The diagnostic utility of heart rate-corrected ST-segment depression during adenosine nuclear stress testing.
BACKGROUND
Vasodilator stress testing relies heavily on the imaging portion so that clinically useful information from the electrocardiogram may be overlooked. Stress-induced ST-segment depression, although uncommon, is highly predictive of severe disease. We investigated whether minor ST depressions during adenosine nuclear stress testing corrected for the modest heart rate increases (ST/HR slope and ST/HR index) might be clinically relevant.


METHODS
The study included 74 consecutive patients with electrocardiograms interpretable for ischemia who underwent coronary angiography within the following 6 months.


RESULTS
Abnormal responses using conventional thresholds for ischemic ST depression, the ST/HR slope, and ST/HR index were present in 8%, 20%, and 27%, respectively. The sensitivity for conventional ST depression was 11% and, when corrected for heart rate, increased to 27% and 36%, (P = .012), without adversely affecting the high positive predictive accuracy (83%, 80%, and 80%). Even with a normal perfusion scan, heart rate correction was highly predictive of multivessel coronary artery disease (4/5 patients).


CONCLUSIONS
Heart rate correction of ST depression during adenosine nuclear stress improves on conventional ST depression and may compliment perfusion imaging in detecting multivessel disease.
Nemeth
Attila S
AS
Case Western Reserve University at MetroHealth Medical Center, 2500 MetroHealth Drive, Cleveland, OH 44109-1900, USA.
Bahler
Robert C
RC
Finkelhor
Robert S
RS
D000241:Adenosine / Q000008:administration & dosage; D016477:Artifacts; D003324:Coronary Artery Disease / Q000150:complications / Q000175:diagnosis*; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000150:complications / Q000175:diagnosis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D000241:Adenosine