Anatomy of the conduction tissues 100 years on: what have we learned?

Heart ◽  
2021 ◽  
pp. heartjnl-2021-320304
Author(s):  
Damián Sánchez-Quintana ◽  
Robert H Anderson ◽  
Justin T Tretter ◽  
José Angel Cabrera ◽  
Eduardo Back Sternick ◽  
...  

Knowledge of the anatomy of the ‘conduction tissues’ of the heart is a 20th century phenomenon. Although controversies still continue on the topic, most could have been avoided had greater attention been paid to the original descriptions. All cardiomyocytes, of course, have the capacity to conduct the cardiac impulse. The tissues specifically described as ‘conducting’ first generate the cardiac impulse, and then deliver it in such a fashion that the ventricles contract in orderly fashion. The tissues cannot readily be distinguished by gross inspection. Robust definitions for their recognition had been provided by the end of the first decade of the 20th century. These definitions retain their currency. The sinus node lies as a cigar-shaped structure subepicardially within the terminal groove. There is evidence that it is associated with a paranodal area that may have functional significance. Suggestions of dual nodes, however, are without histological confirmation. The atrioventricular node is located within the triangle of Koch, with significant inferior extensions occupying the atrial vestibules and with septal connections. The conduction axis penetrates the insulating plane of the atrioventricular junctions to continue as the ventricular pathways. Remnants of a ring of cardiomyocytes observed during development are also to be found within the atrial vestibules, particularly a prominent retroaortic remnant, although that their role has still to be determined. Application of the initial criteria for nodes and tracts shows that there are no special ‘conducting tissues’ in the pulmonary venous sleeves that might underscore the abnormal rhythm of atrial fibrillation.

2005 ◽  
Vol 4 (2) ◽  
pp. 51-57
Author(s):  
DW Davies ◽  
◽  
MD O’Neill ◽  

Narrow complex tachycardia usually refers to an abnormality of cardiac rhythm involving the tissues of the sinus node, atrial tissue, the atrioventricular node or an accessory atrioventricular communication. Although atrial fibrillation is the most common supraventricular arrhythmia, the term “supraventricular tachycardia” conventionally refers to the group of rhythm disturbances encompassing sinus tachycardia (appropriate and inappropriate), atrial tachycardia, atrial flutter, atrioventricular nodal reciprocating tachycardia (AVNRT) and atrioventricular reciprocating tachycardia (AVRT) including the Wolff Parkinson White syndrome (WPW). Atrial fibrillation is beyond the scope of this article which focuses on the diagnosis and acute management of the patient presenting with one of these common causes of a regular, narrow complex tachycardia.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
L Wu ◽  
B Narasimhan ◽  
A.N Shah ◽  
Y.Y Zheng ◽  
K Bhatia ◽  
...  

Abstract Introduction Atrial fibrillation (AF) ablation and Atrioventricular Node (AVN) ablation are both important non-pharmacological therapy of AF. In spite of increased availability of AF ablation data, that of AVN ablation per se is limited. Method AF ablation was identified using ICD-9 procedure code with principle diagnosis of AF from United States National Inpatient Sample database 2005–2014. From procedure and diagnosis codes of pacemaker insertion followed by ablation, the cohort who underwent AVN ablation was identified. Patients hospitalization with any diagnosis of other type of arrythmia or epicardial ablation were excluded. Complications were defined as per the Agency for Health Care Research and Quality guideline. Results Total AF ablation was noted to increase from 2005- 2011, and declined steadily from 2011–2014. In contrast, the number of AVN ablations increased from 4505 cases to 5175 (Figure 1). AVN ablation were mainly performed in elderly patient (mean age 72), and increasingly in patient with higher Charlson Commobidity index (0.9 to 1.7)and higher CHA2DS2-VASc score (2.8 to 3.7) (Table 1). An increasing trend in procedure complications but no significant change in mortalitywere observed with AVN ablation. Progressive increase in the length of stay and the hospitalization cost were also observed over the years with AVN ablation. Conclusion AVN ablation is being performed at a steady volume, and increasingly in patients with multiple comorbidities. This trend although was not associated with increased mortality, it was associated with increased hospital complications. Funding Acknowledgement Type of funding source: None


2010 ◽  
Vol 34 (2) ◽  
pp. 163-170 ◽  
Author(s):  
GANG CHEN ◽  
JIAN ZENG DONG ◽  
XING PENG LIU ◽  
XIN YONG ZHANG ◽  
DE YONG LONG ◽  
...  

2011 ◽  
Vol 141 (6) ◽  
pp. 1455-1460 ◽  
Author(s):  
Yoshiharu Soga ◽  
Hitoshi Okabayashi ◽  
Yoshio Arai ◽  
Takuya Nomoto ◽  
Jota Nakano ◽  
...  

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