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Published on: July 5, 2021
Heparan sulfate storage in the cardiac conduction system triggers atrioventricular block
Rie Kato1, Hiroaki Miyahara2, Tatsuya Kawano2
1Department of Pediatrics and Child Neurology, Oita University School of Medicine, Yufu, Oita 8795593, Japan; Department of Pediatrics and Child Neurology, Beppu Developmental Medical Center for Cerebral Palsy, Mental Retardation and Severely Handicapped Children, Beppu, Oita 8740838, Japan.
Insights
Heparan sulfate (HS) accumulation in the cardiac conduction system (CCS) may cause atrioventricular (AV) block. This study highlights HS
Area of Science:
- Biochemistry
- Cardiology
- Genetics
Background:
- Heparan sulfate (HS) is a complex polysaccharide with diverse biological roles.
- Sanfilippo syndrome type A is a lysosomal storage disorder affecting HS metabolism.
- Cardiac conduction system (CCS) disorders, like atrioventricular (AV) block, can have various underlying causes.
Objective:
To elucidate the novel biological functions of heparan sulfate (HS) by clinic-pathologically studying a patient with paroxysmal atrioventricular (AV) block.
Patient:
A long-surviving male patient with Sanfilippo syndrome type A presented with paroxysmal AV block at age 33years. He then survived another 2.5years after the onset of paroxysmal AV block and pacemaker implantation.
Methods And Results:
His cardiac histopathological examination at autopsy showed HS storage in the cardiac conduction system (CCS), especially in the atrioventricular node (AVN)-His bundle branches.
Conclusion:
HS storage in the CCS might trigger AV block, arising from below the AVN-His bundle branches. This is the first description to indicate that HS might be an essential constituent of life-long CCS plasticity and that its storage in the CCS results in AV block.
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