Region-specific distribution of transversal-axial tubule system organization underlies heterogeneity of calcium dynamics in the right atrium

2021 ◽  
Author(s):  
Di Lang ◽  
Roman Y. Medvedev ◽  
Lucas Ratajczyk ◽  
Jingjing Zheng ◽  
Xiaoyu Yuan ◽  
...  
Keyword(s):  
Superior Vena ◽  
Vena Cava ◽  
Confocal Imaging ◽  
Right Atrial ◽  
Atrial Remodeling ◽  
Atrial Myocardium ◽  
Healthy Human ◽  
Crista Terminalis ◽  
Specific Distribution ◽  
The Right

The atrial myocardium demonstrates the highly heterogeneous organization of the transversal-axial tubule system (TATS), while its anatomical distribution and region-specific impact on Ca2+ dynamics remain unknown. We developed a novel method for high-resolution confocal imaging of TATS in intact live mouse atrial myocardium and applied a Matlab-based computational algorithm for the automated analysis of TATS integrity. We observed a 2-fold higher (P<0.01) TATS density in the right atrial appendage (RAA) than in the inter-caval region (ICR, the anatomical region between the superior vena cava and atrioventricular junction and between the crista terminalis and inter-atrial septum). While RAA predominantly consisted of well-tubulated myocytes, ICR showed partially tubulated/untubulated cells. Similar TATS distribution was also observed in healthy human atrial myocardium sections. In both mouse atrial preparations and isolated mouse atrial myocytes, we observed a strong anatomical correlation between TATS distribution and Ca2+ transient synchronization and rise-up time. This region-specific difference in Ca2+ transient morphology disappeared after formamide-induced detubulation. ICR myocytes showed a prolonged action potential duration at 80% of repolarization as well as a significantly lower expression of RyR2 and Cav1.2 proteins, but similar levels of NCX1 and Cav1.3 compared to RAA tissue. Our findings provide a detailed characterization of the region-specific distribution of TATS in mouse and human atrial myocardium highlighting the structural foundation for anatomical heterogeneity of Ca2+ dynamics and contractility in the atria. These results could indicate different roles of TATS in Ca2+ signaling at distinct anatomical regions of the atria and provide mechanistic insight into pathological atrial remodeling.

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 Intravenous Leiomyomatosis of the Uterus: A Retrospective Single-Center Study in 14 Cases

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Qingbo Su ◽  
Xiquan Zhang ◽  
Hui Zhang ◽  
Yan Liu ◽  
Zhaoru Dong ◽  
...  
Keyword(s):  
Right Atrium ◽  
Superior Vena ◽  
Vena Cava ◽  
Right Atrial ◽  
Pelvic Cavity ◽  
Intravenous Leiomyomatosis ◽  
Abdominal Incision ◽  
Imaging Results ◽  
The Right

Purpose. This study aimed to retrospectively review the diagnosis and surgical treatment of uterine intravenous leiomyomatosis (IVL). Methods. The clinical data of 14 patients with uterine IVL admitted to our hospital between 2013 and 2018 were retrospectively analyzed, including their demographics, imaging results, surgical procedures, perioperative complications, and follow-up results. Results. The tumors were confined to the pelvic cavity in 7 patients, 1 into the inferior vena cava, 4 into the right atrium, and 2 into the pulmonary artery (including 1 into the superior vena cava). Only one case was misdiagnosed as right atrial myxoma before the operation, which was found during the surgery and was treated by staging surgery; all the other patients underwent one-stage surgical resection. Three patients underwent complete resection of the right atrial tumor through the abdominal incision, and one patient died of heart failure in the process of resection of heart tumor without abdominal surgery. During the 6–60 months of follow-up, 4 patients developed deep venous thrombosis of the lower extremity, and 1 patient developed ovarian vein thrombosis and pulmonary embolism. After anticoagulation treatment, the symptoms disappeared. One patient refused hysterectomy and the uterine fibroids recurred 4 years after the operation. Conclusion. Specific surgical plans for uterine IVL can be formulated according to cardiac ultrasound and computed tomography (CT). For the first type of tumor involving the right atrium, the right atrium tumor can be completely removed through the abdominal incision alone to avoid thoracotomy. The disease is at high risk of thrombosis and perioperative routine anticoagulation is required.

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.

