Comparative Evaluation of Corrected QT and Ionized Calcium in Children

Area of Science:

• Pediatric Neurology
• Clinical Cardiology
• Pediatric Endocrinology

Background:

• Pediatric convulsions are a common clinical issue.
• Hypocalcemia is a frequent underlying cause of seizures in children.
• Electrocardiogram (EKG) corrected QT (QTc) interval prolongation is associated with hypocalcemia.

Purpose of the Study:

• To investigate the correlation between QTc interval and serum ionized calcium levels in pediatric convulsion.
• To evaluate the utility of QTc interval as a screening tool for hypocalcemia in children with seizures.

Main Methods:

• A study was conducted in 2008 involving 75 pediatric patients divided into three groups: first seizure, multiple seizures, and control (no seizure).
• Measurements included QTc interval, serum ionized calcium, total calcium, arterial blood gas (ABG), and serum albumin.
• Data were collected from the Department of Pediatrics at Imam Khomeini Hospital and Ahari Children's Medical Center.

Main Results:

• Prolonged QTc intervals were observed in 72% of children with convulsions versus 19% in the non-convulsive group.
• Serum ionized calcium levels were significantly lower in the convulsive group compared to the non-convulsive group.
• A significant inverse correlation was found between prolonged QTc and low serum ionized calcium, but not with total calcium.

Conclusions:

• Prolonged QTc interval is a prevalent finding in pediatric convulsion, strongly associated with hypocalcemia.
• QTc interval measurement serves as a simple, rapid, and effective method for evaluating serum ionized calcium levels in pediatric patients.
• This EKG parameter can aid in the early identification of hypocalcemia as a cause of seizures in children.