Exercise-induced ST-segment elevation--role of left ventricular wall motion abnormalities and coronary artery narrowing.
We studied the causes of exercise-induced ST-segment elevation. Group I consisted of 15 patients with anterior myocardial infarction in the absence of a coronary artery luminal narrowing of 75% or more. Group II consisted of 36 patients with predominantly exertional angina and a luminal narrowing of 90% or more in the left anterior descending coronary artery in the absence of previous myocardial infarction. In group I, exercise-induced ST-segment elevation occurred frequently during treadmill exercise (15/15, 100%). None of the patients showed 201Tl redistribution. The standard deviation of the phase in radionuclide ventriculography increased during bicycle exercise. Of group II patients, only those with 99% narrowing and poor collaterals showed exercise-induced ST-segment elevation (13/14, 93%), whereas none of those with complete occlusion or 99% narrowing and good collaterals, or 90% narrowing showed ST-segment elevation. In group II, patients with exercise-induced ST-segment elevation showed lower 201Tl uptake during exercise and washout in the territory of the diseased vessel than those without exercise-induced ST-segment elevation. In conclusion, wall motion abnormalities may cause exercise-induced ST-segment elevation independently of myocardial ischemia. In patients with predominantly exertional angina, exercise-induced ST-segment elevation may be a marker for 99% narrowing with poor collaterals and severe myocardial ischemia.
Miyakoda
H
H
First Department of Internal Medicine, Tottori University School of Medicine, Yonago, Japan.
Kato
M
M
Noguchi
N
N
Omodani
H
H
Osaki
S
S
Matsumoto
T
T
Kinugawa
T
T
Hoshio
A
A
Kotake
H
H
Mashiba
H
H
D000328:Adult; D000368:Aged; D003097:Collateral Circulation; D003251:Constriction, Pathologic / Q000175:diagnosis / Q000503:physiopathology; D003326:Coronary Circulation; D003327:Coronary Disease / Q000175:diagnosis* / Q000503:physiopathology; D004562:Electrocardiography; D005080:Exercise Test; D005260:Female; D015637:Gated Blood-Pool Imaging; D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D009203:Myocardial Infarction / Q000175:diagnosis / Q000503:physiopathology; D012189:Retrospective Studies; D013794:Thallium Radioisotopes; D016277:Ventricular Function, Left
D013794:Thallium Radioisotopes