A theoretical approach to the volume pulse wave

Peripheral hemodynamics in patients with Fabry's disease

Altered vasomotor activity has been reported as a clinically prominent feature of Fabry's disease (angiokeratoma corporis diffusum universale). While symptomatic cardiovascular involvement occurs eventually in most patients with this disorder, little is known concerning the effect of Fabry's disease on peripheral hemodynamics. Peripheral hemodynamics in the extremities and digits were studied in eight patients with Fabry's disease by means of segmental and venous occlusion pneumoplethysmography and thermal probes, and the results obtained were compared with those of 10 normal subjects. Forearm vascular resistance in Fabry's disease patients was significantly higher (p less than 0.01) than that in normal subjects. Forearm venous capacitance in Fabry's disease was significantly lower (p less than 0.01). Segmental pulse volume amplitudes showed no significant difference in any segments (upper arm, wrist, thigh, above and below knee, and the calf) between the two groups. Finger and toe blood flow, finger and toe pulse volume, and temperature in the resting state were all significantly less (p less than 0.01, p less than 0.05: p less than 0.01, p less than 0.01: p less than 0.05, p less than 0.05, respectively) than those in normal subjects. Finger and toe blood flow and pulse volume after vasodilation procedures were significantly less (p less than 0.05, p less than 0.01: p less than 0.05, p less than 0.01, respectively) than those in normal subjects despite equal elevation of digital temperature obtained after vasodilation in both groups. These findings indicate the presence of vasoconstrictive process in both resistance vessels and capacitances vessels in cutaneous and skeletal muscular beds. A limited response in the cutaneous circulation to vasodilation procedures also was seen. These data suggest the possibility that latent enhanced sympathoadrenal discharge as well as the accumulation of glycolipid in the autonomic nervous system and vessel walls plays an important role in the disturbed pathophysiology of this disorder.

Diminished finger volume pulse in borderline hypertension: evidence for early structural vascular abnormality

Digital volume pulse maximum dilation was determined in 27 patients with borderline essential hypertension (BHT) and 28 age-matched normotensive controls (NT). Finger pulse volume (PV) and finger systolic pressure (SBP) were measured by pneumoplethysmography during vasodilation induced by combining direct and reflex heat dilation and reactive hyperemia. Finger SBP was higher (p less than 0.01) in BHT than in NT (120 +/- 18.7 vs. 104 +/- 14.8 mm Hg, respectively); PV was lower (p less than 0.01) in BHT than in NT (9.7 +/- 4.2 vs. 15.3 +/- 6 ml/5 ml finger X 10(-3). Pulse volume correlated inversely with SBP in BHT (r = -0.40, p less than 0.05) but was unrelated to SBP in NT. Pulse volume was not altered by high or low sodium intake in BHT or NT despite significant changes in plasma renin activity (PRA). In BHT finger vessels are less distensible at a higher pressure than in NT. This abnormality is demonstrable during maneuvers to withdraw sympathetic tone and is not influenced by alteration of PRA. These data support the concept that BHT can produce structural vascular change, and demonstrate that this abnormality can be detected by a relatively simple method.