The effect of pituitary substance upon the pulse form of febrile patients

In a recent study of dicrotic and monocrotic pulse forms it was shown that these are always accompanied by a transient backward movement of the blood column in the brachial artery just after the entrance of the primary pulse wave. This backward movement may be due either to local conditions in the arm which permit an unusual reflection of the pulse wave or to conditions elsewhere in the cardiovascular apparatus which permit the reflected wave, itself perhaps normal, to become evident on our tracings. Further observations indicate that this type of pulse is common in fever patients and that it is rarely marked in normal individuals. It is the type of pulse that has frequently been described as bounding, poorly sustained, pointed, etc.—terms which refer to the sudden fall of pressure immediately after the primary pulse wave.

This type of pulse as it occurs in febrile patients may be converted into a normal form by therapeutic doses of a pituitary preparation. 1 Following such an injection the pulse form usually showed a definite change in from ten to fifteen minutes, the maximum effect was reached in about an hour, and the effect did not pass off for two or three hours. The degree of change varied in different patients. Frequently it was so marked that not a trace of the original backflow remained and the pointed character of the volume pulse from the arm was entirely lost. Thus far we have not been able to determine any fixed relation between the change in pulse form and changes in the systolic blood pressure or changes in the rate of blood flow throughout the arm. The change in form however was regularly accompanied by a diminution in the size of the volume pulse in the arm.