1982 Volume 19 Issue 6 Pages 610-616
The validity of ISP test in the diagnosis of ischemic heart disease in the aged was evaluated in 150 autopsied cases, ranging in age at the time of death from 60 to 90 years old (79.0±8.0, mean±SD).
ISP was infused at a rate of 0.02μg/kg/min for five minutes. The electrocardiogram was recorded before, during & until 5 minutes after ISP infusion. Bipolar lead of C5-C5R and standard 12 lead ECG were used.
The additional ST segment depression of 0.5mm or greater of the iscchemic type was considered to be the positive test. The sensitivity in 60 severe coronary stenosis of 75% or more was 73.3% and specificity in 90 mild coronary stenosis was 81.1% After excluding 24 cases of myocardial infarction sensitivity was elevated to 80.0%. The severity of ST depression after ISP test was correlated with the number of the stenotic branches. Decrease in negative amplitude of initially negative T was more frequently observed in severe coronary stenosis than in mild coronary stenosis, but the difference was not statistically significant. R wave amplitude changes in C5-C5R were measured after ISP infusion. Increase or no change of R wave was slightly more frequent in severe coronary stenosis but not of diagnostic value. In myocardial infarction the severe stenosis of the coronary artery supplying non-infarction areas was found in 10 out of 13 ISP positive cases, while it was found in 2 out of 11 ISP negative cases. In other words, positive ISP test in prior myocardial infarction suggests multivessel disease. The reinfarction was more frequently observed in ISP positive cases than in negative cases
In summary, ISP test, especially ST change after infusion, was useful in the assessment of coronary stenosis including myocardial infarction.
