Study of viable myocardium in non-Q-wave myocardial infarction and Q-wave myocardial infarction with dual isotope SPECT myocardial imaging

Objective: To investigate ischemic viable myocardium in patients with non-Q-wave myocardial infarction (NQMI) and patients with Q-wave myocardial infarction (QMI) by gated SPECT with dual isotope, 99Tcm-methoxyisobutylisonitrile (MIBI) and 18F-fluorodeoxyglucose (FDG). Methods: Forty-five patients with previous myocardial infarction were included in this study and were divided into NQMI group (n=17) and QMI group (n=28). All patients underwent 99Tcm-MIBI gated myocardial perfusion imaging, 18F-FDG SPECT myocardial imaging and coronary angiography. Results: Ischemic viable myocardium was more common in NQMI group than in QMI group (100%:71%, P=0.017). The segments of ischemic viable myocardium were significantly more in NQMI group than in QMI group (P=0.001) and non-viable segments were significantly fewer in NQMI group than in QMI group (P=0.005). The value of left ventricular ejection fraction (LVEF) was significantly higher in NQMI group than in QMI group (P=0.000). There was good correlation between wall thickening and ischemic viable myocardium(r=0.671, P=0.000). The segments with abnormal wall thickening were significantly more in QMI group than in NQMI group (P=0.000). Conclusion: The study suggests that aggressive approaches should be taken to salvage the myocardium in NQMI patients. (authors)