AN IDDM PATIENT WHO COMPLAINED OF CHEST OPPRESSION WITH ISCHEMIC CHANGES ON ECG IN INSULIN-INDUCED HYPOGLYCEMIA

A 34-year-old female IDDM patient complained of chest oppression in hy poglycemic episodes and electrocardiograms revealed reversible ischemi c changes occuring concomitantly with hypoglycemia. The ECG changes im proved and the chest oppression disappeared following increasing blood glucose level by glucose intake. Master's double load test and treadm ill load test were positive for ischemic changes. Radioisotopic myocar dial scintigraphy by thallium and BMIPP did not show any filling defec ts and coronary angiography revealed no remarked stenosis in the coron ary arteries. She had no mitochondrial tRNA(Leu) (A --> G) gene mutati on at nucleotide position 3243, but both the patient and her mother ha d a G-to-A transition within the replication origin of the light stran d at nucleotide position 5744 of the mitochondrial gene. As the patien t's maternal family had no history of ischemic heart disease, it is no t clear whether mitochondrial gene mutation at nucleotide position 574 4 reflects the occurence of cardiac ischemia. Some disorders of microc irculation in capillary vessels in cardiac muscles may occur in such p atients. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.