Pattern of exercise-induced ST change is related to coronary flow reserve in patients with chest pain and normal coronary angiogram.
OBJECTIVE
To evaluate the usefulness of exercise treadmill test in determining the true microvasculature-induced ischemia, we compared the pattern of ST depression with coronary flow reserve (CFR) using transthoracic Doppler echocardiography (TTE) in patients with chest pain and normal coronary angiogram.


METHODS
Fifty-nine subjects (M/F=21:38, mean age 55+/-9 years) with chest pain and normal coronary angiogram underwent maximal symptom-limited exercise treadmill test (ETT). CFR was estimated with TTE and dipyridamole. Patients with a history of acute myocardial infarction, regional wall motion abnormalities, hypertrophic cardiomyopathy, ejection fraction less than 50%, or primary valvular heart disease were excluded from this study.


RESULTS
No ST change was observed in 20 of 59 (34%) patients, up slope depression was observed in 20 (34%), flat depression in 13 (22%), and down slope depression in 6 (10%). Eleven of thirty nine (28%) exercise positive patients had decreased CFR <2.1. CFR was 3.1+/-0.6 in group with no ST change, 3.1+/-0.6 in group with up slope depression, 2.1+/-0.6 in group with flat depression (p<0.05 versus group with no change and group with upslope depression, respectively), and 2.0+/-0.4 in group with down slope depression (p<0.05 versus group with no change and group with up slope depression, respectively). Flat to down slope depression of ST change during ETT had sensitivity of 58% and specificity of 95% for predicting CFR <2.1.


CONCLUSIONS
Flat and down slope depression of ST segment during ETT might increase the sensitivity and specificity to detect the true microvasculature-induced ischemia that is defined as CFR less than 2.1 in patients with chest pain and normal coronary angiogram.
Youn
Ho-Joong
HJ
Department of Internal Medicine, College of Medicine, The Catholic University of Korea, #62 Yoido-dong, Youngdungpo-ku, St. Mary's Hospital, Seoul, 150-713, South Korea. younhj@catholi.ac.kr
Park
Chul-Soo
CS
Cho
Eun-Joo
EJ
Jung
Hae-Ok
HO
Jeon
Hui-Kyung
HK
Lee
Jong-Min
JM
Oh
Yong-Seok
YS
Chung
Wook-Sung
WS
Kim
Jae-Hyung
JH
Choi
Kyu-Bo
KB
Hong
Soon-Jo
SJ
D000368:Aged; D001783:Blood Flow Velocity; D002302:Cardiac Output / Q000502:physiology*; D015150:Echocardiography, Doppler; D004562:Electrocardiography; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D017566:Microvascular Angina / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008875:Middle Aged; D012680:Sensitivity and Specificity