Recurrent Ventricular Tachycardia in Medium-Chain Acyl-Coenzyme A Dehydrogenase Deficiency

Area of Science:

• Biochemistry
• Genetics
• Pediatrics

Background:

• Medium-chain acyl-coenzyme A dehydrogenase (MCAD) deficiency is an inherited metabolic disorder.
• Cardiac complications, particularly arrhythmias, are considered less common in MCAD deficiency compared to other fatty acid oxidation disorders.

Purpose of the Study:

• To report a case of a neonate with MCAD deficiency presenting with severe metabolic disturbances and life-threatening ventricular arrhythmias.
• To discuss the potential role of accumulating metabolites in inducing cardiac arrhythmias in MCAD deficiency, especially in the neonatal period.

Main Methods:

• Clinical case report of a neonate diagnosed with MCAD deficiency.
• Monitoring of metabolic parameters (hypoglycemia, hyperammonemia), seizure activity, and cardiac rhythm.
• Review of existing literature on arrhythmias in MCAD deficiency.

Main Results:

• The patient presented with hypoglycemia, hyperammonemia, seizures, and recurrent pulseless ventricular tachycardia.
• Despite supportive care, including intravenous glucose, the patient experienced fatal ventricular tachycardia.
• This case represents the sixth reported instance of ventricular tachyarrhythmias in MCAD deficiency, with a predilection in neonates.

Conclusions:

• Ventricular tachyarrhythmias can be a significant and potentially fatal complication of MCAD deficiency in neonates.
• Accumulation of medium-chain acylcarnitines or other metabolites may trigger arrhythmias, irrespective of blood glucose levels.
• Neonates with MCAD deficiency require vigilant cardiac monitoring due to the risk of arrhythmias.