title: Left ventricular dysfunction during exercise in patients with angina pectoris and angiographically normal coronary arteries (syndrome X)
abstract: Left ventricular function during exercise and recovery was investigated in patients with angina pectoris, ST segment depression during exercise and angiographically normal coronary arteries (syndrome X) using a continuous left ventricular function monitor with cadmium telluride detector (CdTe-VEST). Fourteen patients with syndrome X and 14 patients with atypical chest pain without ST segment depression during exercise and normal coronary arteries (control group) performed supine ergometric exercise after administration of 740-925 MBq of technetium-99m labelled red blood cells, and left ventricular function was monitored every 20 s using CdTe-VEST. Left ventricular ejection fraction (EF) response was impaired (< or = 5% increase from rest to peak exercise) in 11 or 14 patients with syndrome X but in none of the control patients. Resting EF was similar in the two groups (62.1% +/- 6.7% in patients with syndrome X, 61.9% +/- 6.2% in controls); however, EF increase from rest to peak exercise was lower in syndrome X (-3.1 +/- 9.5% vs 14.7% +/- 7.4%, P < 0.001). After cessation of exercise, all patients showed rapid EF increase over baseline and this EF overshoot was lower (19.3% +/- 8.3% vs 26.4% +/- 7.3%, P < 0.001) with the time to EF overshoot longer (114 +/- 43 s vs 74 +/- 43 s, P < 0.05) in patients with syndrome X. Thus, in patients with syndrome X, left ventricular dysfunction was frequently observed during exercise in spite of normal epicardial coronary arteries.
authors.affiliation: Department of Nuclear Medicine, Kanazawa University School of Medicine, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Taki
authors.forename: K
authors.initials: K
authors.lastname: Nakajima
authors.forename: A
authors.initials: A
authors.lastname: Muramori
authors.forename: H
authors.initials: H
authors.lastname: Yoshio
authors.forename: M
authors.initials: M
authors.lastname: Shimizu
authors.forename: K
authors.initials: K
authors.lastname: Hisada
mesh_terms: D000328:Adult; D000368:Aged; D002637:Chest Pain / Q000209:etiology* / Q000503:physiopathology; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D017566:Microvascular Angina / Q000503:physiopathology*; D008875:Middle Aged; D016277:Ventricular Function, Left / Q000502:physiology*