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 Coronary sinus atrial septal defects in adults over the past 20 years at new Tokyo hospital: case series

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Haruhiko Sugimori ◽  
Tatsuya Nakao ◽  
Yuki Ikegaya ◽  
Daisuke Iwahashi ◽  
Shoichi Tsuda ◽  
...  
Keyword(s):  
Coronary Sinus ◽  
Surgical Repair ◽  
Wide Spectrum ◽  
Superior Vena ◽  
Vena Cava ◽  
Case Series ◽  
Right Atrial ◽  
Valvular Regurgitation ◽  
Type Iv ◽  
The Right

Abstract Background An isolated coronary sinus (CS) atrial septal defect (ASD) is defined as a CS unroofed in the terminal portion without a persistent left superior vena cava or other anomalies. This defect is rare and part of the wide spectrum of unroofed CS syndrome (URCS). Recently, several reports have described this finding. The database of New Tokyo Hospital was searched to determine the incidence of this defect. Additionally, to raise awareness of this condition, the findings from five patients with CS ASD who underwent surgical repair at New Tokyo Hospital are discussed. Case presentation The patients were three women and two men with an age range of 63–77 years. All patients underwent transthoracic echocardiography and computed tomography, and one underwent magnetic resonance imaging. In two patients, the defect was found unexpectedly intraoperatively; left-to-right shunting was apparent in the other three patients preoperatively. The pulmonary-to-systemic blood flow ratio ranged from 1.42 to 3.1 following cardiac catheterization, and oxygen saturation step-up was seen on the right side of the heart. Valvular regurgitation was seen in 4/5 patients with different combinations and degrees of mitral, tricuspid, and aortic valve involvement. Right atrial and ventricular dilation were seen in 4/5 patients; three patients had left atrial dilation. Three patients experienced atrial fibrillation, and one of these also experienced paroxysmal ventricular contractions. All patients underwent surgical repair, and some underwent multiple procedures. One patient who had previously undergone kidney transplantation died approximately 1 year postoperatively; the remaining four patients are currently experiencing good activities of daily living without symptoms. Conclusions CS ASD (Kirklin and Barratt–Boyes type IV URCS) comprised 1.3% of adult congenital heart surgeries and 0.07% of adult open-heart surgeries at New Tokyo Hospital from 1999 to 2019. At New Tokyo Hospital, cardiac surgery is performed mainly for patients with acquired cardiac disease, and CS ASD is rare. Early diagnosis is important, as well as early surgical repair in symptomatic patients, especially those with blood access shunts, which may overload the heart. The case of a poor prognosis in this series is noteworthy, as similar cases have not been reported previously.

Right Atrial Surgery without Caval Snaring

2005 ◽  
Vol 1 (2) ◽  
pp. 75-78 ◽  
Author(s):  
Reddy Dandolu ◽  
Douglas Eaton ◽  
Aras Ali ◽  
Nannette Schwann ◽  
Andrew Wechsler
Keyword(s):  
Animal Model ◽  
Right Atrium ◽  
Inferior Vena ◽  
Superior Vena ◽  
Vena Cava ◽  
Drainage System ◽  
Mitral Valve Surgery ◽  
Right Atrial ◽  
Percutaneous Cannulation ◽  
The Right

Background During tricuspid valve replacement in a patient with previous mitral valve surgery, we made an incidental observation that the right atrium can be opened without caval snaring and without air entering the venous reservoir. We tested this hypothesis on an animal model. Methods Two patients underwent right atrial surgery using percutaneous cannulation, and no air was entrained without caval snaring. This principle was tested in an animal model using 2 pigs weighing 80 kg each. Percutaneous cannulae were placed under epicardial echo guidance with their tips 4 cm from the right atrium. A “collapsible bag with air drainage system” was introduced into the venous return system to quantify air return from the superior vena cava (SVC) and inferior vena cava (IVC). Two types of percutaneous cannulae with (Cardiovations Quick Draw) and without (Biomedicus) proximal side holes were tested. Results In the animal model using Biomedicus cannulae, upon opening the right atrium, air was entrained from the SVC cannula at 60 mL/minute with no air in the IVC. There was no difference in the amount of air between the two cannulae. Pressures measured were 5 cm of water in the IVC and −20 cm water in the SVC. Epicardial ultrasound demonstrated complete collapse of both vena cavae. Partial clamping of the SVC cannula reduced the amount of air to 60 cc/min, and placing a small straight clamp at the SVC atrial junction eliminated the air. No air was noted in IVC cannula. Conclusions Inferior vena caval drainage by percutaneous cannula does not entrain air with either type of cannula and without snaring (both in clinical cases and animal model). This might be explained by the presence of a competent Eustachian valve. However, the SVC is not immune to air. Minimal air (approximately 60 mL/minute) could be managed by partial clamping or completely be avoided by placing a small straight clamp without snaring.

Atresia of the right atrial ostium of the coronary sinus without persistent left superior vena cava

2015 ◽  
Vol 9 (3) ◽  
pp. 227-229
Author(s):  
Nobuo Tomizawa ◽  
Masamichi Takahashi ◽  
Masakazu Kaneko ◽  
Kou Suzuki ◽  
Yujiro Matsuoka
Keyword(s):  
Superior Vena Cava ◽  
Coronary Sinus ◽  
Superior Vena ◽  
Vena Cava ◽  
Right Atrial ◽  
Left Superior Vena Cava ◽  
Persistent Left Superior Vena ◽  
The Right
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