QTc and QTd in Children with Type 1 Diabetes Mellitus during Diabetic Ketoacidosis

Burden of arrhythmias and associated in-hospital mortality in acute decompensated diabetes mellitus

To gain understanding of the burden of cardiac arrhythmias in patients with acutely decompensated diabetes mellitus (ADDM) on a large scale, we reviewed data on ADDM patients and subtypes of arrhythmias from the National Inpatient Sample from 2010 to 2014. The frequency and prevalence of cardiac arrhythmias were measured, as well as outcomes. Among 874,107 hospitalized ADDM patients identified, 87,970 (10.1%) developed arrhythmias. The ADDM-arrhythmia cohort showed higher all-cause mortality (1.4% vs 0.3%; adjusted odds ratio 2.58, 95% confidence interval 2.39-2.79, P < 0.001), prolonged hospital stays (4.2 ± 4.8 vs 3.3 ± 3.4 days), and higher hospital charges ($32,609 vs $23,741) compared to those without arrhythmias (P < 0.001). The prevalence of supraventricular arrhythmia (atrial fibrillation, supraventricular tachycardia, and atrial flutter) and ventricular arrhythmia (ventricular tachycardia and ventricular fibrillation) was 2965 and 446 per 100,000 ADDM-related hospitalizations, respectively. The prevalence of any arrhythmias and atrial fibrillation in ADDM patients increased by 20.4% and 38.1%, respectively. The highest increase in the prevalence of arrhythmia among ADDM patients was observed in adults aged 18 to 44 years (22.5%).

QTc Prolongation in Pediatric Patients with Diabetic Ketoacidosis

OBJECTIVE

To investigate the association between diabetic ketoacidosis (DKA) and prolonged QTc interval and to assess for correlation between DKA severity and QTc prolongation.

STUDY DESIGN

Retrospective observational study in a pediatric hospital. Patients admitted with DKA diagnosed by laboratory criteria and an electrocardiogram (ECG) performed during a period of acidosis were identified using Looking Glass Clinical Analytics. Data including age, sex, pH, electrolytes, anion gap, and ECG variables were collected. Patients were excluded if they had a prior diagnosis of prolonged QTc or were taking QTc prolonging medications. Severity of DKA was classified as mild (pH 7.24-7.3), moderate (pH 7-7.24), or severe (pH <7). ECGs were read by a pediatric electrophysiologist and QTc interval was manually calculated utilizing the Bazett formula.

RESULTS

Ninety-six patients were included (mean age 15.2 ± 4.2 years, pH 7.12 ± 0.12, bicarbonate 8.6 ± 3.7 mmol/L, potassium 5.3 ± 1.1 mEq/L). Mean QTc interval for all patients in DKA was 454 ± 32 msec. Mean QTc in the mild group was 441 ± 22 msec, moderate group 460 ± 36 msec, and severe group 461 ± 34 msec. There was a significant difference in QTc interval across DKA severity groups (P = .05). There was a significant association between higher anion gaps and greater QTc intervals (r = 0.21, P = .04).

CONCLUSIONS

Thirty-one percent of pediatric patients with DKA demonstrated QTc prolongation on ECG. Severity of DKA and worsening acidosis were associated with increased prolongation of the QTc. Further study is required to evaluate the clinical impact of these findings.

The Heart in Diabetic Ketoacidosis: A Narrative Review Focusing on the Acute Cardiac Effects and Electrocardiographic Abnormalities

Diabetic ketoacidosis (DKA) is a serious complication of diabetes mellitus. Hyperglycemia, acidosis, and electrolyte imbalances can directly affect the heart by inducing toxicity, impairing myocardial blood flow, autonomic dysfunction, and altering activation and conduction of electrical impulses throughout the heart, increasing the risk of arrhythmias and ischemia. The electrocardiogram is useful in monitoring patients during and after an episode of DKA, as it allows the detection of arrhythmias and guides metabolic correction. Unfortunately, reports on electrocardiographic abnormalities in patients with DKA are lacking. We found two electrocardiographic patterns that are frequently reported in the literature: a pseudo-myocardial infarction and a Brugada Phenocopy. Both are associated with DKA metabolic anomalies and they resolve after treatment. Because of their clinical relevance and the challenge they represent for clinicians, we analyzed the clinical characteristics of these patients and the mechanisms involved in these electrocardiographic findings.

