Ramon L. Lange

Brisket disease: II. Clinical features and hemodynamic observations in altitude-dependent right heart failure of cattle

Abstract In cattle grazing during the summer months at altitudes between 8,000 and 12,000 feet (2,500 to 3,700 meters) in Utah and Colorado severe congestive heart failure develops. The disease is apparently the consequence of severe pulmonary hypertension which develops in this species in response to moderate altitudes. This form of chronic mountain sickness has many similarities to pulmonary hypertensive heart disease in man. It differs from Monges disease in certain significant aspects. It is assumed that the peculiar structure of the pulmonary vascular bed in this species causes an excessive vasoconstrictive response at a reduction in partial pressure of oxygen which is still easily tolerated by man.

Some Evidence for Active Constriction in the Human Pulmonary Vascular Bed

Continuous infusion of norepinephrine in man caused a rise in pulmonary arteriolar resistance as measured by pulmonary artery-pulmonary wedge pressure differences. Since no change in flow occurred during the procedures, the data suggest active constriction of the pulmonary vascular bed under these circumstances.

Postvalvular Stenosis of the Pulmonary Artery

Constrictive lesions of the pulmonary artery or its branches occur distal to the pulmonic valve. Four patients whose surgical or cardiac catheterization findings demonstrated such postvalvular stenosis are reported. The significance of such findings is discussed and diagnostic misinterpretations are mentioned.

BRISKET DISEASE. III. SPONTANEOUS REMISSION OF PULMONARY HYPERTENSION AND RECOVERY FROM HEART FAILURE.

Previous reports from this laboratory have dealt with the ecologic, pathologic, clinical, and pathophysiologic features of brisket disease (1, 2). On the basis of these studies brisket disease may be defined as altitude-dependent, pulmonary, hypertensive heart disease in cattle of the species Bos taiurus. Briefly, the disease in Utah occurs primarily in young calves usually during their first exposure to conditions existing on summer ranges at elevations between 8,000 and 11,000 feet. Typical findings in animals suffering from brisket disease are outlined in Table 1. It was observed that a significant number of animals with acute brisket disease recovered when removed from the mountainous ranges and brought to Salt Lake City, Utah (elevation 4,500 feet). This observation prompted an investigation of the nature, magnitude, and time course of changes in various physiologic parameters associated with clinical recovery. The demonstration of dramatic remission from pulmonary hypertension and improvement in over-all cardiovascular function provides the basis for this report.

Quantitation of Valvular Regurgitation from Multiple Indicator-Dilution Curves

Dye-dilution curves obtained simultaneously from the pulmonary artery and from the femoral artery following an intravenous injection of T 1824 or Indocyanine Green in normal subjects and in patients with nonregurgitant heart disease yielded a similar contour. This suggested that in the absence of regurgitation the parameters of the distal (arterial) curve can be predicted from the proximal (pulmonary artery) curve. The distortion of the arterial curve by regurgitation can therefore be compared with the undistorted pulmonary artery curve. To the extent that 2 identifiable and measurable flow rates exist between the sites of sampling, a theoretical basis for quantitation of the degree of valvular regurgitation may be derived.

Variant Hemodynamic Patterns in Mitral Stenosis

Of a total group of 86, 11 cases of proved significant mitral stenosis with cardiovascular hemodynamic data are presented. Four had normal pulmonary wedge and pulmonary artery pressures at rest and low cardiac index at rest and after mild exercise. It is postulated that such persons respond to mitral valve obstruction primarily by lowering cardiac output. The cardiac index in seven was normal at rest and after mild exercise. Thus there was no evidence that alteration of blood flow had occurred in response to the lesion. The values for pulmonary arteriolar resistance in three of these were qualitatively normal when flow was increased. These are considered to be examples of absent or inadequate changes in pulmonary vascular reactivity. The existence in a significant percentage of patients with mitral stenosis of a low cardiac output with normal resting pulmonary, arteriolar, and wedge pressures, or normal cardiac output despite elevation of these pressures infers that potent flow-regulating factors tors can operate independently of the obstructive lesion.

Postural hypotension with decreased central blood volume and impaired aldosterone response

Abstract A case of postural hypotension due to urinary salt wasting is presented. Subnormal aldosterone excretion rates in response to salt depletion, hypotension and angiotensin infusion was demonstrated, with apparently normal renal, adrenal and pituitary function. The hemodynamic patterns of hypovolemia, particularly a reduction in central blood volume and consequent hypotension associated with tilting, was observed. Therapy with supplemental sodium chloride relieved the patients symptoms but became unnecessary when her weight returned to the presymptomatic level.

The concept of functional coarctation of large blood vessels

Abstract 1. 1. Passing two arterial catheters into the central portion of the arterial circulation, above and below a suspected area of constriction, allows a simple and precise localization of coarctation. 2. 2. Analysis of pressure differences across the defect includes changes in systolic and in mean pressures, and in measurements of the slope of the curves. The latter is considered a particularly sensitive index of functionally significant obstruction. 3. 3. These physiologic parameters may be normal in the face of an anatomically demonstrable narrowing of the aortic channel. Under these circumstances surgical repair seems unnecessary. 4. 4. The pressure changes of coarctation can be simulated by appropriate hydraulic and electric analogues which emphasize that alterations in flow through the narrowed channel alone may be sufficient to reproduce many of the clinical findings.