scholarly journals Identification of novel pulmonary vein nodes as generators of ectopic arrhythmic foci for atrial fibrillation: An immuno-histochemical proof

2021 ◽  
Author(s):  
Tulika Gupta ◽  
Mandeep Kaur ◽  
Daisy Sahni

Introduction: The atrial muscle sleeve (AMS) of the pulmonary vein is the most common source of the arrhythmogenic triggers in atrial fibrillation (AF). Anatomical substrate generating these ectopic currents is still elusive. The present study was designed to study the AMS of pulmonary veins with an emphasis on the structural basis which might govern AF initiation and perpetuation. Materials and Methods: The study was conducted on longitudinal tissue section of pulmonary vein, taken from 15 human cadaveric non-diseased hearts. Tissue was studied histologically using H&E and Gomori trichrome stain. The pacemaker channels were identified by immunohistochemistry using monoclonal HCN4 and HCN1 antibodies. Results: The AMS was identified in each pulmonary vein, located between the tunica adventitia and tunica media. A node like arrangement of myocytes was seen within the AMS in 30% of veins. It had a compact zone limited by a fibrous capsule and contained much smaller, paler and interconnected myocytes. Outside the capsule there was a zone of dispersed, singly placed myocytes separating the compact zone from the working myocytes of the AMS. HCN4 and HCN1 antibodies were expressed on the cell membrane of nodal myocytes, while the working myocytes demonstrated none to minimal staining. Conclusion: Pulmonary veins nodes are similar to the specialized cardiac conductive tissue in, histological arrangement of compact and transitional zones, cellular characteristics, and the presence of pacemaker channels. They might be the anatomical basis of ectopic arrhythmogenic foci. To our knowledge these nodes are being described for the first time in human.

2016 ◽  
Vol 2016 ◽  
pp. 1-4
Author(s):  
John J. Lee ◽  
Denis Weinberg ◽  
Rishi Anand

Pulmonary vein stenosis is a well-established possible complication following an atrial fibrillation ablation of pulmonary veins. Symptoms of pulmonary vein stenosis range from asymptomatic to severe exertional dyspnea. The number of asymptomatic patients with pulmonary vein stenosis is greater than originally estimated; moreover, only about 22% of severe pulmonary vein stenosis requires intervention. We present a patient with severe postatrial fibrillation (AF) ablation pulmonary vein (PV) stenosis, which was seen on multiple imaging modalities including cardiac computed tomography (CT) angiogram, lung perfusion scan, and pulmonary angiogram. This patient did not have any pulmonary symptoms. Hemodynamic changes within a stenosed pulmonary vein might not reflect the clinical severity of the obstruction if redistribution of pulmonary artery flow occurs. Our patient had an abnormal lung perfusion and ventilation (V/Q) scan, suggesting pulmonary artery blood flow redistribution. The patient ultimately underwent safe repeat atrial fibrillation ablation with successful elimination of arrhythmia.


Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Troy J Badger ◽  
Robert S Oakes ◽  
Akram Shabaan ◽  
Nazem W Akoum ◽  
Nathan M Segerson ◽  
...  

Background. A mechanism of atrial fibrillation (AF) recurrence following ablation may be incomplete pulmonary vein antrum (PVA) scarring that allows for conduction between the pulmonary veins (PV) and the left atrium (LA). We report the relationship between circumferential PV scarring detected by delayed enhancement MRI (DE-MRI) and AF recurrence following PVAI. Methods. Eighty-six patients presenting for PVAI underwent DE-MRI 3 months post ablation. Circumferential ablation with posterior wall debulking was performed in all patients. PV ostia were marked on 3D images generated from the MRI data and assessed by consensus of two independent reviewers for the extent of scarring. Complete PVA scarring was defined as a continuous ring of enhancement surrounding the PVA. For patients with incomplete scarring, the degree of scarring was estimated. Results. The figure shows two patients from the cohort, Patient 1 exhibits successful scarring of all PVA. Patient 2 shows scarring of 1 PVA. At three months post ablation, complete circumferential lesion was seen on 131/335 PVA (39.1%). Complete scarring of 4 PVA was seen in 9 patients (10.5%), scarring of 3 PVA in 11 patients (12.8%) and scarring of 2 PVA was seen in 17 patients (19.8). Twenty-nine patients (33.7%) exhibited complete scarring in 1 PVA while 20 patients (23.3%) exhibited scarring in 0 PVA. Kaplan Meier analysis (Figure [E] ), suggests that PVA isolation may be important for long-term procedural success. Conclusion: Complete pulmonary vein antrum scarring exists in a very limited number of patients, despite its apparent importance for long-term procedural success.


