Atenolol Sleep problems

I take 25mg at dinner and have experience interrupted sleep throughout the night. Is this a side effect? Sometimes i sleep 3 hours , and then another 1 hour, constantly waking up. Also seem to hear my heartbeat strongly at night with the medicine. I am 55, relatively good health but since taking it for mild hypertension (5 years) my sleep has changed, and has caused an anxiety problem. Any ideas? Or is this the way it is with this medicine.