afib and asked her cardiologist about this, who said you have to take Metropolol all the time for it to be effective, and not just when you have symptoms. Does anyone else have a prescription for Metropolol to take only during symptoms?