If your heart rhythm is regular don't worry!
I am Dr.Rovena.
I read vary carefully your query and understand your concern.
The normal range for heart beat is considered 60-80 beats/min.
Your heart rate of 70 beats/min isn't considered high even when you are taking Sotolol to decrease heart beat.
When you are taking b-blocker(such as Sotolol) your heart beat more slowly than normaly and the heart beat tend to be 50-60 beats/min.
That's why your doc. said that it was a good rhythm.
In my opinion having a heart beat of 70 beats/min is normal even when you take Sotolol as long as your heart beat rhythm is regular (we called it sinus rhythm
causes an irregular heart rate
.So If you are having atrial fibrilation if you feel your pulse it will be irregular and you will feel a ''fluttering''.
If you are feeling your heart racing or any of this other symptoms such as:
-Feeling of palpitations
-Shortness of breath
or exercise intolerance
probably you are having atrial fibrilation.
So If your pulse is regular and you aren't experiencing any of the above symptoms I don't think you need to go to hospital.
If your heart rate will increase and your pulse is irregular please seek medical attention.
I suggest to check your pulse regularly in order to identify abnormal heartbeat
Hope I was able to help you.If you have further questions please feel free to writ me.I will be happy to answer.