Study of the Characteristics of the Pulmonary Vein and Superior Vena Cava of Rabbits

Background: This study aims to (1) investigate the characteristics of the action potential and triggering activity of cardiomyocytes in the pulmonary vein (PV) and superior vena cava (SVC) of rabbits and (2) study the features of cation currents in cardiomyocytes in rabbit PV and SVC-inward rectifier potassium current (IK1), transient outward potassium current (Ito), and non-selective cation currents (INSCC). Methods: The standard glass microelectrode and whole-cell patch-clamp techniques were used to record the action potential and various currents in the above cells. Results: (1) Cardiomyocytes in either PV or SVC had longer action potential durations than in the adjacent atrium, and spontaneous early after depolarization (EAD) could occur in both PV and SVC under normal physiological conditions. (2) The action potential in PV cardiomyocytes had a relative refractory period but did not have an absolute refractory period, and this characteristic enabled a premature beat that triggered a second plateau response, which led to EAD. (3) INSCC was found for the first time in the PV, SVC, and atria. (4) The current intensity of IK1, Ito, and INSCC was significantly lower in the PV and SVC than in the left and right atria, and the difference in the current intensity in INSCC could influence the action potential. Conclusions: PV and SVC can both initiate and maintain AF, but PV is the primary ectopic foci in initiating AF. The present study found that the second plateau response was easily induced in cardiomyocytes in PA shortly after depolarization. This was a specific characteristic of the action potential of PV. In addition, we preliminarily analyzed the differences in the main outward currents and noted a voltage-dependent INSCC in both PV and SVC rabbits’ cardiomyocytes. Furthermore, the current intensities of IK1, Ito, and INSCC were significantly lower in the PV and SVC than in the left and right atria, and the difference in the current intensity of INSCC influenced the action potential. The different permeability of INSCC for cations at different phases may play a role in inducing EAD.

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Relationship between effective refractory period and inducibility of atrial fibrillation from the superior vena cava after pulmonary vein isolation

10.22541/au.163258183.33210039/v1 ◽

2021 ◽

Author(s):

Yasunobu Yamagishi ◽

Yasushi Oginosawa ◽

Yoshihisa Fujino ◽

Keishiro Yagyu ◽

Taro Miyamoto ◽

...

Keyword(s):

Atrial Fibrillation ◽

Pulmonary Vein ◽

Superior Vena Cava ◽

Pulmonary Vein Isolation ◽

Refractory Period ◽

Superior Vena ◽

Three Dimensional ◽

Vena Cava ◽

Effective Refractory Period ◽

Electrical Stimuli

Background: In terms of the pulmonary vein (PV), atrial fibrillation (AF) patients have a shorter effective refractory period (ERP) and a larger dispersion of the ERP than patients without AF. Although the frequency of AF from the superior vena cava (SVC) was the highest among non-PV foci, the characteristics of the ERP in the SVC (SVC-ERP) were unclear. The purpose of this study was to elucidate the relationship between SVC-ERP and the inducibility of AF after pulmonary vein isolation (PVI). Methods and Results: Consecutive 28 patients who underwent PVI were included. After successful PVI, the SVC-ERP was measured at three positions in SVC. Rapid electrical stimuli were delivered at the shortest SVC-ERP to induce AF. Patients in whom AF was induced were assigned to the SVC-induced group (SIG) and the remaining patients were the non-SVC-induced group (non-SIG). The size of the SVC sleeve was evaluated using three-dimensional electroanatomic mapping. The SIG had a significantly shorter average SVC-ERP (236.0±25.2 vs. 294.8±36.8 ms, p<0.001), while SVC-ERP dispersion was not significantly different (30.0±25.4 vs. 33.3±20.1 ms, p=0.56). Although the longer SVC diameter was significantly longer in the SIG (27.4±4.3 vs. 22.9±4.6 mm, p=0.03), the SVC-ERP was significantly associated with pacing inducibility of AF after adjustment for the longer SVC diameter (odds ratio: 0.96 [1-ms increments], p=0.01). Conclusions: The SIG had a shorter SVC-ERP, while the dispersion was not significantly different between the two groups. The SVC-ERP can be one of the mechanisms of arrhythmogenicity for AF originating from the SVC.

