Key result
RP-index strongly inversely correlates with local blood pressure changes during lower extremity positional shifts.
Why the study?
The relation of pulse wave transmission time (RP-index) to blood flow and blood pressure in the lower leg and the effects of warming and cooling on these parameters were not well understood.
How do positional changes and temperature variations (warming/cooling) affect pulse wave transmission time (RP-index), blood flow, and local blood pressure in the lower extremity?
Observational (n=9)
No
How do positional changes and temperature variations (warming/cooling) affect pulse wave transmission time (RP-index), blood flow, and local blood pressure in the lower extremity?
Pulse wave transmission time (RP-index) correlates negatively with local blood pressure changes and is modulated by temperature-induced changes in peripheral circulation.
RP-index may aid noninvasive lower extremity hemodynamic evaluation; hypothesis-generating and requires validation before clinical adoption.
Using a photoelectric apparatus, pulse waves were obtained from the great toe of the left foot, and were recorded simultaneously with electrocardiogram. The time interval between the peak of the R wave in EKG and that of the pulse wave was divided by the distance between the tip of the xyphoid process and the medial malleolus of the left leg to obtain the transmission time of the pulse wave (RP-index). The relation of the RP-index to the blood flow and blood pressure of lower leg as well as the effect of warming and cooling of lower upon these parameters were studied. The results obtained were as follows: 11. During rest, there was no linear correlation between the RP-index and blood flowof the lower extremity.2. There was an negative correlation (r=-0.67, p<0.01) between the RP-index and the change in local blood pressure due to the positional change of the lower extremity.3. When the foot was warmed, the RP-index and blood flow increased and the local blood pressure decreased.4. When the foot was cooled, the RP-index and blood flow decreased and the local pressure increased.5. When cooling and warming is of an excessive degree, the change of the peripheral circulatory regulation by the autonomic nervous reflex is influenced by the magnitude of the RP-index.
No takes yet. Share an insight, caveat, or question.
Kawakami et al. (1968) conducted an observational in Healthy (n=9). Positional change, warming, and cooling of the lower extremity vs. Resting baseline was evaluated on Correlation between the RP-index (pulse wave transmission time) and local blood pressure changes due to positional change (r=-0.67, p=<0.01). There was a significant negative correlation (r=-0.67, p<0.01) between the RP-index and the change in local blood pressure due to positional changes of the lower extremity.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: