Prevalence of persistent superior vena cava and association with congenital heart anomalies

Association of Prenatally Diagnosed Isolated Single Left Superior Vena Cava and Postnatal Development of Coarctation of the Aorta

To report the prevalence of coarctation of the aorta (CoA) in fetuses with single left superior vena cava (SL-SVC) and to evaluate changes in echocardiographic measurements. Additionally, to report the prevalence of associated malformations. Retrospective observational study of fetuses diagnosed with SL-SVC between 2012 and 2021 at a tertiary fetal cardiology unit. In fetuses without intracardiac abnormalities, Z-scores of the ventricles, great arteries, and Doppler flow patterns are reported. We identified 47 fetuses with SL-SVC of which 8/47 (17%) had abnormal intracardiac anatomy. One fetus was lost to follow-up. Of those with normal intracardiac anatomy and postnatal follow-up (38), karyotype abnormalities were confirmed in 2/38 (5%) and ECA in 8/38 (21%). 33/38 were live-born. None developed CoA postnatally. Paired analysis of Z-scores between early and late scans of 24 fetuses showed that diameters of the right heart structures and Doppler flows of tricuspid valve increased significantly during pregnancy, while the left heart structures and flow patterns did not change. The median risk of CoA did not change between the early and the late scan. We did not observe CoA in this cohort. A degree of ventricular asymmetry was present, but this was due to right heart dominance rather than hypoplasia of left heart structures. This likely reflects redistribution of blood and does not appear to confer increased risk of CoA. Predictive models of the postnatal development of CoA which set the dimensions of right and left heart structures in relation might not be applicable in this situation.

Persistent left superior vena cava in right hemiarch replacement under deep hypothermic circulatory arrest: A case report

BACKGROUND

Persistent left superior vena cava (PLSVC), a relatively rare thoracic vascular malformation, can inconvenience perfusionists and operators when encountered during deep hypothermic circulatory arrest (DHCA).

CASE SUMMARY

Herein, we describe the case of a patient with concurrent giant aortic arch aneurysm, aortic stenosis, and PLSVC. To treat these conditions, we performed right hemiarch and aortic valve replacements under DHCA. Notably, we applied “bilateral superior vena cava retrograde cerebral perfusion (RCP)” for cerebral protection, which significantly optimized the surgical procedure and reduced the risk of postoperative complications. The patient was discharged 14 d after surgery with no complications.

CONCLUSION

Surgical intervention for PLSVC under DHCA can be performed using the bilateral superior vena cava RCP approach.

Persistent left superior vena cava isolation in patients with atrial fibrillation: Selective or empirical?

BACKGROUND

Persistent left superior vena cava (PLSVC) is the most prevalent form of thoracic venous abnormality and can serve as a significant arrhythmogenic source in atrial fibrillation (AF).

METHODS AND RESULTS

Among the 3950 patients who underwent radiofrequency ablation for AF between September 2014 to April 2020, 17 patients (mean age 59.4 ± 8.0 years, 64.7% male) with PLSVC were identified. Among them, nine patients (52.9%) had a prior history of pulmonary vein isolation (PVI) alone. Eight out of nine patients who experienced AF recurrence underwent PLSVC isolation with or without pulmonary vein (PV) reconnection. For the remaining eight patients (47.1%), PVI plus PLSVC isolation were performed during the index procedure. Ectopy originating from PLSVC was documented in 11 patients (64.7%) and successful PLSVC isolation was achieved in 16 patients (94.1%). After a median follow-up of 28.3 months, freedom from AF/ atrial tachycardia (AT) was observed in 13 patients (76.5%).

CONCLUSION

Empirical PLSVC isolation beyond PVI appears to be a feasible and safe strategy to prevent AF recurrence in patients with concomitant PLSVC.

Misdiagnosis of persistent left superior vena cava with unroofed coronary sinus as a coronary sinus-type atrial septal defect

Key Clinical Message

Awareness of persistent left superior vena cava (PLSVC) with unroofed coronary sinus is crucial. Pre- and perioperative evaluation of this association is necessary for surgical plan. Creating an intra-atrial tunnel to divert LSVC to right atrium without obstructing the mitral valve or the pulmonary veins is the safe surgical approach.

Abstract

Unroofed coronary sinus syndrome is a rare congenital heart defect representing less than 1% of all atrial septal defect (ASD) types, and may be associated with persistent left superior vena cava (PLSVC) which may be missed during preoperative diagnosis. Herein, we present a case of a 2-year-old patient who underwent an operation for repair of a coronary sinus-type ASD; however, PLSVC was detected intraoperatively. An antra-atrial tunnel has created to divert the flow of PLSVC into the right atrium along with the repair of the ASD.

Accidental Diagnosis of Isolated Persistent Left Superior Vena Cava After an Elective Central Venous Access Procedure for Chronic Hemodialysis: Clinical Implications and Precautions From a Case Report

Persistent left superior vena cava (PLSVC) is the most frequent thoracic venous anatomical variant in the general population. Isolated PLSVC, without formation of the right superior vena cava, is described in 10% of cases of PLSVC only. While it can be associated with congenital heart disease, arrhythmias, and premature death, adult patients with PLSVC are mostly asymptomatic, and the diagnosis is usually accidental. We present the case of a 72-year-old male with end-stage renal disease who was started on urgent hemodialysis through a temporary non-tunneled femoral central venous catheter (CVC) in the SLED (slow low-efficiency dialysis) modality and later remained dependent on hemodialysis. At this stage, placement of a tunneled CVC in the right internal jugular vein was necessary and fluoroscopy guidance was not available. There were no complications during the procedure, but postoperative conventional chest radiography revealed an inadequate positioning of the CVC tip in the left hemithorax, crossing the midline. Subsequently, the diagnosis of PLSVC was obtained by performing a thoracic angio-CT scan, confirming CVC tip positioning inside the PLSVC, and also excluded the presence of cardiac defects or additional anatomical variations of the great vessels of the thorax. Early evaluation for the creation of autologous vascular access was started under our care, and there were no mechanical or other complications associated with hemodialysis sessions during early follow-up after discharge.

Bilateral inferior venae cava combined with the persistent left superior vena cava and hemiazygos continuation of left inferior vena cava with drainage into right atrium: A case report

The persistent left superior vena cava (PLSVC) is a common venous abnormality. However, malformation of the bilateral inferior venae cava (IVC) is extremely rare, with an incidence rate of .3%. IVC malformation is associated most frequently with heart defects and isomerism and often has a poor prognosis. We presented a case of vascular malformations in the fetus of bilateral caval veins with the interruption of the left-sided venous return with hemiazygos continuation in presence of a right-sided inferior caval vein. Also noted were the PLSVC and a dilated right heart with a widened pulmonary trunk. In this case, there were no heart defects or chromosomal abnormalities, and the newborn postpartum was in a good condition.

High-density electro-anatomical activation mapping to guide slow pathway modification in patients with persistent left superior vena cava

BACKGROUND

Slow pathway (SP) mapping and modification can be challenging in patients with persistent left superior vena cava (PLSVC) due to anatomical variance of Koch's triangle (KT) and coronary sinus (CS) dilatation. There is a lack of studies using detailed 3-dimensional (3D) electro-anatomical mapping (EAM) to investigate conduction characteristics and guide ablation targets in this condition.

OBJECTIVES

To describe a novel technique of slow pathway mapping and ablation in sinus rhythm using 3D EAM in patients with PLSVC after validation in a cohort with normal coronary sinus anatomy.

METHODS

Seven patients with PLSVC and dual AV node physiology who underwent slow pathway modification with the use of 3D EAM were included. Twenty-one normal heart patients with AV nodal re-entrant tachycardias formed the validation group. High-resolution, ultra-high-density local activation timing (LAT) mapping of the right atrial septum and proximal coronary sinus in sinus rhythm was performed.

RESULTS

SP ablation targets were consistently identified by an area in the right atrial septum with the latest activation time and multi-component atrial electrogram (EGM) adjacent to a region with isochronal crowding (deceleration zone). In PLSVC patients, these targets were located at or within 1 cm of the mid anterior CS ostium. Ablation in this area led to successful SP modification reaching standard clinical endpoints with a median of 43 sec of radio frequency energy or 14 mins of cryoablation without complications.

CONCLUSION

High-resolution activation mapping of Koch's triangle in sinus rhythm can facilitate localisation and safe slow pathway ablation in patients with PLSVC.

A Rare Presentation of Duplicate Superior Vena Cava Precipitating Premature Atrial Contractions: A Case Report and a Review of the Literature

Millions of central lines are placed each year worldwide for life-saving measures. We present a case of left internal jugular (IJ) triple lumen catheter (TLC) placement for life-saving vasopressors, which appeared to be in the left mediastinum after a confirmed chest X-ray. After correlation with a previous MRI of the heart with and without contrast, duplication of the superior vena cava (SVC), also known as persistent left SVC (PLSVC), was discovered. PLSVC often causes no symptoms to affected individuals and is usually first found as an incidental finding discovered during thoracic surgeries, cardiovascular interventional procedures, and central line insertions. Placement of TLC or central venous catheter (CVC) can be challenging in such patients and may lead to life-threatening complications such as severe arrhythmias, cardiogenic shock, pneumothorax, and tamponade. Knowing such anomalies can prevent unnecessary catheter removal and help determine the origin of some arrhythmias and dilated heart chambers in these patients.

Provocation and Localization of Arrhythmogenic Triggers from Persistent Left Superior Vena Cava in Patients with Atrial Fibrillation

BACKGROUND

Although pulmonary vein isolation (PVI) is an established procedure for atrial fibrillation (AF), non-PV foci play a crucial role in AF recurrence. Persistent left superior vena cava (PLSVC) has been reported as critical non-PV foci. However, the effectiveness of provocation of AF triggers from PLSVC remains unclear. This study was designed to validate the usefulness of provoking AF triggers from PLSVC.

METHODS

This multicenter retrospective study included 37 patients with AF and PLSVC. To provoke triggers, AF was cardioverted, and re-initiation of AF was monitored under high-dose isoproterenol infusion. The patients were divided into two groups: those whose PLSVC had arrhythmogenic triggers initiating AF (Group A) and those whose PLSVC did not have triggers (Group B). Group A underwent isolation of PLSVC after PVI. Group B received PVI only.

RESULTS

Group A had 14 patients, whereas Group B had 23 patients. After a 3-year follow-up, no difference in the success rate for maintaining sinus rhythm was observed between the two groups. Group A was significantly younger and had lower CHADS2-VASc scores than Group B.

CONCLUSIONS

The provocation of arrhythmogenic triggers from PLSVC was effective for the ablation strategy. PLSVC electrical isolation would not be necessary if arrhythmogenic triggers are not provoked.

Computed tomography and magnetic resonance imaging of congenital thoracic systemic venous anomalies

We present the imaging findings of thoracic systemic venous anomalies diagnosed by computed tomography and magnetic resonance imaging. Persistent left superior vena cava is the commonest anomaly of the thoracic systemic veins encountered either incidentally as an isolated finding or associated with congenital heart disease. Inferior vena cava (IVC) interruption with azygos continuation is the second most common anomaly, which may also be isolated or be associated with left isomerism syndrome. The article will also discuss other rarer systemic venous anomalies including retroaortic brachiocephalic vein and IVC drainage into the left atrium. Finally, the impact of pre-procedure reporting of thoracic systemic venous anomalies on the choice of intervention and patient outcome will be addressed.

Persistent left superior vena cava: Case report

Persistent left superior vena cava (PLSVC) is a rare anomaly of the systemic venous circulation. We report the case of a 22-year-old female that had history of multiple repair surgeries for her esophageal atresia, as well as a right lobectomy for bronchiectasis 15 years prior. She was admitted to the surgical ward for complete resection of the right lung. A trans-thoracic echocardiography was performed as part of the pre-surgical work-up and it revealed a dilated coronary sinus which led us to suspect the presence of a PLSVC. The latter was confirmed by a simple “Bubble study” and confirmed by CT angiogram. We will discuss throughout this paper, the clinical and radiological features, as well as the embryology of this anomaly, so that the knowledge of the existence of this anatomical variant, especially if surgery or catheterization is at reach of the medical team, may lead to avoid serious complications.

Catheter ablation for atrial fibrillation in patients with persistent left superior vena cava: Case series and systematic review

Introduction

Persistent left superior vena cava (PLSVC) is the most common form of thoracic venous abnormality. Catheter ablation (CA) for atrial fibrillation (AF) can be complicated by the existence of PLSVC, which could act as an important arrhythmogenic mechanism in AF.

Methods and results

We reported a case series of patients with PLSVC who underwent CA for AF at our center between 2018 and 2021. A systematic search was also performed on PubMed, EMBASE, and Web of Science for research reporting CA for AF in patients with PLSVC. Sixteen patients with PLSVC were identified at our center. Ablation targeting PLSVC was performed in 5 patients in the index procedures and in four patients receiving redo procedures. One patient experienced acute procedure failure. After a median follow-up period of 15 months, only 6 (37.5%) patients remained free from AF/atrial tachycardia (AT) after a single procedure. In the systematic review, 11 studies with 167 patients were identified. Based on the included studies, the estimated prevalence of PLSVC in patients undergoing CA for AF was 0.7%. Ablation targeting PLSVC was performed in 121 (74.7%) patients. Major complications in patients with PLSVC receiving AF ablation procedure included four cases of cardiac tamponades (2%), three cases of cardiac effusion (1.5%), one case of ischemic stroke, and three cases of phrenic nerve injury (1.5%) (one left phrenic nerve and two right phrenic nerve). Pooled analysis revealed that after a median follow-up period of 15.6 months (IQR 12.0–74.0 months), the long-term AF/AT-free rate was 70.6% (95% CI 62.8–78.4%, I² = 0.0%) (Central illustration). Different ablation strategies for PLSVC were summarized and discussed in the systematic review.

Conclusion

In patients with PLSVC, recurrence of atrial arrhythmia after CA for AF is relatively common. Ablation aiming for PLSVC isolation is necessitated in most patients. The overall risk of procedural complications was within an acceptable range.

Pictorial Essay: Understanding of Persistent Left Superior Vena Cava and Its Differential Diagnosis

Persistent left superior vena cava (PLSVC) is a rare congenital, thoracic, and vascular anomaly. Although PLSVCs generally do not have a hemodynamic effect, several types of PLSVC and some cardiac anomalies may manifest with clinical symptoms. The presence of PLSVC can render catheterization via left subclavian access difficult when placing a pacemaker or central venous catheter. As such, recognizing a PLSVC that is typically incidentally discovered can prevent complications such as vascular injury. Differentiating vessels found in a similar location as PLSVC is necessary when performing thoracic vascular procedures. This pictorial essay explains the multi-detector CT findings of a PLSVC, and provides a summary of other blood vessels that require differentiation during thoracic vascular procedures.

Case report: PICC line for a toddler with bilateral bidirectional Glenn shunt, Fontan circulation, and persistent left superior vena cava

Performing peripherally inserted central catheters for children with bilateral bidirectional Glenn shunt, Fontan circulation, and persistent left superior vena cava differs from those with normal central venous anatomy. This study presents two PICC procedures for a toddler with this condition to demonstrate an accurate PICC approach for such children.

Children with bilateral bidirectional Glenn shunt, Fontan procedure, and persistent left superior vena cava require an unique PICC placement approach to prevent unexpected complications. Hence, it is extremely important to provide nurses with knowledge about this altered central venous anatomy and explicitly outline in the PICC placement guidelines.

Pulsed Field Ablation for Persistent Superior Vena Cava: New Solution for an Old Problem

Persistent left superior vena cava (PLSVC) is a known arrhythmogenesis site in patients with atrial fibrillation. However, the optimal PLSVC isolation approach has remained unclear because of the potential risk of complications. The current study reports 2 cases of successful electrical PLSVC isolation using pulsed field ablation. (Level of Difficulty: Intermediate.).

A six-chambered heart: cor triatriatum sinister with double-chambered right ventricle in association with ventricular septal defect

Background

Cor triatriatum has been described as a heart with three atria in which the left atrium (cor triatriatum sinistrum) or right atrium (cor triatriatum dextrum) is divided into two compartments by a fold of tissue, a membrane, or a fibromuscular band. Double-chambered right ventricle, on the other hand, is identified by the presence of an anomalous muscle bundle dividing the right ventricle into two chambers.

Case presentation

Here, we describe the case of a child who had a combination of both of these rare entities, effectively creating a heart with six chambers. The child underwent a successful intracardiac repair.

Conclusions

The association of CTS with DCRV forming a “6-chambered heart” is extremely rare. Awareness of its existence and accurate preoperative diagnosis has important implications in its surgical repair with all the components of this disease spectrum, further increasing the complexity of a successful surgical repair.

Case report: Thoracoscopic ablation for a patient with atrial fibrillation and persistent left superior vena cava

Persistent left superior vena cava (PLSVC) is a relatively rare congenital anomaly in the general population. It plays an important role in initiating and maintaining atrial fibrillation (AF) in some patients. Radiofrequency catheter ablation is the major treatment for patients with AF and PLSVC in most publications. Here, we reported a case of thoracoscopic ablation for a patient with atrial fibrillation and persistent left superior vena cava. After preprocedural simulation using virtual reality, we successfully completed box-lesion, ablation line from superior vena cava to inferior vena cava, left atrial appendage (LAA) excision, and PLSVC ablation. It provides a new perspective on surgical treatment for patients with AF and PLSVC.

Persistent left superior vena cava transvenous lead extraction: A European experience

BACKGROUND

Transvenous lead extraction (TLE) is rising in parallel to cardiac implantable electronic device implantations. Persistent left side superior vena cava (PLSVC) is a relatively common anatomical variant in the healthy population; TLE in patients with a PLSVC is rare.

METHOD

Data were collated from 6 European TLE institutes of 10 patients who had undergone lead extraction with a PLSVC. Patient demographics, procedural challenges and outcomes were reported.

RESULTS

Ten patients aged 73.4 ± 7.8 years (60% male) underwent TLE of 20 leads (3 left ventricle, 10 right ventricle, 7 right atrium) with dwell time of 82.95 ± 39.1 months. Of the 10 cases, 4 had an infection indication and 5 were biventricular system extractions; 25% of the extracted leads were defibrillator leads. The majority of the procedures were completed in the cardiac catheterization suite (80%) under general anaesthesia (60%) by cardiologists (80%) using a rotational powered sheath (65%). The Tandem approach was used successfully in 3 cases. Complete procedural success was obtained in 100% of cases in the absence of complications within 127.4 ± 74.7 min. There was no 30-day mortality.

CONCLUSION

TLE in PLSVC is feasible albeit rare. Standard extraction techniques in experienced hands are associated with favorable outcomes; the Tandem procedure may be an additional technique to improve the safety and efficacy of TLE in PLSVC.

Superior Vena Cava Syndrome

Superior vena cava (SVC) syndrome comprises a constellation of clinical signs and symptoms caused by obstruction of blood flow through the SVC. The management of patients with life-threatening SVC syndrome is evolving from radiation therapy to endovascular therapy as the first-line treatment. There is a paucity of data and societal guidelines with regard to the management of SVC syndrome. This paper aims to update the practicing interventionalists with the contemporary and the evolving therapeutic approach to SVC syndrome. In addition, the review will focus on endovascular techniques, including catheter-directed thrombolysis, angioplasty, and stenting, and their associated complications.

Transvenous lead extraction in patients with persistent left superior vena cava

PURPOSE

Predictors of difficulty and complications of transvenous lead extraction (TLE) have been investigated in several studies; however, little is known about the venous anatomical characteristics that can have an impact on procedural outcomes. Among them, the persistent left superior vena cava (PLSVC) is a common anomaly often discovered incidentally during cardiac device implantation and could raise concerns if TLE is indicated. We report technical considerations and outcomes of TLE for two patients with leads implanted via PLSVC.

METHODS AND RESULTS

Two cardiac implantable electronic device recipients with isolated PLSVC required TLE due to infective endocarditis in one case and lead failure in the other. In the first case, TLE procedure was performed in a hybrid operating room with minimally invasive video-assisted thoracoscopic monitoring due to the high procedural risk. Two active fixation 20-year-old pacing leads were removed with a relatively short fluoroscopy time. In the second case, we successfully extracted a single-coil active fixation lead without the need of a locking stylet or advanced extraction tools. There were no procedural complications or adverse events at 1-year follow-up.

CONCLUSION

TLE procedures for two patients with isolated PLSVC were successfully completed with less difficulty and tools than expected based on the characteristics of the targeted leads. If indicated, TLE in the presence of a PLSVC should be considered in experienced centers.

