心房颤动患者窦房结分布及上腔静脉肌袖的三维电解剖标测

目的:通过三维电解剖标测系统观察心房颤动(房颤)患者上腔静脉肌袖结构,了解窦房结分布特点。方法:选取2018年1月至2020年1月于南京医科大学第一附属医院心血管内科接受射频导管消融隔离上腔静脉的房颤患者80例,男49例,女31例,年龄(59.3±8.9)岁,年龄范围18~75岁。其中阵发性房颤55例,持续性房颤25例...     

上腔静脉支架术治疗心脏起搏器引起的上腔静脉综合征

1973年Ｗｅｒｔｈｅｉｍｅｒ等[1] 首次报道经静脉心内膜起搏可以引起上腔静脉综合征 (ｐａｃｅｍａｋｅｒ ｉｎｄｕｃｅｄｓｕｐｅｒｉｏｒｖｅｎａｃａｖａｓｙｎ ｄｒｏｍｅ,ＰＳＶＣＳ)。其后 ,随着永久性心脏起搏器的广泛应用 ,ＰＳＶＣＳ的发生率日渐增多 ,文献报道为 1/ 10 0 0～ 1/ 40 0 0 0 [2 ] 。1994年Ｌｉｎｄｓａｙ等[3] 首次报道采用经皮穿刺上腔静脉预扩张后置入支架治疗ＰＳＶＣＳ ,取得了良好效果 ,但迄今文献累计报道只有 4例[3～ 6] ,现就ＰＳＶＣＳ的发病机制和上腔静脉支架术的临床应用作一简要综述。1　ＰＳＶＣＳ的…     

上腔静脉综合征

50年代前认为,上腔静脉综合征的病因主要是主动脉瘤和纵隔炎等良性病变,目前认为主要是肺癌和淋巴瘤等恶性病变,但由于诊治措施所致静脉内创伤引起者也见增多。本文综述上腔静脉综合征的病理生理、诊治措施及其预后。     

犬上腔静脉肌袖与右房心肌某些通道亚单位mRNA的表达

目的研究犬上腔静脉肌袖与右房游离壁快速激活延迟整流钾电流(IKr),L型钙电流(ICa-L),短暂外向钾电流(Ito)通道亚单位mRNA表达水平。方法8只健康杂种犬,取上腔静脉肌袖及右房游离壁,采用逆转录聚合酶链反应的方法测定IKrα亚单位ERG、ICa-Lα1亚单位CaV1.2、Itoα亚单位Kv4.3及β亚单位KChIP2mRNA表达水平并进行半定量分析。结果上腔静脉肌袖中ERG表达水平高于右房(P<0.05),而CaV1.2、Kv4.3、KChIP2的mRNA表达均低于右房(P<0.05)。结论上腔静脉肌袖与右房之间存在离子通道基因表达水平的差异。     

腔静脉肌袖Cx40/Cx43与心房颤动的相关研究进展

腔静脉肌袖内肌纤维走行紊乱,厚薄不均及肌纤维的不连续性都促成了心律失常的发生。腔静脉肌袖内缝隙连接蛋白表达丰富,其中Cx43表达浓度较高,Cx40表达浓度较低,且具有非典型分布,这为心房颤动发生提供了解剖学基础。心房颤动促进腔静脉内缝隙连接蛋白的重构,而其重构又促进了房颤的维持。     

阵发性心房颤动患者上腔静脉肌袖与心房的电学连接特征

总结 16例阵发性心房颤动患者上腔静脉 (SVC)肌袖的电生理标测和导管射频消融电隔离的结果 ,评价SVC肌袖和心房电连接的类型和特点。在环状标测电极指导下 ,对 16根SVC肌袖进行电位的记录、分析以及开口部的点或段的消融电隔离治疗。根据窦性心律和心房起搏下的肌袖内环形电极标测的袖电位激动顺序 ,即电突破点的数目和位置 ,以及有效放电对袖电位及其电突破点的影响 ,总结和分析袖房之间的电连接类型和特点。结果 :共标测和电隔离SVC肌袖 16根。其中呈单束状电连接 8根 (5 0 % ) ,双束状电连接 7根 (43.7% ) ,多束状电连接 1根 (6 .3% )。 16根SVC平均每根电连接束为 1.6± 0 .6根 ,共消融 2 .1± 0 .6个节段和部位 ,每个部位进行了2 .3± 0 .7次的放电。所有病例均达到完全电隔离的标准。结论 :SVC袖房之间电连接的类型多为单束状和双束状 ,在袖房连接处行点或节段性消融即可达到完全袖房电隔离的结果。     

