FUNCTIONAL AND ULTRASTRUCTURAL EVIDENCE OF MYOCARDIAL STUNNING AFTER ACUTE CARBON-MONOXIDE POISONING

Objective: To study human myocardial ultrastructural changes after car bon monoxide (CO) poisoning inducing reversible cardiac failure. Desig n: Case report: clinical, functional and morphologic findings. Setting s: Public university affiliated hospital and electron mi croscopy labo ratory. Patient: A 25-yr old woman with functional evidence of cardiac failure after acute CO poisoning. Interventions: Hyperbaric and inten sive care treatment over 10 days. Scintigraphic and cardiac angiograph y with endomyocardial biopsy. Measurements and Main Results: Scintigra phy with Tc-99m hexakis 2-methoxy-2-isobutyl isonitrile (sestaMIBI) sh owed an up take defect in the left anterior descending artery territor y, The cardiac angiography demonstrated a slight hypokinesis of the su perior two thirds of the anterior wall and of the septal region with c ompletely normal coronary angiograms. Electron microscopy of left vent ricular biopsies showed slight ultrastructural changes in the myocytes . In addition, large glycogen deposits were mostly associated with swo llen mitochondria, The patient was discharged in good clinical conditi on on day 10. Conclusions: Presence of glycogen deposits associated wi th abnormal mitochondria may be signs of the incapability of myocardia l cells in utilizing energy substrata, In the presence of normal myoca rdial perfusion, our findings are consistent with the presence of a st unned myocardium-like syndrome. Early recognition and treatment of thi s clinical syndrome allow the prevention of myocardial infarction.