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Coughing as a potentially effective induction method of atrial tachycardia: a case report

European Heart Journal - Case Reports ◽

10.1093/ehjcr/ytaa459 ◽

2020 ◽

Author(s):

Reina Tonegawa-Kuji ◽

Kenichiro Yamagata ◽

Kengo Kusano

Keyword(s):

Pulmonary Vein ◽

Atrial Tachycardia ◽

Superior Vena ◽

Vena Cava ◽

P Wave ◽

Induction Method ◽

Voluntary Cough ◽

Wave Morphology ◽

The Right

Abstract Background Cough-induced atrial tachycardia (AT) is extremely rare and its electrical origin remains largely unknown. Atrial tachycardias triggered by pharyngeal stimulation, such as swallowing or speech, appears to be more common and the majority of them originate from the superior vena cava or right superior pulmonary vein (PV). Only one case of swallow-triggered AT with right inferior pulmonary vein (RIPV) origin has been reported to date. Case summary We present a case of a 41-year-old man with recurring episodes of AT in the daytime. He underwent electrophysiology study without sedation. Atrial tachycardia was not observed when the patient entered the examination room and could not be induced with conventional induction procedures. By having the patient cough periodically on purpose, transient AT with P-wave morphology similar to the clinical AT was consistently induced. Activation mapping of the AT revealed a centrifugal pattern with the earliest activity localized inside the RIPV. After successful radiofrequency isolation of the right PV, AT was no longer inducible. Discussion In the rare case of cough-induced AT originating from the RIPV, the proximity of the inferior right ganglionated plexi (GP) suggests the role of GP in triggering tachycardia. This is the first report that demonstrates voluntary cough was used to induce AT. In such cases that induction of AT is difficult using conventional methods, having the patient cough may be an effective induction method that is easy to attempt.

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Multicenter study of novel mapping technique to detect non-pulmonary vein triggers excluding the origin from left atrial posterior wall and superior vena cava

European Heart Journal ◽

10.1093/ehjci/ehaa946.0564 ◽

2020 ◽

Vol 41 (Supplement_2) ◽

Author(s):

Y Matsunaga ◽

Y Egami ◽

M Yano ◽

M Yamato ◽

R Shutta ◽

...

Keyword(s):

Pulmonary Vein ◽

Superior Vena Cava ◽

Left Atrial ◽

Medical Center ◽

Superior Vena ◽

Vena Cava ◽

Posterior Wall ◽

Mapping Technique ◽

Left Atrial Posterior ◽

Self Reference

Abstract Background It has been reported that elimination of non-pulmonary vein (PV) triggers after PV isolation is a good predictor of atrial tachyarrhythmia free survival. However, precise mapping of triggers outside from superior vena cava (SVC) or left atrial posterior wall (LAPW) are difficult. The aim of this study is to assess the efficacy of self-reference mapping technique to eliminate non-PV triggers originated from outside of primordial pulmonary vein area. Methods Total of 431 patients (446 procedures) underwent atrial fibrillation (AF) ablation in a hospital and in a medical center from January 2017 to March 2019. After isolation of PV, non-PV triggers were induced with isoproterenol and/or adenosine triphosphate. Reproducible non-PV triggers were targeted to ablate using following self-reference mapping technique: A trigger conducts centrifugally and the earliest site should be distinguished from other later activated sites. Using a PentaRay multipolar catheter, the operators annotated the earliest site of local activation and a reference tag was placed. The multipolar catheter was then moved to the reference tag and the process repeated. Ultimately, we identified clusters of early circumferential activation and ablated. Results A total of 32 non-PV triggers excluding the origin from LAPW and SVC were induced in 23 patients. Nineteen triggers (59%) were located in the right atrium and 13 triggers (41%) in the left atrium (Figure 1). All triggers were eliminated with ablation and AF was non-inducible in all patients at the end of the procedure. During the follow-up (529±270 days), 18 patients (77%) were free from atrial tachyarrhythmias after a 3-month blanking period. Three patients received additional ablation procedures for recurrent atrial arrhythmias. No non-PV triggers ablated during the previous procedure were observed. Conclusion A novel self-reference mapping technique is useful for eliminating non-PV triggers in terms of the short- and long-term success. Figure 1. Distribution of non-PV triggers Funding Acknowledgement Type of funding source: None

