Assessment of left ventricular dysfunction by thallium-201 lung uptake during exercise in coronary artery disease.
To determine the clinical significance of an increased thallium-201 (Tl-201) activity in the lung and of its clearance from the lung after exercise, computer-quantitated Tl-201 lung activity was measured and compared with hemodynamic parameters at rest and during exercise in 35 patients with coronary artery disease (CAD). All patients underwent a supine bicycle ergometer exercise test and mean pulmonary artery wedge pressure (PAWP) was measured by a Swan-Ganz catheter. Coronary angiography was also performed. On computer-generated initial and 2 and a half hours delayed anterior images, regions of interest were selected over the myocardium (M) and lung (L), and the initial L/M ratio and the (initial L)/(delayed L) ratio were calculated as indices of an increased Tl-201 lung uptake and lung clearance, respectively. The initial L/M ratio and the (initial L)/(delayed L) ratio had no significant correlation with mean PAWP at rest and had a weak negative correlation with the resting ejection fraction (r = -0.57 and r = -0.58, respectively). However, both ratios showed good correlations with mean PAWP during peak exercise (r = 0.85 and r = 0.80, respectively), suggesting that they provide useful indices for assessing the severity of exercise-induced left ventricular dysfunction.
D000328:Adult; D000368:Aged; D003327:Coronary Disease / Q000503:physiopathology*; D005260:Female; D006321:Heart / Q000503:physiopathology*; D006352:Heart Ventricles / Q000503:physiopathology; D006439:Hemodynamics; D006801:Humans; D008168:Lung / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D005082:Physical Exertion; D011669:Pulmonary Wedge Pressure; D011868:Radioisotopes; D013793:Thallium
D011868:Radioisotopes; D013793:Thallium