Significance of ST depression during exercise treadmill stress and adenosine infusion myocardial perfusion imaging.
BACKGROUND
ST segment depression on the electrocardiogram during the exercise treadmill test (ETT) is used as a predictor of coronary artery disease (CAD), although it is recognised that both false-positive and false-negative results limit the value of this procedure. Although adenosine does not produce an inotropic or chronotropic effect upon the myocardium it may cause ST depression during infusion.


METHODS
The 12-lead ECG recordings obtained during 825 adenosine stress and 425 ETT procedures, performed as part of a 2-day Tc-MIBI protocol, were retained for examination and comparison with the appearances at subsequent myocardial perfusion imaging (MPI).


RESULTS
ST depression was associated with 44 (4.9%) of the adenosine stress and 44 (10.4%) of the ETT procedures. Both 1 and 2 mm ST depression during adenosine stress were significant predictors of reversible ischaemia (p < 0.01; p < 0.01). However, even though 2 mm ST depression on ETT was significant as a predictor of reversible ischaemia (p < 0.01), 1 mm ST depression on ETT was not (p = 0.4). There were more female cases with false positive ECG changes in both the adenosine stress (63.6%) group and the ETT (66.7%) group. There was no significant correlation between the territory of the ischaemic changes seen on the ECG with the location of defects developing on MPI in both the adenosine stress and ETT groups.


CONCLUSIONS
ST depression of 1 mm occurring with adenosine stress, unlike with the ETT, is a significant predictor of ischaemia.
Yap
Lok B
LB
Division of Cardiology, Homerton Hospital, Homerton Row, London E9 6SR, UK. lokyap@lycos.com
Arshad
Waleed
W
Jain
Ajay
A
Kurbaan
Arvinder S
AS
Garvie
Neil W
NW
D000241:Adenosine; D016022:Case-Control Studies; D003326:Coronary Circulation; D004562:Electrocardiography; D005080:Exercise Test; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011237:Predictive Value of Tests; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D012737:Sex Factors; D017256:Technetium Tc 99m Sestamibi; D014665:Vasodilator Agents
D019275:Radiopharmaceuticals; D014665:Vasodilator Agents; D017256:Technetium Tc 99m Sestamibi; D000241:Adenosine