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Development of Superior Vena Cava to Pulmonary Vein Fistulae Following Modified Fontan Operation: Case Report of a Rare Anomaly and Embolization Therapy

Pediatric Cardiology ◽

10.1007/s002469900325 ◽

1998 ◽

Vol 19 (4) ◽

pp. 363-365 ◽

Cited By ~ 11

Author(s):

S. Clapp ◽

W.R. Morrow

Keyword(s):

Case Report ◽

Pulmonary Vein ◽

Superior Vena Cava ◽

Superior Vena ◽

Fontan Operation ◽

Vena Cava ◽

Embolization Therapy ◽

Rare Anomaly ◽

Modified Fontan Operation ◽

Operation Case

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176-23: Ectopies from the superior vena cava after pulmonary vein isolation in patients with atrial fibrillation

EP Europace ◽

10.1093/europace/18.suppl_1.i123 ◽

2016 ◽

Vol 18 (suppl_1) ◽

pp. i123-i123

Author(s):

Sousuke Sugimura

Keyword(s):

Atrial Fibrillation ◽

Pulmonary Vein ◽

Superior Vena Cava ◽

Pulmonary Vein Isolation ◽

Superior Vena ◽

Vena Cava

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Unilateral Pulmonary Vein Atresia with Absent Right Superior Vena Cava

Korean Circulation Journal ◽

10.4070/kcj.1991.21.3.606 ◽

1991 ◽

Vol 21 (3) ◽

pp. 606

Author(s):

Hyoung Doo Lee ◽

Chung Il Noh ◽

Jung Yun Choi ◽

Yong Soo Yun

Keyword(s):

Pulmonary Vein ◽

Superior Vena Cava ◽

Superior Vena ◽

Vena Cava

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Single sweep pulmonary vein isolation using the endoscopic ablation system. Dream or reality?

EP Europace ◽

10.1093/europace/euab116.066 ◽

2021 ◽

Vol 23 (Supplement_3) ◽

Author(s):

B Schmidt ◽

S Tohoku ◽

S Bordignon ◽

S Chen ◽

S Zanchi ◽

...

Keyword(s):