Persistent left superior vena cava: clinical importance and differential diagnoses

Persistent left superior vena cava (PLSVC) is the most common thoracic venous anomaly and may be a component of the complex cardiac pathologies. While it is often asymptomatic, it can lead to significant problems such as arrhythmias and cyanosis. Besides, it can cause serious complications during vascular interventional procedures or the surgical treatment of cardiac anomalies (CA). The clinical significance of PLSVC depends on the drainage site and the accompanying CA. In this article, we will describe the epidemiology, embryology, and anatomic variations of PLSVC. Possible accompanying CA and heterotaxy spectrum will be reviewed with the help of multidetector computed tomography (MDCT) images. Radiological pitfalls, differential diagnoses, and the clinical importance of PLSVC will be highlighted.

Cardiac implantable electronic devices in patients with persistent left superior vena cava-A single center experience

BACKGROUND

There are limited data on cardiac implantable electronic device implantation (CIED) in patients with persistent left superior vena cava (PLSVC).

OBJECTIVE

To describe the outcomes of implanting CIEDs with a focus on cardiac resynchronization therapy (CRT) in patients with PLSVC.

METHODS

We identified all patients with a PLSVC that underwent CIED implantation from December 2008 until February 2019 at our institution by querying the electronic medical record (n = 34). We then identified controls in a 3:1 fashion (n = 102) by matching on device type (CRT vs non-CRT). Procedure success, complications, fluoroscopy and procedural time were recorded. Outcomes were compared using a two-way analysis of variance test and conditional regression modeling for continuous and categorical variables, respectively.

RESULTS

A total of 34 patients with PLSVC underwent 38 procedures. Four patients underwent dual chamber system implantation followed by a subsequent upgrade to CRT. Thirteen patients underwent CRT implantation: one was implanted via the right subclavian while the rest were implanted via the PLSVC. Left ventricular (P = .06). Procedure and fluoroscopy times were significantly higher in the PLSVC as compared with the control group (97.7 vs 66.1 minute, P < .001 and 18.1 minute vs 8.7 minutes, P = .005, respectively).

CONCLUSION

CIED implant in patients with PLSVC is feasible but technically more challenging and appears to be associated with higher risk of right ventricular lead dislodgment.

Left Superior Vena Cava in the Fetus: A Rarely Isolated Anomaly

The frequency of chromosomal anomalies among fetuses with isolated persistent left superior vena cava (PLSVC) is still debated. The objective of the present study was to assess the prevalence of genetic and morphological anomalies identified in fetuses with PLSVC. We conducted a single-center retrospective study including all fetuses diagnosed with a PLSVC between 2010 and 2017. PLSVC was categorized as isolated or associated according to antenatal diagnosis of associated congenital heart defects, hypoplastic aortic isthmus, abnormal venous/arterial connections, and extracardiac anomalies. Among 229 fetuses diagnosed with PLSVC, 39 cases (17%) were strictly isolated and no syndromic/genetic anomaly or aortic coarctation was diagnosed. Seventy-two fetuses had a cardiovascular defect with a rate of genetic anomalies of 22%, 29 had an extracardiac malformation, and 89 had both an extracardiac and a cardiovascular defect. Among fetuses with abnormal development of the arterial/venous system as the only associated anomaly such as aberrant right subclavian artery or absent ductus venosus, 22% had a genetic anomaly. Overall, sixty-five fetuses or infants had a genetic concern, including 23 aneuploidies, 15 pathogenic micro-deletions/duplications, and 5 variants of unknown significance; 12 patients had VACTERL association, and 12 heterotaxy syndrome. Seven infants had an aortic coarctation diagnosed at birth.In conclusion, a thorough prenatal ultrasound examination is paramount, and the identification of variants of the venous/arterial system in addition to PLSVC should raise suspicion for genetic or morphologic abnormalities. Invasive prenatal diagnosis with array-CGH should be offered when PLSVC is non-isolated, after a detailed ultrasound evaluation in a tertiary center.

