diastolic pressure. The pressure pulse should therefore be greater.
When there is circulatory defect or abnormal blood pressure,
exercise may not increase the systolic pressure, and the pressure
pulse may grow smaller. As a working rule it should be noted that
the diastolic pressure is not as much influenced by physiologic
factors or the varying conditions of normal life as is the systolic
pressure.

In an irregularly acting heart the systolic pressure may vary
greatly, from 10 to 20 mm. or more, and a ventricular contraction
may not be of sufficient power to open the semilunar valves. Such
beats will show an intermittency in the blood pressure reading as
well as in the radial pulse. The succeeding heart beats after
abortive beats or after a contraction of less power have increased
force, and consequently give the highest blood pressure. Kilgore
urges that these highest pressures should not be taken as the true
systolic blood pressure, but the average of a series of these
varying blood pressures. In irregularly acting hearts it is best to
compress the arm at a point above which the systolic pressure is
heard, then gradually reduce the pressure until the first systolic
pressure is recorded, and then keep the pressure of the cuff at this
point and record the number of beats of the heart which are heard
during the minute. Then reduce the pressure 5 mm. and read again for
a minute, and so on down the scale until the varying systolic
pressures are recorded. The average of these pressures should be
read as the true systolic blood pressure. During an intermittency of
the pulse from a weak or intermittently acting ventricle, the
diastolic pressure will reach its lowest point, and in auricular
fibrillation the pressure pulse from the highest systolic to the
lowest diastolic may be very great.