上腔静脉综合征的诊治现状

上腔静脉综合征(Superior Vena Cave Syndrome,简称SVCS)是由于各种原因造成上腔静脉部分或完全阻塞,所引起的一组以头颈上肢和胸部静脉回流受阻,静脉压升高,侧支循环形成为主要临床征象的一组征侯群。1 病 因 引起上腔静脉综合征的原因很多,自1757年Hunter首先报告一例SVCS由主动脉瘤压迫引起以来,逐渐发现上纵隔的原发或转移性肿瘤,上腔静脉内外的炎性病变均可导致SVCS,但多为恶性肿瘤所致,据统计恶性肿瘤引起者占80％,良性病变引起者占     

兔肺静脉心肌袖组织学特性研究

近年来随着导管射频消融治疗心房颤动 (房颤 )技术的开展 ,发现大多数阵发性房颤起源于肺静脉入口近段[1 4 ] ,提示肺静脉在房颤的发生中起重要作用。肺静脉注入左心房后壁 ,与心房连接处无瓣膜 ,组织学上可看到肺静脉入口处的平滑肌细胞中有横纹肌成分 ,即心肌细胞呈类似袖套样延伸到肺静脉内 ,而且上肺静脉比下肺静脉的袖套样结构更宽更完善[5] ,形成心肌袖 (myocardialsleeve)。本实验通过对兔肺静脉肌袖解剖结构及组织学特性的观察探讨局灶性房颤起源于肺静脉的形态学基础。资料和方法实验标本的取材　健康新西兰大耳白兔 12只 ,雌雄不…     

Remodeling of myocardial sleeve and gap junctions in canine superior vena cava after rapid pacing

Objective We studied the response of the superior vena cava (SVC) myocardial sleeve to atrial fibrillation (AF). Methods and results We examined adult male dogs without pacing (N=6) and after rapid atrial pacing (600 bpm) for 2 weeks (P2w; N=5) and 6–8 weeks (P6–8w; N=5). After pacing, the sleeve was increased in thickness (non-paced vs. either paced group, both P<0.05). This was associated with an increase in proliferative activity, which was higher in the P2w than the P6–8w animals (P < 0.05). In addition, collagen content increased, and the component cardiomyocytes become more unevenly oriented and shorter and narrower in shape (non-paced vs. either paced group, both P < 0.05). Pacing had different effects on connexin40 (Cx40) and Cx43 gap junctions. There was a 98% increase in Cx43 signal in P2w, and a 74% increase in P6–8w animals (non-paced vs. each paced group, both P < 0.05). In contrast, Cx40 signal decreased 47% in P2w but increased 44% in P6–8w animals (non-paced vs. each paced group, both P < 0.05). Conclusions Rapid atrial pacing results in a specific pattern of remodeling of the canine SVC sleeve, including changes in size and shape, spatial orientation, and gap junction expression profile of the component cardiomyocytes. These changes may co-operatively affect the electrical properties and contribute to the formation and maintenance of the arrhythmogenic substrate of AF.     

Two atrial reentrant tachycardias originating from the superior vena cava: Electrophysiological characteristics and radiofrequency ablation

A case with two different types of atrial reentrant tachycardia of superior vena cava (SVC) origin is presented. Recent clinical studies have shown that the origin of focal atrial tachycardia typically lies in the venous structures connecting to both atria—the coronary sinus, the superior and inferior vena cava, and the pulmonary vein. These foci have atrial muscle fiber extensions which have electrophysiological characteristics essential to generation of focal ectopic firing. However, little is known about reentrant mechanism of these venous structures. In this report, we present a case of two atrial tachycardias (SVT1 and SVT2) independently originating from the SVC. SVT1 had 430 ms of tachycardia cycle length, and SVT2 had 390 ms of tachycardia cycle length. Both of them showed the character of reentry, and their earliest activations were recorded in the SVC. They were successfully eliminated by focal radiofrequency ablation in the SVC.     

