The frequency of asymptomatic and electrically silent exercise-induced regional myocardial ischemia during first-pass radionuclide angiography with upright bicycle ergometry.
The presence of asymptomatic (silent) myocardial ischemia during provocative testing may limit the detection of ischemic heart disease, unless sensitive indicators of ischemia are utilized. Exercise ventricular function studies are well suited for ischemia detection since segmental dysfunction is an early pathophysiologic event in the ischemic cascade. In this study, we examined the rest and stress first-pass radionuclide angiographic studies of 104 patients with coronary artery disease and exercise-induced regional wall motion abnormalities. Asymptomatic ischemia was observed in 83 patients, while only 21 patients were symptomatic. Clinical variables were not different between the two groups, except for a higher frequency of a prior anginal history in the symptomatic group. The peak heart rate and pressure-rate product were significantly higher in the silent ischemia group, as these patients are not limited by symptoms. Wall motion scores, resting and exercise ejection fractions were similar in the two groups. The frequency of an ischemic electrocardiographic ST-segment response was low, and was not significantly different between groups. These data indicate that electrically and symptomatically silent myocardial ischemia are frequent occurrences with upright bicycle ergometry. Without adjunctive cardiac imaging, this mode of exercise may not be appropriate for the evaluation of ischemic heart disease.
Williams
K A
KA
Department of Medicine (Cardiology), University of Chicago, Illinois.
Sherwood
D F
DF
Fisher
K M
KM
D000368:Aged; D003327:Coronary Disease / Q000000981:diagnostic imaging* / Q000209:etiology; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011875:Radionuclide Angiography; D012189:Retrospective Studies; D016284:Technetium Tc 99m Pentetate
D016284:Technetium Tc 99m Pentetate