Pulmonary Vein ◽

Pulmonary Vein Isolation ◽

Superior Vena ◽

Safety Data ◽

Vena Cava ◽

Private Company ◽

Endoscopic Ablation ◽

First Pass ◽

Diagnostic Catheter

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): CardioFocus Background The endoscopic ablation system (EAS) is an established ablation device for pulmonary vein isolation (PVI) in patients with paroxysmal and persistent atrial fibrillation (AF). In randomized studies, however, point-by-point laser ablation resulted in longer procedure times. The novel X3 EAS is now equipped with a motor driven laser generator that sweeps the diode laser beam around the individual PV ostium at a pre-defined speed (2.25°/sec) thus allowing for contiguous circumferential ablation (RAPID mode). Purpose To determine the feasibility of single sweep ablation using the new X3 EAS. Methods Consecutive AF patients were enrolled. After single transseptal puncture selective PV angiographies were performed. A 3D enabled circular mapping catheter was used to record PV potentials and to create a 3D map of the left atrium. Then, the transseptal sheath was exchanged for the 12F EAS delivery sheath. The EAS was inflated to obtain optimal circumferential contact to the PV ostium. Before ablation, the laser generator was retracted to ensure optimal contact behind the catheter shaft (blind spot). Ideally, RAPID mode ablation was employed at 13-15W. In case of esophageal heating >39°C or suboptimal tissue exposure point-by-point ablation (5.5-12W for 20-30 secs) was used instead. During ablation at the septal PVs phrenic nerve pacing was performed via a diagnostic catheter in the superior vena cava. Single sweep ablation was defined as one single RAPID energy application per PV to complete the singular, circular lesion set. PV conduction was re-assessed after all PVs had been treated. In case of residual PV conduction, gap mapping followed by EAS guided ablation was performed. If EAS failed to achieve complete PVI, touch up ablation was allowed at the discretion of the operator. Hemostasis was achieved by means of a figure of 8 suture. Procedure time was defined as initial groin puncture to groin closure. Follow-up included office visits at 3, 6 and 12 months including 72 h Holter monitoring. Results One-hundred AF patients (56% male, mean age 6810 years, 66% PAF) with normal LV ejection fraction (mean 60 ± 10%) and normal LA size (41 ± 6mm) underwent X3 EAS ablation. Of 382 PVs 378 (99%) were isolated with the X3 EAS. In 214 PVs (56%) single sweep isolation was achieved. First pass isolation and RAPID mode only PVI was achieved in 362 (95%) and 357 (94%), respectively. Single sweep isolation rates varied across PVs from 46% at LIPV to 64% at RSPV. The mean total procedure and fluoroscopy times were 43 ± 10 and 4 ± 2 mins, respectively. Safety data and the complete follow-up will be reported. Conclusion The new X3 EAS equipped with a motor driven laser generator allows for single sweep PVI in 56% of PVs. Almost all PVs (94%) may be isolated with RAPID mode only leading to a very high first pass isolation rate. Altogether, this leads to substantially faster procedure times compared to the predecessor EAS.

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Outcomes of surgical reconstruction of the superior vena cava syndrome in patients with locally advanced thymomas

EUREKA Health Sciences ◽

10.21303/2504-5679.2021.001852 ◽

2021 ◽

pp. 37-44

Author(s):

Valeriy Boyko ◽

Andriy Krasnoyaruzhskyi ◽

Dmytro Minukhin ◽

Dmytro Dubovyk ◽

Kateryna Ponomarova ◽

...

Keyword(s):

Relative Risk ◽

Superior Vena Cava ◽

Superior Vena ◽

Locally Advanced ◽

Vena Cava ◽

Control Group ◽

Lethal Outcome ◽

Vena Cava Syndrome ◽

Left And Right ◽

Experimental Group

The aim of the study: to study and demonstrate the potential and technical aspects of the surgical treatment of locally advanced thymus tumours with the tumour infiltrate affecting superior vena cava and its branches. Methods. 56 patients with locally advanced thymomas complicated by SVCS were study. The control group included 30 patients with SVCS were treated with conventional techniques, while the experimental group included 26 patients who underwent a novel bypass surgery developed by us. Results. Based on our observations, patients tolerated these surgeries much better. The venous bypass was mandatorily complemented with cytoreduction. Auriculo-jugular (left and right) and auriculo-subclavian (left and right) bypasses were used in our observations Complications in the post-operative period were reported from the experimental group and included auriculo-subclavian bypass thrombosis, post-operative complications were reported in the control group including haemorrhage from the sternotomy wound in 1 (3.3 %) case, superior vena cava thrombosis in 2 (6.6 %) cases, pneumonia in 2 (6.6 %) cases and thromboembolism of small pulmonary arteries in 2 (6.6 %) cases. Post-operative lethality in the study groups was reported in the control and in the experimental group. Total lethality rate was 8.9 % (5 patients). The relative risk of complications and lethal outcome was calculated for patients from both groups. It was found that the risk of complications was twice as high in the control group as in the experimental group (standard error of relative risk equals 0.64), whereas the risk of lethal outcome increased by a factor of 3.5 in the control group (standard error of relative risk equals 1.09) Conclusion. It has been established that the superior vena cava syndrome in patients with locally advanced thymoma is an emergency condition whose surgical correction must be personalised depending on the anatomic and topographic classification of SVC lesion types. It is known that an obligatory pre-condition of the perioperative period in this category of patients is an adequate vascular approach to the superior vena cava system. The first mandatory step of the radical surgery in patients with locally advanced thymomas with SVC invasion should be the auriculo-jugular and auriculo-subclavian bypasses, which can reduce the relative risk of post-operative complications by a factor of the risk of lethal by a factor of 3.5.

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