Left superior vena cava: cross-sectional imaging overview

Persistent left-sided superior vena cava (PLSVC) is the commonest systemic venous anomaly in the thorax with a reported prevalence of up to 0.5% in otherwise normal population and up to 10% in patients with congenital heart disease (CHD). In the absence of associated CHD, it is usually asymptomatic, discovered incidentally. It may complicate catheter or pacemaker lead placement. PLSVC typically drains into the right atrium through the coronary sinus. In children with CHD, the presence of a PLSVC may affect the choice of certain surgical procedures. PLSVC is significantly more common in association with situs ambiguous than with situs solitus or inversus, up to 60-70%. In patients with situs ambiguous, the drainage of LSVC is variable, more commonly directly into the atria rather than through the coronary sinus (CS). Rarely, there is a PLSVC draining into the CS with absent right SVC. PLSVC draining into the right atrium via the CS will not usually cause blood shunting between the right and the left sides. However, shunting occurs when PLSVC is associated with unroofed CS, or when it directly drains into the left atrium. With an increased use of CT and MRI for chest and cardiac imaging, PLSVC is being more encountered by radiologists than before. In this article, we will discuss the embryology of PLSVC, its anatomic course and drainage pathways, as well as its clinical relevance and relation to congenital heart disease and viscero-atrial situs.

Impact of persistent left superior vena cava on radiofrequency catheter ablation in patients with atrial fibrillation

AIMS

The impact of persistent left superior vena cava (PLSVC) in atrial fibrillation (AF) patients undergoing radiofrequency catheter ablation (RFCA) is not well known. We performed this analysis to evaluate the electrophysiological characteristics of PLSVC and its role in triggering and maintaining AF.

METHODS AND RESULTS

Patients with AF referred to two tertiary hospitals were screened and patients with PLSVC in pre-RFCA imaging studies were enrolled. Among 3967 patients, PLSVC was present in 36 patients (0.9%). There were four morphological types of PLSVC: type 1, atresia of the right superior vena cava (SVC) (n = 2); type 2A, dual SVCs with an anastomosis between right and left SVCs (n = 15); type 2B, dual SVCs without an anastomosis (n = 16); type 3, PLSVC draining into the left atrium (LA; n = 2); and unclassified in one patient. Thirty-two patients underwent RFCA and electrophysiology study focusing on PLSVC: PLSVC was the trigger of AF in 48.4% of patients and the driver of AF in 46.9% of patients. Cumulatively, PLSVC was a trigger or driver of AF in 22 patients (68.8%). Whether to ablate PLSVC was determined by the results of electrophysiology study, and no significant difference in the late recurrence rate was observed between patients who did and did not have either trigger or driver from PLSVC.

CONCLUSION

Pre-RFCA cardiac imaging revealed PLSVC in 0.9% of AF patients. This study demonstrated that PLSVC has an important role in initiating and maintaining AF in substantial proportion of patients. Electrophysiology study focusing on PLSVC can help to decide whether to ablate PLSVC.

Electrophysiological features and radiofrequency catheter ablation of supraventricular tachycardia in patients with persistent left superior vena cava

BACKGROUND

The electrophysiological features and roles of persistent left superior vena cava (PLSVC) in supraventricular tachycardia (SVT) are not known.

OBJECTIVE

The purpose of this study was to elucidate the electrophysiological features and roles of PLSVC in patients with SVT.

METHODS

We included 37 patients with PLSVC (mean age 43.5 ± 17.1 years; 35.1% men) and 510 patients without PLSVC (mean age 43.9 ± 18.8 years; 48.2% men) who underwent an electrophysiology study for SVT. The number of induced tachycardias, location of the slow pathway (SP) or accessory pathway (AP), and radiofrequency catheter ablation (RFCA) outcomes were compared between patients with and without PLSVC. During RFCA of the left AP, a coronary sinus (CS) catheter was placed into the left superior vena cava (left superior vena cava group) or the great cardiac vein (great cardiac vein group). The RFCA outcomes were compared between the groups.

RESULTS

In patients with PLSVC, 40 tachycardias were induced: atrioventricular nodal reentrant tachycardia (AVNRT) (n = 19), atrioventricular reentrant tachycardia (n = 17), and focal atrial tachycardia (n = 4). Among patients with AVNRT, an SP in the CS was significantly more frequent in patients with PLSVC than in those without PLSVC (47.4% vs 3.8%; P < .001). In patients with the left AP, the number of RFCA attempts and recurrence were lower in the great cardiac vein group than in the left superior vena cava group.

