Postmortem imaging of antemortem myocardial ischaemia

Abstract

Objectives: To determine the minimum survival time for detection of antemortem myocardial ischaemia with postmortem imaging (PMI) techniques. Methods: Nine pigs underwent ligation of the left anterior descending (LAD) (8) and/or right coronary artery (RCA) branch (4), and were killed 30 min–6 h after ligation. PMI (MRI and CT angiography) was performed 2–55 h after euthanasia. Signal intensity of myocardial segments was measured. The hearts were removed, the coronary arteries injected to mark perfused segments, and sections submitted for histology. Results: MRI T2-weighted sequences showed the ischaemic area as hyperintense in 4/4 LAD ligations with ≥4 h of ischaemia but in 0/4 with <4 h. Histological evidence of ischaemia was present in 4/4 animals after 4 h. Right ventricular ischaemic myocardium was visible on MRI T2-weighted sequences after 6 h of ischaemia in one animal. CT angiography showed the occluded coronary artery in all cases. Conclusions: Ischaemic lesions of the left ventricle, but not of the right, at least 4 h old can be detected as hyperintense areas on T2-weighted postmortem MRI. This technique is most sensitive in the first 24 h after death. Other sequences did not enhance detection. Key Points: • Left ventricular myocardial ischaemia/infarction can be demonstrated by postmortem imaging (PMI). • Ischaemia/infarction is better detected if survival time is at least 4 h. • Right ventricular ischaemia/infarction is not reliably detected by PMI. • Computed tomography angiography can demonstrate arterial occlusion.