EP Europace ◽  
2020 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
A P Martin ◽  
M Fowler ◽  
N Lever

Abstract Background Pulmonary vein isolation using cryotherapy is an established treatment for the management of patients with paroxysmal atrial fibrillation. Ablation using the commercially available balloon cryocatheter has been shown to create wide antral pulmonary vein isolation. A novel balloon cryocatheter (BCC) has been designed to maintain uniform pressure and size during ablation, potentially improving contact with the antral anatomy. The extent of ablation created using the novel BCC has not previously been established. Purpose To determine the anatomical extent of pulmonary vein isolation using electroanatomical mapping when performing catheter ablation for paroxysmal atrial fibrillation using the novel BCC. Methods Nine consecutive patients underwent pre-procedure computed tomography angiography of the left atrium to quantify the chamber dimensions. An electroanatomical map was created using the cryoablation system mapping catheter and a high definition mapping system. A bipolar voltage map was obtained following ablation to determine the extent of pulmonary vein isolation ablation. A volumetric technique was used to quantify the extent of vein and posterior wall electrical isolation in addition to traditional techniques for proving entrance and exit block. Results All patients had paroxysmal atrial fibrillation, mean age 56 years, 7 (78%) male. Electrical isolation was achieved for 100% of the pulmonary veins; mean total procedure time was 109 min (+/- 26 SD), and fluoroscopy time 14.9 min (+/- 2.4 SD). The median treatment applications per vein was one (range one - four), and median treatment duration 180 sec (range 180 -240). Left atrial volume 32 mL/m2 (+/- 7 SD), and mean left atrial posterior wall area 22 cm2 (+/- 4 SD). Data was available for quantitative assessment of the extent of ablation for eight patients. No lesions (0 of 32) were ostial in nature. The antral surface area of ablation was not statistically different between the left and right sided pulmonary veins (p 0.63), which were 5.9 (1.6 SD) and 5.4 (2.1 SD) cm2 respectively. In total 50% of the posterior left atrial wall was ablated.  Conclusion Pulmonary vein isolation using a novel BCC provides a wide and antral lesion set. There is significant debulking of the posterior wall of the left atrium. Abstract Figure.


PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1579 ◽  
Author(s):  
Wiesława Klimek-Piotrowska ◽  
Mateusz K. Hołda ◽  
Katarzyna Piątek ◽  
Mateusz Koziej ◽  
Jakub Hołda

Background.It is well known that the pulmonary veins (PVs), especially their myocardial sleeves play a critical role in the initiation and maintenance of atrial fibrillation. Understanding the PV anatomy is crucial for the safety and efficacy of all procedures performed on PVs. The aim of this study was to present normal distal PV anatomy and to create a juxtaposition of all PV ostium variants.Methods.A total of 130 randomly selected autopsied adult human hearts (Caucasian) were examined. The number of PVs ostia was evaluated and their diameter was measured. The ostium-to-last-tributary distance and macroscopic presence of myocardial sleeves were also evaluated.Results.Five hundred forty-one PV ostia were identified. Four classical PV ostia patterns (two left and two right PVs) were observed in 70.8% of all cases. The most common variant was the classical pattern with additional middle right PV (19.2%), followed by the common ostium for the left superior and the inferior PVs (4.44%). Mean diameters of PV ostia (for the classical pattern) were: left superior = 13.8 ± 2.9 mm; left inferior = 13.3 ± 3.4 mm; right superior = 14.3 ± 2.9 mm; right inferior = 13.7 ± 3.3 mm. When present, the additional middle right PV ostium had the smallest PV ostium diameter in the heart (8.2 ± 4.1 mm). The mean ostium-to-last-tributary (closest to the atrium) distances were: left superior = 15.1 ± 4.6 mm; left inferior = 13.5 ± 4.0 mm; right superior = 11.8 ± 4.0 mm; right inferior = 11.0 ± 3.7 mm. There were no statistically significant differences between sexes in ostia diameters and ostium-to-last-tributary distances.Conclusion.Only 71% of the cases have four standard pulmonary veins. The middle right pulmonary vein is present in almost 20% of patients. Presented data can provide useful information for the clinicians during interventional procedures or radiologic examinations of PVs.


