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Isolated Progressive Cardiac Conduction Disease

By

L. Brent Mitchell

, MD, Libin Cardiovascular Institute of Alberta, University of Calgary

Last review/revision Jan 2023
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Isolated progressive cardiac conduction disease (PCCD) refers to a group of genetic disorders that involve progressively worsening defects in cardiac conduction, including sinus node dysfunction, varying degrees of atrioventricular (AV) block and/or His-Purkinje system conduction delays or blocks.

PCCD may be

  • Structural: Accompanied or followed by structural heart disease (eg, congenital heart disease, cardiomyopathy)

  • Isolated: Occurring in a structurally normal heart

The most common form of PCCD associated with a cardiomyopathy is one in which mutations in LMNA are present (see Lamin A/C Cardiomyopathy Lamin A/C Cardiomyopathy (Cardiolaminopathy) Lamin A/C cardiomyopathies are genetic disorders causing dilated cardiomyopathy, a variety of arrhythmias, conduction disorders, and increased risk of sudden death. Diagnosis includes ECG, cardiac... read more . Some such patients present with an apparently structurally normal heart but subsequently develop cardiomyopathy.

Isolated PCCD patients typically present with early-onset (age < 50 years), progressive conduction system disease manifest as one or more of the following:

A degenerative form, in which the conducting system becomes sclerotic, has been referred to as Lenègre-Lev disease.

The disorder is manifest by ECG changes including prolonged PR interval, widened P wave, widened QRS complex, AV block, right bundle branch block, left anterior hemiblock, left posterior hemiblock, left bundle branch block, or nonspecific interventricular conduction block. Patients also have a higher risk of sudden death.

Patients should have cardiac imaging (eg, echocardiography, MRI) to detect any structural disorders. Patients without structural disease should have genetic testing, particularly if they have a family history of sudden cardiac death or of need for pacemaker implantation at a young age. If testing reveals a genetic abnormality, family members should be screened with ECG and genetic testing.

Treatment is with a pacemaker following the usual indications for pacemaker implantation, Indications for Permanent Pacemakers Indications for Permanent Pacemakers including third-degree AV block or symptomatic second-degree AV block. A consensus recommendation is that pacemakers may also be useful in patients with familial isolated PCCD who have bifascular block with or without first-degree AV block (1 General reference Isolated progressive cardiac conduction disease (PCCD) refers to a group of genetic disorders that involve progressively worsening defects in cardiac conduction, including sinus node dysfunction... read more ).

General reference

  • 1. Priori SG, Wilde AA, Horie M, et al: HRS/EHRA/APHRS Expert Consensus Statement on the diagnosis and management of patients with inherited primary arrhythmia syndromes: : document endorsed by HRS, EHRA, and APHRS in May 2013 and by ACCF, AHA, PACES, and AEPC in June 2013. Heart Rhythm 10:1932–1963, 2013. doi: 10.1016/j.hrthm.2013.05.014

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