Contribution of systemic venous hypertension to the development of pulmonary edema in dogs.

Systemic venous hypertension (SVH) is a frequent finding in pulmonary edema. To study the possible contributory or even causal role of SVH in pulmonary edema, a dog model was developed in which balloon catheters were placed in the left and right atria. Inflation of the left atrial balloon produced a tendency to pulmonary edema by causing pulmonary venous hypertension (PVH) (pulmonary artery wedge pressure of 20 mmHg). Inflation of the right atrial balloon produced SVH (central venous pressure of 15 mm Hg). After 2 hours, dogs with SVH with or without PVH demonstrated a greater amount of lung fluid accumulation (P less than 0.01) compared to controls or PVH alone. There was no significant difference in lung water in SVH dogs with or without PVH. Pulmonary blood flow was not significantly different between the experimental groups, each of which was less than control. Impairment of pulmonary lymphatic flow is one possible mechanism producing the worsening edema; however, bronchial venous hypertension or neurogenic reflexes cannot be excluded. We conclude that the contribution of systemic venous hypertension to the development of pulmonary edema may have therapeutic implications.