Author(s):  
Filip Casselman ◽  
Ihsan Bakir ◽  
Pedro Brugada ◽  
Peter Geelen ◽  
Francis Wellens ◽  
...  

Objective To evaluate the feasibility and results of isolated endoscopic pulmonary vein isolation for paroxysmal atrial fibrillation using robotics. Methods Between November 2004 and December 2005, 13 patients (38.5% female) underwent robotic pulmonary vein isolation at our institution. Mean age was 46.8 ± 8.4 years and mean preoperative duration of atrial fibrillation was 52.7 ±31.5 months. Indication for surgery was symptomatic drug-refractory paroxysmal atrial fibrillation or recurrence after percutaneous treatment (n = 3). Mean preoperative left atrial dimension was 38.5 ± 6.9 mm. The surgical procedure was performed off-pump as an isolated right chest approach. All procedures were performed using the Flex 10 microwave ablator (Guidant, Indianapolis, IN), which was positioned from the right side through the transverse sinus and around the 4 pulmonary veins. Postoperative drug regimen included sotalol and Coumadin. Mean follow-up was 8.5 ± 3.4 months. Results The procedure was successful in 11 patients. One patient needed conversion to median sternotomy for right pulmonary artery bleeding and a second patient had severe transverse sinus adhesions requiring conversion to a bilateral video-assisted small thoracotomy approach. No other morbidity occurred. Mean procedure time in successful cases was 2.7 ± 0.8 hours (range 1.7 to 4 hours). Permanent sinus rhythm was successfully restored in 10 of 13 patients (76.9% beyond 6 months). Nonsuccessful patients had markedly reduced symptoms and frequency of events. One patient required a left and another a right atrial flutter ablation during follow-up. Conclusions Robotic pulmonary vein isolation is a feasible procedure that has the potential to become a valid option in the treatment of paroxysmal atrial fibrillation.


Circulation ◽  
2000 ◽  
Vol 101 (11) ◽  
pp. 1274-1281 ◽  
Author(s):  
Wei-Shiang Lin ◽  
V. S. Prakash ◽  
Ching-Tai Tai ◽  
Ming-Hsiung Hsieh ◽  
Chin-Feng Tsai ◽  
...  

2020 ◽  
Vol 33 (2) ◽  
pp. 106-114
Author(s):  
Michele Brunelli ◽  
Mark Adrian Sammut

Catheter ablation of long-standing persistent atrial fibrillation is not yet clearly defined with respect to endpoints, and different ablative strategies are offered to patients. Presented here is an approach aiming at biatrial debulking in the form of extensive linear ablation, specifically targeting areas of low-voltage complex fractionated electrograms, in addition to pulmonary vein isolation. Its main advantage is that it is not dependent on operator/system variability, since the strategy of isolating the pulmonary veins, superior vena cava and left atrial posterior wall together with achievement of bidirectional block during linear ablation provides objective endpoints that can consistently be reproduced.


Author(s):  
Sapan Bhuta ◽  
Gustaf Sverin ◽  
Hiro Kawata ◽  
Malek Bashti ◽  
Jessica Hunter ◽  
...  

