I have high blood pressure and take atenolol, I have my BP taken at the doctors regular basis. Yesterday my BP was taken and the upper of the measurements (systolic ?) was OK but the lower measurement (diastolic ?) was as the Doc said "way to low". She has increased my dosage of atenolol. I have googled BP & atenolol but can't seem to find the answer to this question "what is having a low second measurement called and does this mean that the blood being returned to the heart is slow ?" Thanks in advance for any help.