Sudden Unexpected Death Associated with Arrhythmogenic Cardiomyopathy: Study of the Cardiac Conduction System

A retrospective study was conducted on pathologically diagnosed arrhythmogenic cardiomyopathy (ACM) from consecutive cases over the past 34 years (n = 1109). The anatomo-pathological analyses were performed on 23 hearts diagnosed as ACM (2.07%) from a series of 1109 suspected cases, while histopathological data of cardiac conduction system (CCS) were available for 15 out of 23 cases. The CCS was removed in two blocks, containing the following structures: Sino-atrial node (SAN), atrio-ventricular junction (AVJ) including the atrio-ventricular node (AVN), the His bundle (HB), the bifurcation (BIF), the left bundle branch (LBB) and the right bundle branch (RBB). The ACM cases consisted of 20 (86.96%) sudden unexpected cardiac death (SUCD) and 3 (13.04%) native explanted hearts; 16 (69.56%) were males and 7 (30.44%) were females, ranging in age from 5 to 65 (mean age ± SD, 36.13 ± 16.06) years. The following anomalies of the CCS, displayed as percentages of the 15 ACM SUCD cases in which the CCS has been fully analyzed, have been detected: Hypoplasia of SAN (80%) and/or AVJ (86.67%) due to fatty-fibrous involvement, AVJ dispersion and/or septation (46.67%), central fibrous body (CFB) hypoplasia (33.33%), fibromuscular dysplasia of SAN (20%) and/or AVN (26.67%) arteries, hemorrhage and infarct-like lesions of CCS (13.33%), islands of conduction tissue in CFB (13.33%), Mahaim fibers (13.33%), LBB block by fibrosis (13.33%), AVN tongue (13.33%), HB duplicity (6.67%%), CFB cartilaginous meta-hyperplasia (6.67%), and right sided HB (6.67%). Arrhythmias are the hallmark of ACM, not only from the fatty-fibrous disruption of the ventricular myocardium that accounts for reentrant ventricular tachycardia, but also from the fatty-fibrous involvement of CCS itself. Future research should focus on application of these knowledge on CCS anomalies to be added to diagnostic criteria or at least to be useful to detect the patients with higher sudden death risks.

Download Full-text

Sudden Unexpected Death Associated with Arrhythmogenic Cardiomyopathy: Study of the Cardiac Conduction System

10.20944/preprints202106.0246.v1 ◽

2021 ◽

Author(s):

Giulia Ottaviani ◽

Graziella Alfonsi ◽

Simone G. Ramos ◽

Anna M. Lavezzi ◽

L. Maximilian Buja

Keyword(s):

Fibromuscular Dysplasia ◽

Ventricular Myocardium ◽

Conduction System ◽

Cardiac Conduction ◽

Careful Examination ◽

Cardiac Conduction System ◽

Arrhythmogenic Cardiomyopathy ◽

Unexpected Death ◽

The Past ◽

The Right

A retrospective study was conducted on pathologically diagnosed arrhythmogenic cardiomyopathy (ACM) from consecutive cases over the past 34 years (n = 1,109). The cardiac conduction system (CCS) was removed in two blocks, containing the following structures: Sino-atrial node (SAN), atrio-ventricular junction (AVJ) including the atrio-ventricular node (AVN), the His bundle (HB), the bifurcation (BIF), the left bundle branch (LBB) and the right bundle branch (RBB). The ACM cases (2.07% of the total cases) consisted of 20 (86.96%) sudden unexpected cardiac death (SUCD) and 3 (13.04%) native explanted hearts; 16 (69.56%) were males and 7 (30.44%) were females, ranging in age from 5 to 65 (mean age ± SD, 36.13 ± 16.06) years. The following anomalies of the CCS, displayed as percentages of ACM SUCD cases, have been detected: Hypoplasia of SAN (80%) and/or AVJ (86.67%) due to fatty-fibrous involvement, AVJ dispersion and/or septation (46.67%), central fibrous body (CFB) hypoplasia (33.33%), fibromuscular dysplasia of SAN (20%) and/or AVN (26.67%) arteries, hemorrhage and infarct-like lesions of CCS (13.33%), islands of conduction tissue in CFB (13.33%), Mahaim fibers (13.33%), LBB block by fibrosis (13.33%), AVN tongue (13.33%), HB duplicity (6.67%%), CFB cartilaginous meta-hyperplasia (6.67%), and right sided HB (6.67%). Arrhythmias are the hallmark of ACM, not only from the fatty-fibrous disruption of the ventricular myocardium that accounts for reentrant ventricular tachycardia, but also from the fatty-fibrous involvement of CCS itself. The careful examination of the cardiac conduction system on serial sections was crucial in documenting the fatty-fibrous infiltration of CCS in ACM.

Download Full-text

Vascularization fo the cardiac conduction system in humans by the right coronary artery

The FASEB Journal ◽

10.1096/fasebj.22.1_supplement.586.4 ◽

2008 ◽

Vol 22 (S1) ◽

Author(s):

Patricia M Herrera ◽

Adelina Rojas ◽

Carlos F. Cichero ◽

Adrián J. Barceló ◽

Manuel Arteaga ◽

...

Keyword(s):

Coronary Artery ◽

Right Coronary Artery ◽

Conduction System ◽

Cardiac Conduction ◽

Cardiac Conduction System ◽

The Right

Download Full-text

Development of the cardiac conduction system

ESC CardioMed ◽

10.1093/med/9780198784906.003.0008_update_001 ◽

2018 ◽

pp. 49-52

Author(s):

Jan Hendrik van Weerd ◽

Vincent M. Christoffels

Keyword(s):

Regulatory Networks ◽

Atrioventricular Node ◽

Ventricular Myocardium ◽

Conduction System ◽

Cardiac Conduction ◽

Cardiac Conduction System ◽

Cellular Mechanisms ◽

Fibre Network ◽

Electrical Impulses ◽

And Function

The contraction of the heart is orchestrated by the components of the cardiac conduction system (CCS), which initiate and propagate the electrical impulses to coordinately activate the cardiac chambers. In the adult heart, the impulse is generated in the sinoatrial node and activates the atrial myocardium. Slow conduction of the impulse through the atrioventricular node allows for emptying of the atria and filling of the ventricles prior to ventricular contraction. Subsequent fast conduction through the atrioventricular bundle, bundle branches, and Purkinje fibre network activates the ventricular myocardium and causes the ventricles to contract. The development and function of the CCS involves complex regulatory networks of transcription factors acting in stage-, tissue-, and dose-dependent manners. Disrupted function or expression of these factors might lead to impaired development or function of the CCS components, associated with heart failure and sudden death. It is therefore crucial to understand the molecular and cellular mechanisms controlling the complex regulation of CCS development. This chapter summarizes current insight in the development and function of the different compartments of the CCS, and discusses the transcriptional networks underlying these processes.

Download Full-text