Refractoriness of the Sheep Superior Vena Cava Myocardial Sleeve

2008 ◽  
Vol 233 (11) ◽  
pp. 1441-1447 ◽  
Author(s):  
Cuimei Zhao ◽  
Jie Qi ◽  
Xingyuan Liu ◽  
Huaizhi Chen ◽  
Jun Li ◽  
...  
Keyword(s):  
Superior Vena Cava ◽  
Superior Vena ◽  
Vena Cava ◽  
Ionic Current ◽  
Right Atrial ◽  
Parasympathetic Nerve ◽  
Right Atrial Appendage ◽  
The Right ◽  
Type 3

The cardiomyocytes in the superior vena cava (SVC) myocardial sleeve have distinct action potentials and ionic current profiles, but the refractoriness of these cells has not been reported. Using standard intracellular microelectrode techniques, we demonstrated in sheep that the effective refractory period (ERP) of the cardiomyocytes in the SVC (114.7 ± 6.5 ms) is shorter than that in the inferior vena cava (IVC) (166.7 ± 6.2 ms), right atrial free wall (RAFW) (201.0 ± 6.0 ms) and right atrial appendage (RAA) (203.1 ± 5.8 ms) ( P < 0.05). The right atrial cardiomyocyte ERP was heterogeneously shortened by acetylcholine, a muscarinic type 2 receptor (M2R) agonist. After perfusion with 15 μM acetylcholine, the shortest ERP occurred in the SVC (the ERP in the SVC, IVC, RAFW and RAA was 53.6 ± 2.7, 98.9 ± 2.2, 121.8 ± 6.0 and 109.7 ± 5.1 ms, respectively; P < 0.05). Carbachol (1 μM), another M2R agonist, produced a similar effect as acetylcholine. Furthermore, we used methoctramine, a M2R blocker, 4-DAMP, a muscarinic type 3 receptor (M3R) blocker, and tropicamide, a muscarinic type 4 receptor (M4R) blocker to inhibit the acetylcholine-induced ERP shortening of SVC cardiomyocytes, and found that the 50% inhibitory concentration for methoctramine, 4-DAMP and tropicamide was 5.91, 45.72 and 80.34 nM, respectively. Therefore, we conclude that the sheep SVC myocardial sleeve is a unique electrophysiological region of the right atrium with the shortest ERP both under physiological condition and under cholinergic agonist stimulation. M2R might play a major role in the response of the SVC myocardial sleeve to parasympathetic nerve tone. The association between the distinct refractoriness in SVC and atrial fibrillation originating from the region deserves further investigation.

scholarly journals Extremely late asymptomatic atrial lead dislodgement from the right atrial appendage to superior vena cava with autopsy findings

2020 ◽  
Vol 6 (10) ◽  
pp. 741-744
Author(s):  
Rena Nakamura ◽  
Yasuteru Yamauchi ◽  
Kaoru Okishige ◽  
Jiro Kumagai ◽  
Masahiko Goya ◽  
...  
Keyword(s):  
Superior Vena Cava ◽  
Superior Vena ◽  
Vena Cava ◽  
Atrial Appendage ◽  
Right Atrial ◽  
Autopsy Findings ◽  
Right Atrial Appendage ◽  
The Right ◽  
Lead Dislodgement

scholarly journals Recurrent cardiac hydatid cyst located near the root of the superior vena cava and the interatrial septum: a case report

2022 ◽  
pp. 1-4
Author(s):  
Redha Lakehal ◽  
Farid Aymer ◽  
Soumaya Bendjaballah ◽  
Rabah Daoud ◽  
Khaled Khacha ◽  
...  
Keyword(s):  
Hydatid Cyst ◽  
Facial Paralysis ◽  
Superior Vena Cava ◽  
Superior Vena ◽  
Vena Cava ◽  
Lower Lobe ◽  
Lateral Wall ◽  
Right Atrial ◽  
Risk Of Rupture ◽  
The Right

