Giant Heart of Classical Infantile-Onset Pompe Disease With Mirror Image Dextrocardia.

A 5-month-old male infant born to consanguinious marriage with past history of feeding difficulties in the form of suck-rest-suck cycle, forehead diaphoresis, and poor weight gain since early infancy presented with increasing severity of respiratory distress and apathy of 2 weeks duration. Physical examination revealed tachypnea, tachycardia, severe respiratory distress with chest wall retractions, and cool peripheries. The liver edge was palpable 4 cm below the left costal margin in midclavicular line. Neurological examination showed floppy infant appearence with generalized hypotonnia and absent deep tendon reflexes. Cardiovascular system examination revealed apex impulse in right 6th intercostal space near anterior axillary line, presence of gallop rhythm, and soft sys-tolic murmur. Chest X-ray (Figure A) was suggestive of visceral situs inversus, dextrocardia, cardiomegaly, and normal pulmonary vasculature. Electrocardiogram showed peaked P waves, severe right and left ventricular hypertrophy with ST-T changes. Echocardiography (Figure B–D; Video in the Data Supplement) showed severe concentric hypertrophy of left ventricle and pap-illary muscles, right ventricle free wall hypertrophy with almost complete obliteration of right ventricle cavity during systole, restrictive left ventricle filling pattern, mild mitral regurgita-tion, mild tricuspid regurgitation, no left ventricular or right ventricular outflow tract obstruction, and thin rim of pericardial effusion. Levels of lysosomal enzyme α-1, 4-glucosidase in leucocytes were grossly deficient: with acarbose,1.98 (normal range, 3.3–14.5 nmol/h/mg protein); without acarbose, 17.1 (normal range, 20.67–206.73 nmol/h/mg protein), and ratio of 0.11 (normal, >0.2). To summarize, this is a case of infantile-onset Pompe disease presenting with severe cardiomyopathy and generalized muscle weakness with marked biventricular hypertrophy, almost complete obliteration of ventricular cavity at the end systole with situs inversus and dextrocardia, which is probably not yet reported. Unfortunately, baby died because of cardiorespiratory failure at the age of 6 months, and parents declined postmortem examination. Discussion Pompe disease (Type II Glycogen storage disorder; OMIM 232300) is an autosomal recessive disorder with an incidence of ≈1/40,000 live births, caused by deficiency of lysosomal acid α-1, 4-glucosidase (GAA), resulting in lysosomal glycogen accumulation principally in cardiac, skeletal, and smooth muscle cells. Infantile-onset Pompe disease is characterized by a generalized muscle weakness, hypoto-nia, feeding difficulties, macroglossia, hepatomegaly, and a hypertrophic cardiomyopathy with death typically in the first year of life because of cardiorespiratory or respiratory failure. Late-onset Pompe disease (juvenile and adult forms) feature slowly progressive proximal muscle weakness without significant cardiomyopathy. Respiratory failure as a result of respiratory muscle involvement is the usual cause of death …