QTc interval and scintigraphically assessed myocardial perfusion in newly diagnosed and long-term type 1 diabetes mellitus

Abstract In diabetes mellitus, heart rate corrected QT interval (QTc) has been suggested to be related to ischemic heart disease and increased risk of sudden cardiac death. The aim of the study was to analyze the length of QTc interval with regard to global and regional myocardial perfusion in type 1 diabetic patients. Myocardial perfusion was investigated in 20 newly diagnosed and 40 long-term type 1 diabetic patients without clinical evidence for coronary artery disease by means of Tc-99-methoxyisobutylisonitrile (Tc-99m-MIBI)-scintigraphy (myocardial uptake (MU) score: 1–6). Five consecutive RR and QT intervals of resting electrocardiogram (ECG) tracing were measured and corrected for the previous cycle length. ECG-based cardiac autonomic neuropathy (CAN) was assessed with five cardiac reflex tests. Length of QTc interval was 423±29 ms in newly diagnosed and 433±26 ms in long-term type 1 diabetic patients. Nine (45%) newly diagnosed and 18 (45%) long-term diabetic patients demonstrated a prolonged QTc interval (>440 ms). Both newly diagnosed and long-term diabetic patients did not display significant global or regional myocardial perfusion defects (mean MU scores p p p