Association of ST segment depression >5 min after exercise testing with severity of coronary artery disease

Objective: to determine the association of prolonged st segment depression after an exercise test with severity of coronary artery disease. methods: a cross sectional study of 100 consecutive patients referred to the cardiology laboratory for stress myocardial perfusion imaging (mpi) conducted between april-august 2008. all selected patients were monitored until their st segment depression was recovered to baseline. st segment recovery time was categorized into less and more than 5 minutes. subsequent gated spect-mpi was performed and stratified according to severity of perfusion defect. association was determined between post exercise st segment depression recovery time (<5 minutes and >5 minutes) and severity of perfusion defect on mpi. results: the mean age of the patients was 57.12 ± 9.0 years. the results showed statistically insignificant association (p>0.05) between st segment recovery time of <5 minutes and >5 minutes with low, intermediate or high risk mpi. conclusion: our findings suggest that the commonly used cut-off levels used in literature for prolonged, post exercise st segment depression (>5 minutes into recovery phase) does not correlate with severity of ischaemia based on mpi results.