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The pathology of the heart conduction system in congenital heart block

J M Suárez-Peñaranda1, J I Muñoz, M S Rodríguez-Calvo

  • 1Department of Pathology and Forensic Sciences, University of Santiago de Compostela, Hospital Clínico, Travesía de Choupana s/n, 15702 Santiago de Compostela, Spain. jsuarezp@usc.es

Journal of Clinical Forensic Medicine
|October 13, 2006
PubMed

Insights

This case report details a 51-year-old man with complete heart block, whose His bundle was replaced by fibrous tissue. This finding highlights a common pathology in heart block, distinct from other known cardiac conduction system diseases.

Area of Science:

  • Cardiology
  • Pathology
  • Medical Case Reports

Background:

  • Congenital complete heart block affects 1 in 2500-20,000 births, often presenting as an isolated condition with variable conduction system pathology.
  • Complete heart block necessitates permanent pacemaker implantation in many individuals.

Observation:

  • A 51-year-old man with a pacemaker for complete heart block developed endocarditis post-pacemaker battery replacement.
  • The patient experienced a poor prognosis, succumbing to septic shock three months later.

Findings:

  • Autopsy revealed a hypertrophic heart and thickened left ventricle.
  • Histopathology demonstrated normal sinus and atrioventricular nodes, but an interrupted His bundle replaced by fibrous tissue.
  • Absence of inflammatory signs in the conduction system was noted.

Implications:

  • This case illustrates that His bundle fibrosis is a primary pathological process in complete heart block.
  • The observed pathology differs from Lev's disease (distal atrioventricular bundle involvement) and Lenegre's disease (diffuse conduction system damage).
  • Understanding specific pathological patterns is crucial for diagnosing and managing heart block.

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