Forearm venous distensibility in relation to severity of symptoms and hemodynamic data in patients with congestive...

The distensibility of the forearm veins in 24 patients with congestive heart failure was studied by occlusion plethysmography. Relationships between forearm venous distensibility and symptoms, hemodynamic data obtained by right heart catheterization and plasma levels of vasoactive hormones were evaluated. Forearm venous pressure (VP) and volume change (delta V) were measured simultaneously by the venous occlusion technique with strain gauge plethysmography. The relationship between venous pressure and volume change was fitted by the equation VP = c* exp (k* delta V) (r = 0.98 +/- 0.01) and the venous stiffness constant (k) was calculated. Venous volume change at a venous pressure of 20 mmHg (V20) was also measured as another index of venous compliance. The pressure-volume curve of the peripheral veins shifted leftward on the volume axis and the stiffness constant (k) increased as the New York Heart Association functional class grade increased. Mean pulmonary arterial pressure and pulmonary vascular resistance were closely related to k (r = 0.74, p less than 0.001; r = 0.73, p less than 0.001, respectively), and less closely to V20 (r = -0.56, p less than 0.004; r = -0.59, p less than 0.002, respectively). K and V20 were also related to stroke index (r = -0.57, p less than 0.004; r = 0.44, p less than 0.03, respectively) and stroke work index (r = -0.47, p less than 0.02; r = 0.45, p less than 0.03, respectively). K was also related to heart rate (r = 0.55, p less than 0.007), pulmonary capillary wedge pressure (r = 0.54, p less than 0.02), right atrial pressure (r = 0.51, p less than 0.02), cardiac index (r = -0.45, p less than 0.03), and systemic vascular resistance (r = 0.45, p less than 0.03). Both indexes were related to the plasma level of norepinephrine (r = 0.64, p less than 0.008; r = -0.52, p less than 0.04, respectively). We concluded that the venous tone was related to the severity of heart failure, especially to the symptoms, pulmonary arterial pressure and plasma concentration of norepinephrine, and that the venous stiffness constant, k, was a better parameter with which to assess peripheral venous tone.