Intravascular and extravascular pulmonary fluid volumes during chronic experimental left ventricular dysfunction

To assess the effects of chronic left ventricular (LV) dysfunction on intravascular pulmonary blood volume (PBV) and extravascular lung water (EVLW) lung fluid volumes, 56 dogs were evaluated by means of double-indicator dilution techniques. PBV and EVLW were measured in seven control dogs, in eight dogs 4 hours after the production of left heart dysfunction, and then in three additional groups of dogs (n = seven in each group) 7, 14, and 30 days after the production of LV dysfunction. Twenty dogs were excluded because we were unable to produce elevations in LV end-diastolic volume greater than 25 mm Hg. EVLW was measured using heat as the diffusible indicator, and electric shock was used to create heart block and myocardial scarring in order to produce LV dysfunction. Plasma volume was calculated prior to death by means of radioiodinated albumin. In the remaining animals, electric shock acutely and chronically elevated LV end-diastolic pressure (control 2.3 +/- 1.0 mm Hg; postshock pressures greater than 25 mm Hg). PBV increased initially after cardiac failure and remained so as time progressed, although it represented a smaller fraction of the plasma volume as time passed (11.2 +/- 2.1% control, 15.9 +/- 3.4% at 4 hours after failure, and 12.6 +/- 2.0% at 7 days; the former p less than 0.005 vs control, the latter p less than 0.01 vs control). EVLW increased as time progressed, in consort with small but progressive increases in left atrial pressure. Thus, we conclude that the effects of acute and chronic LV dysfunction on pulmonary circulation are significantly different.(ABSTRACT TRUNCATED AT 250 WORDS)