Exercise-induced stunning continues for at least one hour: evaluation with quantitative gated single-photon emission tomography.
To elucidate the after-effect of exercise on left ventricular (LV) function, end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (LVEF) were evaluated at 1 h after exercise and at rest by technetium-99m tetrofosmin gated myocardial single-photon emission tomography (SPET) using an automated program in 53 subjects. The subjects were grouped as follows: normal scan (n = 16), ischaemia (n = 19) and infarction (n = 18), based on the interpretation of perfusion images. Postexercise LVEF did not differ from resting LVEF in the groups with normal scan and infarction. In patients with ischaemia, postexercise EDV (90+/-17 ml, mean +/-SD) and ESV (44+/-15 ml) were significantly higher than EDV (84+/-15 ml, P = 0.001) and ESV (36+/-14 ml, P<0.0005) at rest. LVEF was significantly depressed 1 h after exercise (53%+/-9% vs 58%+/-9%, P<0.0001). In ischaemic patients with depressed postexercise LVEF, LVEF difference between rest and postexercise showed a significant correlation with the sum of defect scores, which were reversible from exercise to rest perfusion images (r = 0.92, P<0.0001). These results indicate that exercise-induced LV dysfunction (myocardial stunning) continues for at least 1 h in ischaemic patients and that the extent of LVEF depression is determined by the severity of ischaemia.
Paul
A K
AK
Division of Tracer Kinetics, Biomedical Research Center, Osaka University Medical School, Suita, Osaka, Japan.
Hasegawa
S
S
Yoshioka
J
J
Tsujimura
E
E
Yamaguchi
H
H
Tokita
N
N
Maruyama
A
A
Xiuli
M
M
Nishimura
T
T
D001810:Blood Volume / Q000502:physiology; D003327:Coronary Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D015444:Exercise / Q000502:physiology*; D005260:Female; D015637:Gated Blood-Pool Imaging; D006321:Heart / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D012146:Rest / Q000502:physiology; D013318:Stroke Volume / Q000502:physiology; D015899:Tomography, Emission-Computed, Single-Photon; D016277:Ventricular Function, Left / Q000502:physiology
D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C078700:technetium tc-99m tetrofosmin