Dynamic estimation of cardiac repolarization characteristics during hypoglycemia in healthy and diabetic subjects

Abstract

Hypoglycemia is known to affect the repolarization characteristics of the heart, but the mechanisms behind these changes are not completely understood. We analyzed repolarization characteristics continuously from 22 subjects during normoglycemic period, transition period (blood glucose concentration decreasing) and hypoglycemic period from nine healthy controls (Healthy), six otherwise healthy type 1 diabetics (T1DM) and seven type 1 diabetics with disease complications (T1DMc). An advanced principal component regression (PCR)-based method was used for estimating ECG parameters beat-by-beat, and thus, continuous comparison between the repolarization characteristics and blood glucose values was made. We observed that hypoglycemia related ECG changes in the T1DMc group were smaller than changes in the Healthy and T1DM groups. We also noticed that when glucose concentration remained at a low level, the heart rate corrected QT interval prolonged progressively. Finally, a few minutes time lag was observed between the start of hypoglycemia and cardiac repolarization changes. One explanation for these observations could be that hypoglycemia related hormonal changes have a significant role behind the repolarization changes. This could explain at least the observed time lag (hormonal changes are slow) and the lower repolarization changes in the T1DMc group (hormonal secretion lowered in long duration diabetics).

Corrected QT Interval Prolongation during Severe Hypoglycemia without Hypokalemia in Patients with Type 2 Diabetes

“…It was suggested that altered neural regulation is considered as the cause of the prolongation of QTc interval during hypoglycemia [22]. Similar to previous studies, our study did not observe tachycardia and significant differences in their heart rates during the episodes of severe hypoglycemia compared to the recovered stage in spite of all patients not taking alpha and beta adrenergic bloking agent.…”

Electrocardiographic Signals and Swarm-Based Support Vector Machine for Hypoglycemia Detection

“…However, in another study, QT interval corrected using Fridericia formula statistically significantly increased during hypoglycemia. 29 As the number of participants developing hypoglycemia in our study and in the other three studies cited was relatively low, the comparison of these two heart rate-correction formulas for repolarization prolongation during hypoglycemia on a larger number of participants might warrant further study. Furthermore, compared with SBSR, which is swarmbased SVM-RBF, the performance of LMR was lower in terms of geometric mean: 75.87% vs. 65.86% (SBSR vs. LMR).…”

Association of hypoglycaemia and risk of cardiac arrhythmia in patients with diabetes mellitus: A systematic review and meta‐analysis

“…Our initial search yielded 4625 citations, of which 67 full texts were assessed for eligibility (Figure ). After examination, 24 publications from 21 studies were considered eligible . Duplicate publications of 3 studies were identified .…”

“…A total of 8 studies had an observational design, reporting outcomes among participants with T1DM (n = 5), with T2DM (n = 2) or with both (n = 1) . The remaining 12 studies involved experimentally induced hypoglycaemia in participants with T1DM (n = 6), with T2DM (n = 5) or with both (n = 1) . The definition of hypoglycaemia varied across studies.…”