Anatomic Characteristics of Extensions of Atrial Myocardium into the Pulmonary Veins in Subjects With and Without Atrial Fibrillation

2003 ◽  
Vol 26 (6) ◽  
pp. 1348-1355 ◽  
Author(s):  
IVANA KHOLOVÁ ◽  
JOSEF KAUTZNER
Author(s):  
Oleksandr S. Stychynskyi ◽  
Alina V. Topchii ◽  
Pavlo O. Almiz

According to modern concepts, atrial fibrillation (AF) occurs when there are triggers affecting the prepared substrate (atrial myocardium) in the presence of modulating factors that contribute to the occurrence of arrhythmia. Catheter treatment of AF has been most successfully developed in the field of affecting triggers (since late 1990s, the most successful was a technique of isolation of pulmonary veins which are the main source of trigger impulses in AF). Over the past two decades, various techniques have also been proposed for influencing the fibrous substrate. The aim. To analyze the most advanced techniques for influencing the fibrous substrate during catheter treatment of AF. Materials and methods. We analyzed the experience of leading electrophysiological centers in this field. Discussion. Modern studies contain various electrophysiological criteria of fibrous myocardium. However, the signal amplitude less than 0.5 mV is considered borderline between healthy and damaged tissues by most authors. The task of the catheter action on the myocardium is to separate the fibrously altered tissue and intact tissue. This can be achieved by isolating the area of fibrosis or by transforming it into a scar tissue incapable of arrhythmogenesis. It should be noted that both methods are associated with the same frequency of the absence of AF paroxysms, which can be regarded as confirmation of the advisability of influencing the substrate. The most important is that exposure of the substrate can significantly reduce the recurrence rate of AF compared to that when the ablation procedure is limited to isolation of the pulmonary veins. Conclusions. Modern methods of influencing the areas of fibrosis in the atria can significantly improve the results of catheter treatment of AF.


2002 ◽  
Vol 43 (4) ◽  
pp. 357-365 ◽  
Author(s):  
Hideko Nakashima ◽  
Koichiro Kumagai ◽  
Hideaki Tojo ◽  
Tomoo Yasuda ◽  
Hiroo Noguchi ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tatyana V. Sukhacheva ◽  
Natalia V. Nizyaeva ◽  
Maria V. Samsonova ◽  
Andrey L. Cherniaev ◽  
Artem A. Burov ◽  
...  

AbstractTelocytes are interstitial cells with long, thin processes by which they contact each other and form a network in the interstitium. Myocardial remodeling of adult patients with different forms of atrial fibrillation (AF) occurs with an increase in fibrosis, age-related isolated atrial amyloidosis (IAA), cardiomyocyte hypertrophy and myolysis. This study aimed to determine the ultrastructural and immunohistochemical features of cardiac telocytes in patients with AF and AF + IAA. IAA associated with accumulation of atrial natriuretic factor was detected in 4.3–25% biopsies of left (LAA) and 21.7–41.7% of right (RAA) atrial appendage myocardium. Telocytes were identified at ultrastructural level more often in AF + IAA, than in AF group and correlated with AF duration and mitral valve regurgitation. Telocytes had ultrastructural signs of synthetic, proliferative, and phagocytic activity. Telocytes corresponded to CD117+, vimentin+, CD34+, CD44+, CD68+, CD16+, S100-, CD105- immunophenotype. No significant differences in telocytes morphology and immunophenotype were found in patients with various forms of AF. CD68-positive cells were detected more often in AF + IAA than AF group. We assume that in aged AF + IAA patients remodeling of atrial myocardium provoked transformation of telocytes into “transitional forms” combining the morphological and immunohistochemical features with signs of fibroblast-, histiocyte- and endotheliocyte-like cells.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
Y Takahashi ◽  
T Kitai ◽  
T Watanabe ◽  
T Fujita

Abstract Background Low-voltage zone (LVZ) in the left atrium (LA) seems to represent fibrosis. LA longitudinal strain assessed by speckle tracking method is known to correlate with the extent of fibrosis in patients with mitral valve disease. Purpose We sought to identify the relationship between LA longitudinal strain and LA bipolar voltage in patients with atrial fibrillation (AF). We tested the hypothesis that LA strain can predict LA bipolar voltage. Methods A total of 96 consecutive patients undergoing initial AF ablation were analyzed. All patients underwent transthoracic echocardiography including 2D speckle tracking measurement on the day before ablation during sinus rhythm (SR group, N=54) or during AF (AF group, N=42). LA longitudinal strain was measured at basal, mid, and roof level of septal, lateral, anterior, and inferior wall in apical 4- and 2-chamber view. Global longitudinal strain (GLS) was defined as an average value of the 12 segments. LA voltage map was created using EnSite system, and global mean voltage was defined as a mean of bipolar voltage of the whole LA excluding pulmonary veins and left atrial appendage. LVZ was defined as less than 1.0 mV. Results There was a significantly positive correlation between GLS and global mean voltage (r=0.708, p<0.001). Multivariate regression analysis showed that GLS and age were independent predictors of global mean voltage. There was a significant negative correlation between global mean voltage and LVZ areas. Conclusions There was a strong correlation between LA longitudinal strain and LA mean voltage. GLS can independently predict LA mean voltage, subsequently LVZ areas in patients with AF. Funding Acknowledgement Type of funding source: None


2021 ◽  
Vol 10 (14) ◽  
pp. 3129
Author(s):  
Riyaz A. Kaba ◽  
Aziz Momin ◽  
John Camm

Atrial fibrillation (AF) is a global disease with rapidly rising incidence and prevalence. It is associated with a higher risk of stroke, dementia, cognitive decline, sudden and cardiovascular death, heart failure and impairment in quality of life. The disease is a major burden on the healthcare system. Paroxysmal AF is typically managed with medications or endocardial catheter ablation to good effect. However, a large proportion of patients with AF have persistent or long-standing persistent AF, which are more complex forms of the condition and thus more difficult to treat. This is in part due to the progressive electro-anatomical changes that occur with AF persistence and the spread of arrhythmogenic triggers and substrates outside of the pulmonary veins. The posterior wall of the left atrium is a common site for these changes and has become a target of ablation strategies to treat these more resistant forms of AF. In this review, we discuss the role of the posterior left atrial wall in persistent and long-standing persistent AF, the limitations of current endocardial-focused treatment strategies, and future perspectives on hybrid epicardial–endocardial approaches to posterior wall isolation or ablation.


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