c-peptide and Arrhythmias--Cardiac

Persistent hyperinsulinemic hypoglycemia in neonatal period is characterized by insulin hypersecretion. The major feature is severe hypoglycemia, generally unresponsive to routine medical treatment. Subtotal or total pancreatectomy is performed in unresponsive cases. In this case report, we present a newborn with persistent hypoglycemia unresponsive to medical treatment with dysrhythmic left ventricular hypertrophy. The insulin/C-peptide ratio was 58 as a confirmation of diagnosis. Since hypoglycemia persisted after the initial medical treatment, a subtotal pancreatectomy was performed followed by near-total pancreatectomy. A histologic examination revealed diffuse insulin islets. At the 70th post-natal day, death occurred due to heart failure and ventricular dysrhythmia. To our knowledge, severe dysrhythmia and left ventricular hypertrophy in persistent hyperinsulinemic hypoglycemia (PPH) is identified in the patient.

Topics: Arrhythmias, Cardiac; C-Peptide; Congenital Hyperinsulinism; Fatal Outcome; Humans; Hypertrophy, Left Ventricular; Infant, Newborn; Insulin; Male; Pancreas; Pancreatectomy

Improved blood glucose control by insulin treatment in patients with Type 2 (non-insulin dependent) diabetes mellitus increases the risk for hypoglycaemic episodes. Our objective was to investigate if hypoglycaemia causes electrocardiographic changes and cardiac arrhythmias in patients with Type 2 diabetes. Six insulin-treated patients with Type 2 diabetes and no known cardiac disease took part in the study. Hypoglycaemia was induced by insulin infusion aiming at a plasma glucose less than or equal to 2.0 mmol l-1 or hypoglycaemic symptoms. All patients experienced hypoglycaemic symptoms. The median lowest arterial plasma glucose was 2.0 mmol l-1. Arterial plasma adrenaline concentration increased from 0.4 +/- 0.1 (mean +/- SE) to 6.9 +/- 0.3 nmol l-1 (p less than 0.001) while serum potassium was lowered from 4.1 +/- 0.3 mmol l-1 to 3.5 +/- 0.2 mmol l-1 (p less than 0.001). The heart rate increased significantly during hypoglycaemia except in one patient who developed hypoglycaemic symptoms and a severe bradyarrhythmia at a plasma glucose of 4.4 mmol l-1. One patient developed frequent ventricular ectopic beats during hypoglycaemia while four patients showed no arrhythmia. ST-depression in ECG leads V2 and V6 was observed during hypoglycaemia in five patients (p less than 0.05) and four patients developed flattening of the T-wave. In conclusion, the study supports the hypothesis that hypoglycaemia in patients with Type 2 diabetes may be hazardous by causing cardiac arrhythmias.

Topics: Arrhythmias, Cardiac; Blood Glucose; Blood Pressure; C-Peptide; Diabetes Mellitus, Type 2; Electrocardiography; Epinephrine; Fatty Acids, Nonesterified; Humans; Hypoglycemia; Insulin; Middle Aged; Norepinephrine; Potassium

A high incidence (40%) of cardiac arrhythmias was found in patients while on dialysis. This incidence was significantly higher than on nondialysis days. A comparison study of patients with significant cardiac arrhythmia and patients with cardiac arrhythmia was made. There was no difference in the echocardiogram, total body potassium, plasma renin activity, aldosterone, catecholamines, serum sodium, potassium and calcium between the two groups. Significant alkalinization occurred in all patients at the end of dialysis. Blood levels of total PTH and C peptide were higher in the arrhythmic patients versus the nonarrhythmic patients. No explanation was found as to why patients developed arrhythmias or what differentiated the two groups.

Topics: Adult; Aged; Arrhythmias, Cardiac; C-Peptide; Calcium; Catecholamines; Echocardiography; Electrocardiography; Humans; Kidney Failure, Chronic; Male; Middle Aged; Parathyroid Hormone; Potassium; Renal Dialysis; Renin-Angiotensin System; Sodium