[Evaluation of the cardiac performance in patients with coronary artery disease by the pulmonary blood volume change in exercise test].

Evaluation of the cardiac performance was studied by the change of the pulmonary blood volume (PBV) during the exercise testing in 17 normal subjects (group N), 18 patients with angina pectoris (group A) and 25 with both old myocardial infarction and angina pectoris (group M). The exercise testing was performed by bicycle ergometer in supine position. Blood pressure, heart rate, cardiac output measured by dye dilution method, left ventricular ejection fraction (EF) by multi-gate method, pulmonary artery pressure by Swan-Ganz catheter and PBV was measured during exercise. PBV was estimated by the radioactivity of the systemically administered Tc-99m labeled RBC in the lung field. ROI was adjusted over the right upper and lower lung field. And also the effect of the nitroglycerin was examined. In the result, (1) EF at the peak exercise increased in group N but decreased in group A and M, (2) Increased pulmonary artery diastolic pressure at the peak exercise (PAd at exercise) was remarkably higher in group A and M than group N. (3) PBV was unchanged in group N, however, increased 9.6% in group A and 10.9% in group M. (4) Increased rate of PBV revealed good correlation with delta EF (r = -0.68, p less than 0.01) and PAd at exercise (r = 0.83, p less than 0.01), and was considered as the pulmonary congestion due to left ventricular dysfunction. (5) After the sublingual administration of nitroglycerin, the increased PAd and PBV at the peak exercise was suppressed. Particularly, it was remarkable in group A. Then it was concluded that the noninvasive measurement of PBV during exercise could suggest the extent of the pulmonary congestion and was very useful for evaluation of the cardiac performance in coronary artery disease.