Electrocardiographic changes in children with diabetic ketoacidosis and ketosis

Aim

We aimed to study electrocardiographic changes in children with diabetic ketoacidosis and ketosis and to evaluate the relation of the changes with serum electrolyte levels and ketosis.

Material and Methods

This study was performed in Istanbul Medical Faculty, Pediatric Emergency and Intensive Care Department between May 2008 and May 2009. The electrocardiographic parameters and QT length of children with diabetic ketoacidosis and ketosis were evaluated at diagnosis and after the treatment.

Results

Forty patients were included in the study; 16 (40%) were diagnosed as having diabetic ketosis and 24 (60%) had diabetic ketoacidosis. Twenty-four (60%) patients were male and 16 (40%) were female and the mean age was 9.21±4.71 years (range, 1-16 years). Twelve (30%) cases of diabetic ketoacidosis were mild, three (7.5%) were moderate, and nine (22.5%) were severe. One patient had premature ventricular beats, and four had ST depression. The electrocardiographic parameters were all normal beyond the QTC length prolongation. The mean QTC length was 447±45 ms (380-560 ms) at diagnosis and 418±32 ms (350-500 ms) after treatment. The change in the QTC length was statistically significant. None of the patients had significant electrolyte disturbance and the prolongation of QTc length was not correlated with serum electrolyte levels. The prolongation of QTc length was statistically correlated with anion gap (r=0.33, p=0.03).

Conclusions

In our study, we showed QTc length prolongation and the importance of performing electrocardiography during the diagnosis of diabetic ketoacidosis and ketosis. We also demonstrated that ketosis was responsible for the prolongation of QTc length.

Dispersion durations of P-wave and QT interval in children treated with a ketogenic diet

BACKGROUND

Limited data are available on the effects of a ketogenic diet on dispersion duration of P-wave and QT-interval measures in children. We searched for the changes in these measures with serial electrocardiograms in patients treated with a ketogenic diet.

METHODS

Twenty-five drug-resistant patients with epilepsy treated with a ketogenic diet were enrolled in this study. Electrocardiography was performed in all patients before the beginning and at the sixth month after implementation of the ketogenic diet. Heart rate, maximum and minimum P-wave duration, P-wave dispersion, and maximum and minimum corrected QT interval and QT dispersion were manually measured from the 12-lead surface electrocardiogram.

RESULTS

Minimum and maximum corrected QT and QT dispersion measurements showed nonsignificant increase at month 6 compared with baseline values. Other previously mentioned electrocardiogram parameters also showed no significant changes.

CONCLUSIONS

A ketogenic diet of 6 months' duration has no significant effect on electrocardiogram parameters in children. Further studies with larger samples and longer duration of follow-up are needed to clarify the effects of ketogenic diet on P-wave dispersion and corrected QT and QT dispersion.

QT and JT dispersion and cardiac performance in children with neonatal Bartter syndrome: a pilot study

BACKGROUND

QT dispersion and JT dispersion are simple noninvasive arrhythmogenic markers that can be used to assess the homogeneity of cardiac repolarization. The aim of this study was to assess QT and JT dispersion and their relation with left ventricular systolic and diastolic functions in children with Bartter syndrome (BS).

METHODS

Nine neonatal patients with BS (median age 9.7 years) and 20 controls (median age 8 years) were investigated at rest. Both study and control subjects underwent electrocardiography (ECG) in which the interval between two R waves and QT intervals, corrected QT, QT dispersion, corrected QT dispersion, JT, corrected JT, JT dispersion and corrected JT dispersion were measured with 12-lead ECG. Two-dimensional, Doppler echocardiographic examinations were performed.

RESULTS

Patients and controls did not differ for gender and for serum levels of potassium, magnesium, and calcium (p > 0.05). Both study and control subjects had normal echocardiographic examination and baseline myocardial performance indexes. The QT dispersion and JT dispersion were significantly prolonged in patients with BS compared to those of the controls {37.5 ms [interquartile range (IQR) 32.5-40] vs. 25.5 ms (IQR 20-30), respectively, p = 0.014 and 37.5 ms (IQR 27.5-40) vs. 22.5 ms (IQR 20-30), respectively, p = 0.003}.

CONCLUSIONS

Elevated QT and JT dispersion during asymptomatic and normokalemic periods may be risk factors for the development of cardiac complications and arrhythmias in children with BS. In these patients the need for systematic cardiac screening and management protocol is extremely important for effective prevention.