The effect of systemic hypertension on exercise tomographic thallium-201 imaging in the absence of electrocardiographic left ventricular hypertrophy.
This study was designed to assess the effect of systemic hypertension on exercise thallium-201 imaging. The study group consisted of 38 patients with systemic hypertension who were compared with 68 normotensive patients. All patients had a low pretest likelihood of coronary artery disease to minimize the influence of selection bias. Patients with electrocardiographic evidence of left ventricular hypertrophy were excluded. Single-photon emission computed tomographic thallium-201 images were obtained immediately after exercise and 4 hours after exercise. Thallium tomographic images were assessed qualitatively by 14 short-axis segments and were grouped into three coronary distributions. Regional and global quantitative analysis was also performed by using a reference study group at low risk for coronary artery disease. The hypertensive group demonstrated higher resting systolic blood pressure (137 +/- 26 mm Hg vs 120 +/- 14 mm Hg in the normotensive group, p = 0.0002) immediately before exercise. There was no significant difference between hypertensive and normotensive groups in peak exercise systolic blood pressure (181 +/- 31 mm Hg vs 172 +/- mm Hg, p = NS). The normotensive group achieved a significantly higher peak exercise heart rate (162 +/- 18 vs 146 +/- 20 beats/min in the hypertensive group, p = 0.0001) and higher estimated oxygen uptake (11.0 +/- 3.4 vs 9.1 +/- 2.7 metabolic equivalents [METS] in the hypertensive group, p = 0.003). However, rate-pressure products for both groups were nearly identical.(ABSTRACT TRUNCATED AT 250 WORDS)
Grogan
M
M
Department of Cardiovascular Diseases and Internal Medicine, Mayo Clinic and Foundation, Rochester, MN 55905.
Christian
T F
TF
Miller
T D
TD
Bailey
K R
KR
Gibbons
R J
RJ
D000328:Adult; D003327:Coronary Disease / Q000000981:diagnostic imaging* / Q000453:epidemiology; D004562:Electrocardiography; D005080:Exercise Test; D005189:False Positive Reactions; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D017379:Hypertrophy, Left Ventricular / Q000175:diagnosis*; D007091:Image Processing, Computer-Assisted; D008297:Male; D011237:Predictive Value of Tests; D013794:Thallium Radioisotopes; D015899:Tomography, Emission-Computed, Single-Photon
D013794:Thallium Radioisotopes