[Determination of the pulse wave spreading rate by the 1st rheographic derivative]

Besides via sphygmography, the propagation rate of pulse wave (PRPW) could be determined also by a synchronous record of volume and differential rheograms of aorta and limbs. For that purpose, 110 clinically healthy subjects were examined, grouped in 3 age groups (15-40, 41-60 and over 60). Synchronous rheographic records from the initial and terminal part of descending aorta with determination of PRRPW along vessels of elastic type (Ve) and from the arch of the aorta-left forearm--for vessels of muscular type (Vm) were recorded. By variation analysis the average values of Vm, Ve and the ratio Vm/Ve for the separate age groups within a norm were derived. With the analysis of the values obtained, an increase of PRRPW with age advancing along both traces (Vm, Ve) in the first two groups was established. PRRPW increase was more significant in the elderly group (over 60); mainly on account of the vessels of elastic type (Ve). The ratio Vm/Ve, which in normal subjects is always over unity, in youths and at a moderate age tends to approach unity or to drop under unity with advanced age. In 15 of the patients, with hypertonic disease, second stage, both PRRPW along VE and the diminution of the ratio Vm/Ve to or under unity is more pronounced in patients with hypertonic disease, stage II, B. In 15 patients with advanced age, with clinically confirmed atherosclerosis, but without hypertension, PRRPW was the largest, the ratio Vm/Ve being always under unity. After a technical reconstruction the 3-canal ECG apparatuses type NEK-3 could adequately be used both for synchronous rheographic records and determinations of PRRPW along the vessels of elastic and muscular type.