Fig. 3From: Early diagnosis and management of cardiac manifestations in mucopolysaccharidoses: a practical guide for paediatric and adult cardiologistsMPS I in a 14-year-old male. a First-degree atrioventricular block: PR interval greater than 0.20 s. b Second-degree atrioventricular block type 1: progressive prolongation with dropped beat. The red arrows indicate the P waveBack to article page