Introduction: Cardiac localization of hydatid disease is rare (<3%) even in endemic countries. Affection characterized by a long functional tolerance and a large clinical and paraclinical polymorphism. Serious cardiac hydatitosis because of the risk of rupture requiring urgent surgery. The diagnosis is based on serology and echocardiography. The aim of this work is to show a case of recurrent cardiac hydatid cyst discovered incidentally during a facial paralysis assessment. Methods: We report the observation of a 26-year-old woman operated on in 2012 for pericardial hydatid cyst presenting a cardiac hydatid cyst located near the abutment of the SCV discovered incidentally during an exploration for left facial paralysis: NYHA stage II dyspnea. Chest x-ray: CTI at 0.48. ECG: RSR. Echocardiography: Image of cystic appearance at the level of the abutment of the SVC. SAPP: 38 mmhg, EF: 65%. Thoracic scan: 30/27 mm cardiac hydatid cyst bulging the lateral wall of the right atrium and the trunk of the right pulmonary artery with fissured cardiac hydatid cyst of the apical segment of the right lung of the right lower lobe with multiple bilateral intra parenchymal and sub pleural nodules. The patient was operated on under CPB. Intraoperative exploration: Presence of a hard and whitish mass, about 03 / 03cm developed in the full right atrial wall opposite the entrance to the superior vena cava. Procedure: Resection of the mass removing the roof of the LA, the AIS and the wall of the RA with reconstruction of the roof of the RA by patch in Dacron and reconstruction of the IAS and the wall of the RA by a single patch in Dacron. Results: The postoperative suites were simple. Conclusion: The hydatid cyst is still a real endemic in Algeria, the cardiac location is rare but serious and can constitute a real surgical emergency, hence the importance of prevention. Keywords: Hydatid cyst of the heart; Recurrence; Surgery; Cardiopulmonary Bypass; Prevention

scholarly journals A case of blunt injury to the superior vena cava and right atrial appendage: Mechanisms of injury and review of the literature

Injury Extra ◽  
2005 ◽  
Vol 36 (8) ◽  
pp. 341-345 ◽  
Author(s):  
Rabih A. Chaer ◽  
James C. Doherty ◽  
Gary Merlotti ◽  
Steven L. Salzman ◽  
Don Fishman
Keyword(s):  
Superior Vena Cava ◽  
Superior Vena ◽  
Vena Cava ◽  
Atrial Appendage ◽  
Right Atrial ◽  
Blunt Injury ◽  
Review Of The Literature ◽  
Right Atrial Appendage

scholarly journals Right-Sided Permanent Pacemaker Implantation in Patients with Persistent Left Superior Vena Cava with Absent Right Superior Vena Cava: 3-Case Series, Technique and Discussion

2021 ◽  
pp. 1-4
Author(s):  
Calin Siliste ◽  
Maria-Claudia-Berenice Suran ◽  
Calin Siliste ◽  
Andreea-Elena Velcea ◽  
Sebastian Stoica ◽  
...  
Keyword(s):  
Superior Vena Cava ◽  
Superior Vena ◽  
Vena Cava ◽  
Case Series ◽  
Right Atrial ◽  
Left Superior Vena Cava ◽  
Persistent Left Superior Vena ◽  
Ventricular Lead ◽  
Tertiary Center ◽  
The Right

Persistent left superior vena cava (PLSVC) is the most common variant of abnormal venous return to the heart. While usually asymptomatic, it is known to complicate transvenous cardiac procedures, such as implantation of cardiac electronic devices and ablations. PLSVC can present with or without the concomitant absence of right superior vena cava (RSVC). Depending on the operator's preference, implantation of permanent cardiac pacemakers (PPMs) may be performed from the left or right side. As most often the PLSVC is only identified at the time of intervention, it follows that the variant with the absence of RSVC can be diagnosed in practice only when implanting from the right side. For this reason, the true prevalence of this variant is largely unknown because most published cases of cardiac device implantations in patients with PLSVC have been performed from the left side. We present a short 3-case series of PPM implantations in a tertiary center from the right side in patients with PLSVC and absent RSVC. We found that the use of a standard curve for ventricular lead septal placement and a wide C-curve for right atrial lead placement in these patients was a feasible technique with good outcomes.

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