Supraventricular Tachycardia as an Unusual Presentation of Infantile Onset Pompe Disease: A Case Report

Abstract

Pompe disease is a rare autosomal recessive lysosomal storage disorder with an incidence of approximately one in 40,000 live births is caused by deficiency of acid α-glucosidase, leading to progressive glycogen accumulation in cardiac and skeletal muscle. Infantile Onset Pompe Disease (IOPD) represents the most severe phenotype and usually presents within the first year of life with hypotonia and cardiomyopathy. An 11-month-old male infant third born of third-degree consanguinity, presented with irritability, lethargy, fast breathing and refusal of feeds. Clinical examination revealed a floppy infant with generalised hypotonia, proximal muscle weakness, absent deep tendon reflexes, with a peak heart rate of 280/min. Electrocardiography (ECG) revealed Supraventricular Tachycardia (SVT). SVT reverted with two doses of adenosine. Laboratory work-up of metabolic myopathies were within normal limits except for the Creatine Phosphokinase (CPK) which was elevated. Echocardiography revealed concentric left ventricular hypertrophy with severe systolic dysfunction. Genetic study identified a homozygous pathogenic variant in the GAA gene, confirming IOPD. The child was stabilised with anti-failure therapy and referred for enzyme replacement therapy. Unfortunately, infant succumbed in two weeks. Arrhythmias, including SVT, may be an early and intrinsic manifestation of the disease. Early recognition, genetic confirmation, vigilant cardiac monitoring, and timely initiation of enzyme replacement therapy are essential to improve survival and long-term outcomes in IOPD.