Case report of fatal complication of superior vena cava tear from balloon dilatation of iatrogenic superior vena cava narrowing

The treatment options for superior vena cava (SVC) obstruction depends on the cause and severity of SVC narrowing. It ranges from conservative medical management to more elaborate endovascular and surgical repair of obstruction. There has always been a concern regarding the possibility of rupture of SVC during balloon dilatation, if the obstruction is secondary to the surgical cause. Very few cases are reported in the literature. We report a case of fatal complication of SVC tear in a 2-month-old child who had iatrogenic SVC narrowing.     

Effects of verapamil on superior vena cava electrical remodeling induced by short-term pacing from right atrium and superior vena cava in human

BackgroundAlthough the superior vena cava (SVC) may be involved in the triggering or maintenance of atrial fibrillation (AF), the electrophysiological properties of SVC in human are ill-defined.MethodsThe baseline effective refractory periods (ERPs) of high right atrium (HRA), SVC and the conduction time (CT) between HRA and SVC were measured at pacing cycle lengths (PCL) of 600 and 400 ms respectively in 20 patients (12 females, age 46 ± 13 years) with paroxysmal supraventricular tachycardia. Immediately after acute electrical remodeling (ER) induced by constant HRA or SVC pacing at PCL of 400 ms for 5 min, ERPs of HRA, SVC and the CT between HRA and SVC were determined. After verapamil was administered, the same protocols for determining ERPs of HRA, SVC and the CT between HRA and SVC were repeated.ResultsThe baseline ERP of SVC was significantly longer than that of HRA. The CT from SVC to HRA was significantly longer than that from HRA to SVC. After acute ER, both the ERPs of HRA and SVC were significantly shortened. However, no significant changes of the CT between HRA and SVC could be demonstrated. After verapamil infusion, significant shortening of the ERP of HRA and SVC still occurred following acute ER and the ERP of SVC was still longer than that of HRA.ConclusionsIn human, ER can occur both in HRA and SVC after a short and moderately rapid heart rate pacing either from HRA or SVC. Verapamil cannot prevent such ER from occurring.     

支架置入术治疗上腔静脉综合征

目的　观察支架置入治疗上腔静脉综合征的临床疗效。方法　采用经皮静脉内支架置入术治疗 12例上腔静脉综合征患者 (男 11例 ,女 1例 ,平均年龄 5 1岁 )。结果　上腔静脉综合征缓解率为 92 % (11 12 ) ,无早期血管堵塞、支架移位等临床并发症 ,复发率 16 7%。结论　经皮静脉内支架置入术治疗上腔静脉综合征缓解率高 ,相对安全简单 ,并发症少。     

Doppler superior vena cava flow evolution and respiratory variation in superior vena cava syndrome

BACKGROUND: Superior vena cava syndrome (SVCS) is a clinical expression of obstruction of blood flow through the superior vena cava. The patterns of the Doppler flow changes of superior vena cava (SVC), especially the respiratory effects on them have not yet been fully elucidated. This study was to examine SVC Doppler flow patterns and the respiratory effects on them in healthy subjects and patients with SVCS. METHODS: The SVC Doppler flow patterns of 18 normal human subjects and 22 patients with SVCS were analyzed at initial diagnosis and were followed up every 2 months for at least 11 months. RESULTS: Among the 22 patients, 5 patients with the tumor near the right atrium oppressing the inferior segment of the SVC had clear VR- and AR-waves, while in the other 17 patients the VR- and AR-waves disappeared or their outlines were vague. The respiratory variations of the S- and D-waves as a percentage change in inspiration compared to expiration in patient group were much lower than those in control group (S-wave: 1.67 +/- 3.32% vs. 15.65 +/- 16.15%, P = 0.0003; D-wave: 1.80 +/- 1.12% vs. 23.55 +/- 37%, P = 0.0087), which gradually became larger with treatment and showed no significant difference with those in control group after 7 months. CONCLUSIONS: The Doppler flows of the patients with SVCS correlate well with the images of CT scan of them. The respiratory variation of the S- and D-velocities could be used to evaluate the severity of SVC obstruction and its therapeutic effect.     

