A Method for Measuring Venous Tone in Digital Veins of Intact Man

Abstract

It HAS been suggested that the tone of the veins is increased in chronic congestive heart failure,* but, because the evidence has been indirect and unconvincing, the concept has not been fully accepted.\s=d\ Some of the data reported \ s=dd\ may be interpreted to support an increase in venous tone. Because the neck veins are distended in patients suffering with congestive heart failure, the blood volume is considered by many to be increased and venous tone to be decreased. That this is not necessarily true has been indicated by previous studies,\s=s\ as well as by the observation that blood volume may be only slightly to moderately increased, if at all, in congestive heart failure.\m=par\ Thus, it is desirable to study venous tone in congestive heart failure further.A venous occlusive pneumoplethysmographic method has recently been developed in this laboratory that permits simultaneous measurements of the continuous curves of the time courses of the volume, rate, and acceleration in rate of inflow, outflow, and difference between inflow and outflow for the intact finger tip of man.jj This method lends itself to a study of aspects of the behavior of the veins in the intact digit of normal man as well as subjects with chronic congestive heart failure. Data presented in this report are compatible with an increase in tone in the venous, as well as arterial, side of the digital vascular bed in subjects with severe chronic right and left ventricular congestive heart failure.Venous tone is defined as the tendency of the vein to resist distention. This resist¬ ance is due in part to a state of contraction or tension offered by the smooth muscle in the wall of the vein. Whenever there is a tendency for the vein to be distended,

The Contribution of Local Factors to the Elevated Venous Tone of Congestive Heart Failure

“…These studies reconfirm the presence of an increased venous tone in heart failure (1)(2)(3)(4)(5)(6)17) Fig. 3A.…”

“…Previously it has been suggested that patients with congestive heart failure have an increased venous tone (1)(2)(3)(4)(5)(6). This has been thought to be secondary to an exaggerated sympathoadrenal discharge (6).…”

“…CHF patients had a significantly lower VV-[30] at rest and after intra-arterial phentolamine (2 mg) than normal subjects, suggesting that in these patients a state of peripheral venoconstriction existed (rest-N: 4.63+0.17, CHF: 1.7±0.23 ml/100 ml, P < 0.01; pre-and postphentolamine-N: 4.85±0.21 to 4.95 ±0.31, CHF: 2.26±0.29 to 2.68±0.38 ml/100 ml, P <0.01). Of note is that alpha adrenergic blockade failed to increase VV [30] significantly in N, but did increase it in CHF (P < 0.05), suggesting that part of the decreased VV [30] in CHF in due to an augmented sympathoadrenal discharge.…”

Studies on Starling's Law of the Heart. I. The Circulatory Response to Acute Hypervolemia and Its Modification by Ganglionic Blockade

“…In particular, ganglionic blockade produces venodilatation in patients in congestive heart failure (35,36) and in normal subjects during muscular exercise (34). The experiments of Freis and associates have also suggested that hexamethonium blocks reflex venoconstriction in normal subjects (37).…”

The Hemodynamic Effects of Hexamethonium Bromide in the Dog, With Special Reference to “Splanchnic Pooling” 1

“…This response may be attributed 1) to a slight but widespread change in venous tone that results in a generalized retardation in venous flow, 2) to local "pooling" of blood in venous reservoirs or 3) to both. The increased distensibility of the digital veins in human subjects following intravenous administration of hexamethonium (6) gives some support to the first possibility, but the digital vasculature is highly specialized and may not faithfully reflect changes elsewhere. Moreover, a larger quantity of blood is held in other parts of the venous system where even limited changes in tone might be expected to have a correspondingly greater effect upon venous pressure and return.…”