tricrotism

from The Century Dictionary.

• noun The state of being tricrotic: used of the pulse. See cut under sphygmogram.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Physiol.) That condition of the arterial pulse in which there is a triple beat. The pulse curve obtained in the sphygmographic tracing characteristic of tricrotism shows two secondary crests in addition to the primary.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun biology The condition of the arterial pulse in which there is a triple beat, so that the pulse curve obtained in a sphygmographic tracing shows two secondary crests in addition to the primary one.