Evidence for Pulmonary Venoconstriction in Brisket Disease

Measurements were made of simultaneous pulmonary artery wedge (PAw ) and left ventricular diastolic (LVed ) pressures 39 times during 21 venous and left ventricular cardiac catheterization studies in eight animals with brisket disease. Each animal was studied during the acute phase of the disease. The remaining 13 studies were carried out in six animals at various intervals during spontaneous recovery from pulmonary hypertension and heart failure. A pressure gradient between PAw and LVed (δP) which averaged 14.6 ± 1.6 (SE) mm Hg was demonstrated in 12 measurements during seven studies in four animals (group A). The δP in 27 measurements during 14 studies in six animals averaged 2.4 ±0.8 mm Hg (group B). Venous resistance (Rv ) represented 39±5% of the total resistance (RT ) of pulmonary vessels in group A and 13±4% in group B studies. The δP and Rv /RT in group A animals are consistent with findings caused by pulmonary venous obstruction. The obstruction was interpreted to represent the effect of pulmonary venoconstriction.