Background: Previous studies suggest that wide area circumferential pulmonary vein ablation (WACA) is more effective than segmental pulmonary vein ablation (SPVA) for pulmonary vein isolation (PVI) for treatment of atrial fibrillation. Whether this is true in patients (pts) with very short duration paroxysmal atrial fibrillation (PAF) is unknown. Objective: To compare WACA to SPVA in pts with PAF lasting <48 hours. Methods: One hundred pts with PAF <48 hours were randomized to either WACA vs SPVA (45 and 53 pts respectively, with 2 withdrawals), and followed up for 24 months with 14-day ECGs every 6 months. Results: Among 97 pts at an average of 22.1±4.8 months followup, 26 (57.8%) remained free of any atrial arrhythmias after WACA versus 29 (55.86%) after SPVA (p=0.64). Sixteen pts (35.6%) had recurrent PAF after WACA versus 20 pts (38.5%) after SPVA (p=0.79). Seven pts (15.6%) had atrial flutter after WACA versus 5 pts (9.64%) after SPVA (p=0.376) and 1 pt (2.2%) had atrial tachycardia after WACA vs 1 pt (1.9%) after SPVA (p=0.918). Total procedure time was lower for SPVA vs WACA (242.9 vs 271.1 minutes, p= 0.047), and fluoroscopy time similar for WACA vs SPVA (50.8 vs 53.4 minutes, p=0.555). Conclusions: As an initial ablation approach in pts with PAF <48 hours, SPVA was similarly effective to WACA with respect to arrhythmia recurrence, supporting the central role of the pulmonary veins for maintaining AF in these pts. Future therapies using alternative ablation energies may incorporate these insights to reduce risk to gastroesophageal structures.


EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
C Martignani ◽  
M Ziacchi ◽  
G Statuto ◽  
A Spadotto ◽  
A Angeletti ◽  
...  

Abstract Funding Acknowledgements Type of funding sources: None. Background Electric isolation of the pulmonary veins (PVs) can successfully treat patients with atrial fibrillation (AF). Isolation of pulmonary veins can be achieved by several methods: radiofrequency, cryoballoon or laser balloon ablation (LBA). The main procedural challenge with either method is to achieve a continuous circumferential lesion at the left atrium-PVs junction, with the persistence of functional gaps. Purpose A novel endoscopic ablation system equipped with a precise motor control system (MCS) has been evaluated. The balloon is used with an endoscope to directly visualize and ablate tissue at the left atrial-PVs junction with laser energy. This system enables uninterrupted, high-speed, circumferential lesion creation under direct control of the physician. The MCS is intended to reduce procedure time and to ensure continuity of ablation lesions. The feasibility of the motorized ablation in terms of extent of applicability along each PV-left atrium junction and time of use of the manual point-by-point mode has been investigated. Methods sixteen consecutive patients (male 68.7%, age 60.9 ± 7.8 years) with paroxysmal or persistent AF who underwent LBA were enrolled in our institution. Exclusion criteria were any contraindication for the procedure including the presence of intracavitary thrombosis and contraindications to general anesthesia or deep sedation. After transseptal puncture, the balloon-based endoscopic ablation system was advanced to each PV ostium, and laser energy were projected onto the target. Results A total of 62 PVs were treated with LBA; in 3 patients there was a redundant right intermediate pulmonary vein; in 4 patients there was a right common ostium and in one a left common ostium. MCS was used for 41 PVs (66.1%): in particular, MCS was used continuously between 180° and 325° degrees (50 to 90% of PV circumference) for 22 PVs (35.5%) and between 326° and 359° degrees (91 to 99% of PV circumference) for 16 veins (25.8%).  In 3 PVs (4.8%) MCS was used for the entire circumference.  During 5.659 (23.6%) seconds out of a total of 23.986 seconds, laser energy delivery occurred in the rapid mode by MCS. No clinical complications, either local or systemic (stroke or TIA, pericardial effusion, pericardial  tamponade, pulmonary vein stenosis, esophageal injury, temporary or permanent phrenic nerve palsy), were observed neither during the use of MSC nor during the use of manual point-by-point mode. Of note, a pinhole rupture of the balloon occurred in the first 2 cases of our series, during the use of MCS, without harm to the patient and requiring only replacement of the LBA. Conclusions In our case series, laser balloon ablation with the help of motor control system appears safe and feasible in most cases for large portions of pulmonary vein circumference, providing considerable time sparing (66.1% of total ablation extent in 23.6% of total ablation time).


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