Anatomy, histology, and pathology of the cardiac conduction system—part III

Waller, Bruce F.; Gering, Lawrence E.; Branyas, Nancy A.; Slack, John D.

doi:10.1002/clc.4960160513

Cited by 12 publications

(4 citation statements)

References 35 publications

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“…However, the cause of a dysfunctional conduction system in MMD is yet to be determined. Myocardial fibrosis can affect the structural integrity and electrical conductive properties of cardiac muscle leading to heart failure and arrhythmias [28, 29]. However, the association between myocardial fibrosis and surface conduction abnormalities in MMD1 has not been well defined and contrasting evidence exists in this regard [10, 11].…”

Section: Discussionmentioning

confidence: 99%

Myocardial fibrosis by late gadolinium enhancement cardiovascular magnetic resonance in myotonic muscular dystrophy type 1: highly prevalent but not associated with surface conduction abnormality

Cardona

Arnold

Kissel

et al. 2019

Journal of Cardiovascular Magnetic Resonance

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Background Conduction disease and arrhythmias represent a major cause of mortality in myotonic muscular dystrophy type 1 (MMD1). Permanent pacemaker (PPM) implantation is the cornerstone of therapy to reduce cardiovascular mortality in MMD1. Cardiovascular magnetic resonance (CMR) studies demonstrate a high prevalence of myocardial fibrosis in MMD1, however the association between CMR myocardial fibrosis with late gadolinium enhancement (CMR-LGE) and surface conduction abnormality is not well established in MMD1. We investigated whether myocardial fibrosis by CMR-LGE is associated with surface conduction abnormalities meeting criteria for PPM implantation according to current guidelines in a cohort of patients with genetically confirmed MMD1. Methods Patients with genetically confirmed MMD1 were retrospectively evaluated. 12-lead electrocardiography (ECG) performed within 6 months of CMR was necessary for inclusion. The severity and extent of MMD1 was quantified using a validated Muscular Impairment Rating Scale (MIRS). Based on current guidelines for device-based therapy of cardiac rhythm abnormalities, we defined surface conduction abnormality as the presence of ECG alterations meeting criteria for PPM implant (class I or II indications): PR interval > 200 ms (type I atrioventricular (AV) block) and/or mono or bifascicular block (QRS > 120 ms), or evidence of advanced AV block. Balanced steady-state free precession sequences (bSSFP) were used for assessment of left ventricular (LV) volumes and ejection fraction. MOdified Look-Locker Inversion Recovery (MOLLI) acquisition schemes were used to acquire T1 maps. Patients’ charts were reviewed up to 12 months post-CMR for occurrence of PPM implantation. Results Fifty-two patients (38% male, 41 ± 14 years) were included. Overall, 31 (60%) patients had a surface conduction abnormality and 22 (42%) demonstrated midwall myocardial fibrosis by CMR-LGE. After a median of 57 days from CMR exam, 15 patients (29%) underwent PPM implantation. Subjects with vs. without surface conduction abnormality had significantly longer disease length (15.5 vs. 7.8 years, p = 0.015) and higher disease severity on the MIRS scale ( p = 0.041). High prevalence of myocardial fibrosis by CMR-LGE was detected in subjects with and without surface conduction abnormality with no significant difference between the two cohorts (42% vs. 43%, p = 0.999). By multivariate logistic regression analysis, disease length was the only independent variable associated with surface conduction abnormality (OR 1.071, 95%CI 1.003–1.144, p = 0.040); while CMR-LGE was not associated with conduction abnormality (ρ = − 0.009, p = 0.949). Conclusions Myocardial fibrosis by CMR-LGE is highly prevalent in MMD1 but not related to surface conduction abnormality meeting current...

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Section: Discussionmentioning

confidence: 99%

Myocardial fibrosis by late gadolinium enhancement cardiovascular magnetic resonance in myotonic muscular dystrophy type 1: highly prevalent but not associated with surface conduction abnormality

Cardona

Arnold

Kissel

et al. 2019

Journal of Cardiovascular Magnetic Resonance

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“…5 The etiology of AVB in the setting of STEMI is thought to be multifactorial and dependent on the location of the culprit lesion. [6][7] The AV nodal artery normally arises from the right coronary artery. 8 and the ischemic insult caused by STEMI is thought to be sufficient to cause a transient dysfunction of the conduction fibers.…”

Section: Discussionmentioning

confidence: 99%

Study of Prognosis of Atrioventricular Blocks Versus Intraventricular Blocks in Acute Myocardial Infarction

Reddy¹,

Prasad²,

Prabhakar³

et al. 2016

jemds

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Myocardial infarction is a Global epidemic, and it is as large as the new epidemic afflicting population worldwide. According to the National Commission on Macro-economics and Health, there would be around 62 million patients with Coronary Artery Disease (CAD) by 2015 in India, and of these, 23 million would be younger than 40 years of age. 1 The present study will enlighten the correlation of Atrioventricular conduction defects versus intraventricular conduction defects in acute myocardial infarction after thrombolytic era. AIMS AND OBJECTIVESTo study the prognosis of atrioventricular conduction blocks versus intraventricular conduction defects in patients with acute myocardial infarction. MATERIALS AND METHODSIt is a prospective and comparative cohort study; 72 patients admitted in RLJH diagnosed as acute myocardial infarction who are with AV conduction blocks and myocardial infarction with intraventricular conduction blocks are included in the study. That is 36 patients with acute myocardial infarction with atrioventricular conduction blocks compared with 36 patients of myocardial infarction with intraventricular conduction blocks. Seven days followup is done to assess the prognosis of AV blocks versus intraventricular conduction blocks in acute myocardial infarction. RESULTSBoth AV (75%) and intraventricular (80%) blocks (IV blocks) are more in males, but no significant difference between AV and IV blocks with respect to gender. Chest pain (86%) is the common presentation for conduction disturbances in acute Myocardial Infarction (MI). Breathlessness is more specific for intraventricular blocks in acute MI. Anterior wall (52.8%) is involved in intraventricular conduction blocks compared to AV Blocks (27.8%). Inferior wall (55.6%) is involved in AV blocks more than anterior Wall (41.7%). In Killips staging most of AV blocks presented in stage 3 compared to IV block which have less risk (Stage 1) and better prognosis. Based on mortality AV blocks have more mortality of 33.3% compared to Intraventricular blocks (8.3%) in acute Myocardial Infarction (MI). CONCLUSIONHence taking all things together AV blocks are associated with greater risk or poor prognosis compared to intraventricular blocks in acute myocardial infarction according to this present study. A cross sectional study of the nutrient intake of rural Adolescent girls was carried out in four villages

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“…At the gross morphology level, the major pathways of conduction system have been traced and identified by numerous investigations (23,24). However, even the major pathways vary greatly among different persons.…”

Section: Simulation Of Voxel Modelmentioning

confidence: 99%