Identifying far-field superior vena cava potentials within the right superior pulmonary vein

BACKGROUND: Far-field extra-pulmonary vein (PV) potentials originating from the left atrial appendage and adjacent left atrium have been identified within the left PVs, but no systematic study of extra-PV potentials within the right superior PV (RSPV) has been described. OBJECTIVES: The purpose of this study was to prospectively analyze extra-PV contributions to RSPV potentials. METHODS: In a consecutive, prospective series of 114 patients (96 men and 18 women; 56 +/- 10 years) undergoing electrophysiologically guided ostial PV isolation, residual potentials recorded with a circular mapping catheter in the RSPV after ostial isolation were analyzed. Their extra-PV origin was validated by mapping a site with identical timing (in sinus rhythm or atrial fibrillation) within the adjacent superior vena cava (SVC) where, in sinus rhythm, local pacing (until threshold amplitude) concealed the residual potential within the stimulus artifact because of very short activation timing. The timing of residual potentials with respect to surface ECG P-wave onset was measured and compared with the earliest timing of ablated RSPV potentials. RESULTS: Residual low-amplitude (mean 0.29 +/- 0.17 mV, range 0.07-0.65 mV) extra-PV potentials were recorded from the anterior and superior aspect of the RSPV in 3.6 +/- 1 bipoles in 26 (23%) patients (all men, 51 +/- 10 years) with a timing from sinus P-wave onset of 17 +/- 12 ms (range 0-40 ms) vs 52 +/- 9 ms (range 35-70 ms) for the earliest RSPV potential (P <.001, t-test). Extra-PV potentials all originated from the posterior aspect of the SVC. The SVC potential was identified during ongoing atrial fibrillation in eight patients and later confirmed in sinus rhythm. An extra-PV potential of SVC origin could be identified by timing earlier than 30 ms from onset of the sinus P wave, with sensitivity of 92%, specificity 100%, positive predictive value 100%, and negative predictive value 89%. CONCLUSION: Extra-PV potentials of right-sided SVC origin were recorded within the RSPV in 23% of patients and can be identified with high sensitivity and specificity by a timing within 30 ms of sinus P-wave onset. Recognizing these potentials can avoid unnecessary additional ablation and possibly PV stenosis or phrenic paralysis.     

Bilateral superior vena cava with right superior vena cava draining into left atrium

Anomalies of systemic venous return are extremely heterogeneous congenital malformations with variable ranges from completely normal physiology to severe forms of right to left shunting requiring surgical treatment. Anomalous drainage of a right-sided superior vena cava (SVC) to the left atrium (LA) is one of the rarest variants of systemic venous return anomalies, characterized by right-to-left shunt physiology and cyanosis. Here we report a 2 years old girl presented with cyanosis which was observed shortly after birth by her parents but not further investigated. She is otherwise active girl and with normal growth and development. Her clinical examination was unremarkable apart from mild clubbing of the fingers and low oxygen saturation of 88–90% in room air. Her ECG and chest X-ray were unremarkable. Echocardiography showed bilateral SVC connected by a small innominate vein. The right SVC drains directly into the LA while the left SVC drains into the right atrium (RA) via a dilated coronary sinus. There is a small superior sinus venosus type atrial septum defect (ASD) with left to right shunt. Also, there is partial anomalous pulmonary venous return with right upper and right middle pulmonary veins draining directly into the right SVC, which is connected to LA. The right lower pulmonary vein and left pulmonary veins drain directly to LA. The rest of her echocardiography demonstrated normal heart structures and function. This patient was referred for surgical correction, including baffling of the right SVC to the RA and closure of the ASD. We describe this case to highlight the importance of recognizing this rare anomalous systemic venous connection as one of the very rare causes of cyanosis in the pediatric age group as well as at older age.     

Electrical connection between the right atrium and the superior vena cava,and the extent of myocardial sleeve in a patient with atrial fibrillation originating from the superior vena cava

We describe a case in which the superior vena cava (SVC) was electrically isolated by an application of radiofrequency energy to a point with electrical connection between the right atrium and the SVC in a patient with atrial fibrillation (AF) originating from the SVC. The connection was located in the posteroseptal region between the right atrium and the myocardial sleeve extending into the SVC. Local AF occurred after radiofrequency ablation and rapid activities were recorded all around the SVC, whereas the atrium was still in sinus rhythm. It is suggested that focal AF in the SVC contributes not only to the initiation but also to the maintenance of AF, and the myocardial sleeve extends into the SVC through a connection point to cover the entire internal lumen.