In arteriosclerosis the systolic may be high, and the diastolic low,
and hence a large pressure pulse. When the heart begins to fail in
this condition, the systolic pressure drops and the pressure pulse
shortens, and of course any improvement in this condition will be
shown by an increase in the systolic pressure. The same is true with
aortic regurgitation and a high systolic pressure.

If the systolic pressure is low and the diastolic very low, or when
the heart is rapid, circulation through the coronary vessels of the
heart is more or less imperfect. Any increase in arterial pressure
will therefore help the coronary circulation. The compression of a
tight bandage around the abdomen, or the infusion of blood or saline
solutions, especially when combined with minute amounts of
epinephrin, will raise the blood pressure and increase the coronary
circulation and therefore the nutrition of the heart.

MacKenzie [Footnote: MacKenzie: Med Rec., New York, Dec. 18, 1915.],
from a large number of insurance examinations in normal subjects,
finds that for each increase of 5 pulse beats the pressure rises 1
mm. He also finds that the effect of height on blood pressure in
adults seems to be negligible. On the other hand, it is now
generally proved that persons with overweight have a systolic
pressure greater than is normal for individuals of the same age. He
believes that diastolic pressure may range anywhere from 60 mm. of
mercury to 105, and the person still be normal. A figure much below
60 certainly shows dangerous loss of pressure, and one far below
this, except in profound heart weakness, is almost pathognomonic of
aortic regurgitation. While the systolic range from youth to over 60
years of age gradually increases, at the younger age anything below