when systolic is high
If you have a diastolic number â the bottom number of a blood pressure measurement â less than 90 millimeters of mercury (mm Hg) and a systolic number â the top number of a blood pressure measurement â greater than 140 mm Hg, you have a common type of high blood pressure called isolated systolic hypertension.f you have a diastolic number â the bottom number of a blood pressure measurement â less than 90 millimeters of mercury (mm Hg) and a systolic number â the top number of a blood pressure measurement â greater than 140 mm Hg, you have a common type of high blood pressure called isolated systolic hypertension.