CAN WE PREDICT THE SITE OF MYOCARDIAL ISCHEMIA BY EXERCISE INDUCED ST DEPRESSION?

Abstract

Objective: The aim of this study was to determine a relationship between exercise induced ST-depression and site of myocardial ischemia by SPECT Imaging. Methodology: This study was conducted at Atomic Energy Medical Center, Jinnah Postgraduate Medical Center, Karachi, Pakistan. A total of 82 consecutive patients who underwent exercise myocardial perfusion scan and developed significant ECG depressions were included in the study. Data was analyzed using SPSS version 10. All continuous variables were expressed as means ± SD. Chi square test was used to study the relationship between the site of ischemia on MPS and ST depression in different ECG groups. A p-value < 0.05 was considered statistically significant in analysis. Results: Out of 82 patients, 64 (78%) had abnormal scans; 62 patients revealed reversible perfusion defects and 18 patients' scans were declared normal. Patients had ST depressions in anterior leads were 25 but cardiac scans of only 4 patients (16%) showed anterior or antero-septal walls' perfusion defects, while 3 patients (12%) had lateral wall (infero-lateral / antero-lateral) defects and 4 patients showed inferior or infero-septal wall defects (16%). Conclusion: Our study revealed that ST depression on 12 lead Exercise ECG does not predict the site of myocardial ischemia by SPECT.