Alterations in myocardial metabolism and function at rest in stable angina pectoris: relations with the amount of exercise-induced thallium-201 perfusion defect.
The relation between the amount of exercise-induced ischemia and alterations in left ventricular (LV) function and metabolism at rest was studied in 18 coronary patients with stable angina pectoris. An ischemic defect area score was computed from quantitative exercise thallium-201 (Tl-201) scintigraphy; this estimation of the amount of ischemic myocardium was used to classify the patients in group I (n = 8; score less than 15%, mean 6.7 +/- 2.5%) and II (n = 10; score greater than 15%; mean 27.2 +/- 8.9%). Hemodynamics and metabolism were studied in basal state. No patient had anginal pain during the study, and the extent of angiographic coronary artery disease (CAD) was comparable in the two groups. Heart rate, aortic pressure, coronary blood flow, and myocardial oxygen uptake were also similar in both groups. However, ejection fraction was reduced in group II (51 +/- 13 vs 63 +/- 5%; p less than 0.01) and LV relaxation was impaired as shown by the increase in time-constant of isovolumic pressure fall (55 +/- 16 vs 44 +/- 6 ms in group I; p less than 0.05); the LV end-diastolic pressure was also increased in group II (19 +/- 8 vs 10 +/- 4 mmHg in group l; p less than 0.05). Furthermore, in group II, myocardial lactate uptake was reduced (4 +/- 19 vs 30 +/- 29 mumole/min in group I; p less than 0.01) and the productions of alanine and glutamine were augmented (-7.5 +/- 4.4 vs -4.6 +/- 1.6 mumole/min in group I; p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
D000328:Adult; D000368:Aged; D000787:Angina Pectoris / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000503:physiopathology; D006328:Cardiac Catheterization; D017023:Coronary Angiography; D004562:Electrocardiography; D006321:Heart / Q000503:physiopathology*; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism*; D010477:Perfusion; D005082:Physical Exertion; D011868:Radioisotopes; D011877:Radionuclide Imaging; D013793:Thallium
D011868:Radioisotopes; D013793:Thallium