May 1, 1950Open Access

Studies of the Pulmonary Circulation in Man at Rest. Normal Variations and the Interrelations Between Increased Pulmonary Blood Flow, Elevated Pulmonary Arterial Pressure, and High Pulmonary “Capillary” Pressures 1

LDL DexterBoston University JDJames DowBoston University FHFlorence W. HaynesUniversity College of the North

Structured PICO

How do increased pulmonary blood flow, elevated pulmonary arterial pressure, and high pulmonary capillary pressure affect pulmonary arteriolar resistance and pressure gradients in humans at rest?

Population

42 human subjects studied at rest, including 8 normal patients (some with treated syphilis), 9 with left-to-right shunts (7 atrial septal defect, 2 patent ductus arteriosus), 3 with Eisenmenger's complex, 11 with mitral stenosis, and 11 with left ventricular failure.

Intervention

Right heart catheterization to measure pulmonary artery pressure, pulmonary 'capillary' (wedge) pressure, cardiac output, and calculate pulmonary arteriolar resistance.

Comparator

Comparisons made between normal subjects and those with increased pulmonary blood flow (shunts), elevated pulmonary arterial pressure (Eisenmenger's), or high pulmonary capillary pressure (mitral stenosis/LV failure).

Outcome

Pulmonary hemodynamics including pulmonary artery pressure, pulmonary capillary pressure, pressure gradient, and pulmonary arteriolar resistance.surrogate

This foundational physiological study demonstrates that pulmonary arteriolar resistance increases significantly when pulmonary capillary pressure exceeds 20-25 mm Hg, acting as a protective mechanism against pulmonary edema.

Abstract

While many studies have been carried out on the dynamics of the pulmonary circulation in ex- perimental animals, few studies of this subject have been made in man until recently. With the advent of the cardiac catheter (

Ask AI

Helpful

Bookmark

View Full Paper