CONCLUSION

An SP in the CS is prevalent in patients with AVNRT and PLSVC. It is useful to place a CS catheter into the great cardiac vein in patients with a left AP and PLSVC.

Inability to Utilize Retrograde Cardioplegia due to a Persistent Left Superior Vena Cava

A persistent left superior vena cava is a congenital abnormality that affects a minority of the general population. While this finding is not hemodynamically significant in all patients, failure to recognize the altered anatomy in any of these patients can be consequential during procedures such as central venous catheter placement, pacemaker/defibrillator wire placement, and use of retrograde cardioplegia during cardiac surgery. We present a case of an intraoperative diagnosis of a persistent left superior vena cava that altered the original plan to arrest the heart using retrograde cardioplegia. Echocardiography was instrumental in this diagnosis and avoided potentially inadequate myocardial protection during cardiopulmonary bypass.

Association of A Dilated Coronary Sinus in the Fetus with Actual and Apparent Coarctation of the Aorta and Diminutive Left Heart Structures

Evidence suggests an association between left heart obstructive lesions and dilated coronary sinus (DCS), but this has not been studied in fetuses. A retrospective review of fetal echocardiograms (FE) over an 8-year period was conducted, and patients with DCS were identified and confirmed postnatally. There were 5840 FE performed on 4920 women during this period. Of 49 patients with DCS, 22 had normal intracardiac anatomy and 27 patients had congenital heart disease (CHD) yielding an incidence of 4.6 % in the presence of CHD (27/584). Of 27 patients with DCS and CHD, approximately a third had either hypoplastic left ventricles and/or coarctations (10/27, 37 %). The incidence of left heart obstructive lesions was much higher in the presence of a DCS (37 % vs 45/557, 8 %, p < 0.0001). The odds ratio of left heart hypoplasia in fetuses with CHD and a DCS was 6.6 (95 % CI 2.8-15.3). Comparison of patients with postnatally confirmed coarctation with those with normal intracardiac anatomy with DCS, revealed that in the former, the right ventricle (p = 0.005), pulmonic valve annulus (p = 0.0001) and the tricuspid inflow were larger (p = 0.001) compared to corresponding left-sided structures. The size of the DCS was not significantly different between the two groups, but in the former, the DCS was more closely related to the posterior leaflet of the mitral valve and caused a significant diminution of the mitral inflow. Our study suggests a strong association, possibly causal, between left heart obstructive lesions and DCS in utero.

Clinical characteristics of prenatally diagnosed persistent left superior vena cava in low-risk pregnancies

Objective

To determine the incidence and clinical characteristics of persistent left superior vena cava (PLSVC) among low‐risk pregnancies. We have also compared electrocardiography (ECG) parameters of infants with PLSVC with those of normal controls.

Method

At our institute, fetal echocardiogram is routinely performed in the midtrimester. We retrospectively reviewed the records of prenatally diagnosed PLSVC cases from 2010 to 2014. The ECG findings in infants with isolated PLSVC were compared with those of age‐matched controls.

Results

Sixty‐five cases of fetal PLSVC were detected during the study period. It represents 0.36% (65/18 188) of all fetal echocardiographic examinations during the study period. Twenty cases (30.8%) had other cardiac anomalies, seven cases (10.8%) were associated with extracardiac anomalies, and four cases (6.2%) had both cardiac and extracardiac anomalies, whereas in 34 cases (52.3%), the anomaly was isolated. There were no significant differences in ECG parameters between neonates with PLSVC and normal controls.

Conclusion

Detection of PLSVC should prompt careful search for associated anomalies. Isolated PLSVC is a benign vascular anomaly and the outcomes are excellent. © 2016 The Authors. Prenatal Diagnosis published by John Wiley & Sons, Ltd.

What's Already Known About This Topic?

Persistent left superior vena cava (PLSVC) can be accurately diagnosed prenatally and can be associated with cardiac and extracardiac anomalies.

The significance of PLSVC when isolated is unclear.

What Does This Study Add?

We establish the incidence and clinical characteristics of PLSVC in low‐risk pregnancies.

Electrocardiographic parameters in neonates with PLSVC are similar to those of unaffected controls.