Left Superior Vena Cava Research Articles

Clinical features and genetic analysis of two fetuses with ring chromosome 21 mosaicism

To investigate the perinatal clinical phenotype and genetic characteristics of two fetuses with ring chromosome 21 mosaicisms. Two fetuses who were diagnosed at the Xiamen Maternal and Child Health Care Hospital in November 2021 were selected as the study subjects. Clinical data of the two fetuses were collected. Conventional G-banded karyotyping and chromosomal microarray analysis (CMA) were carried out for the fetuses and their parents. Prenatal ultrasonography of fetus 1 has revealed absence of nasal bone, ventricular septal defect, persistent left superior vena cava, and mild tricuspid regurgitation. Chromosomal karyotyping was 46,X?,dic r(21;21)(p12q22;q22p12)[41]/45,X?,-21[9]. CMA has revealed a 30.00 Mb quadruplication at 21q11.2q22.3 and a 3.00 Mb deletion at 21q22.3. For fetus 2, ultrasonography has revealed pointed echo of the nasal bone. The fetus was found to have a karyotype of 46,X?,r(21)(p12q22)[83]/45,X?,-21[14]/46,X?,dic r(21;21)(p12q22;q22p12)[3]. CMA has revealed a 5.10 Mb quadruplication at 21q22.12q22.3 and a 2.30 Mb deletion at 21q22.3. The perinatal phenotype of the two fetuses with ring chromosome 21 mosaicisms is related to the duplication of chromosomal segments near the breakpoints of the chromosomal deletions. The combined chromosomal karyotyping and CMA has enabled prenatal diagnosis and genetic counseling for these families.

Thoracoscopic surgery for atrial fibrillation in a patient with persistent left superior vena cava: a case report

BackgroundA persistent left superior vena cava (PLSVC) is an anomaly of the thoracic venous system that flows into the right atrium via an enlarged coronary sinus. When performing pulmonary vein isolation and left atrial appendage closure, the PLSVC can interfere with the procedure. We have performed thoracoscopic surgery on such a patient and would like to share our experience.Case presentationThe patient is a 70-year-old male with a 1-year history of repeated tachycardia with chest discomfort due to paroxysmal atrial fibrillation. Contrast-enhanced computed tomography revealed the presence of a PLSVC that flows into the right atrium. The hepatic vein flows directly into the right atrium, whereas the inferior vena cava enters the thoracic cavity next to the descending aorta and flows into the parazygous vein and PLSVC. We performed thoracoscopic stapler closure of the left atrial appendage and epicardial clamp-isolation of the pulmonary veins and the PLSVC. There was concern that the PLSVC would interfere with the visual field needed to perform the procedure. We carefully removed the adhesions to the surrounding tissue and provided mobility to the PLSVC and expanded it ventrally. As a result, the procedure could be performed safely and without complications.ConclusionsOur results demonstrate that in cases where catheter ablation is difficult for anatomical reasons, thoracoscopic stapler closure of the LAA and epicardial clamp-isolation of pulmonary veins may be a viable option.

Successful cardiac synchronization therapy device upgrade using an active fixation quadripolar pacing lead in a patients with persistent left superior vena cava and absent right superior vena cava.

Successful cardiac synchronization therapy device upgrade using an active fixation quadripolar pacing lead in a patients with persistent left superior vena cava and absent right superior vena cava.

Comparison of free-running whole-heart 5D and 4D flow imaging to standard 2D phase contrast in patients with right-sided congenital heart disease

Abstract Funding Acknowledgements Type of funding sources: None. Background Flow measurements by cardiac magnetic resonance (CMR) are part of a routine assessment in patients with congenital heart disease (CHD). Standard 2D phase contrast (2DPC) sequences, however, require precise prescription of image planes leading to long scan times which could be overcome by 3D-acquisitons covering the entire cardiac anatomy in a single acquisition. Thus, recently introduced accelerated free-breathing 3D whole heart flow sequences promise to simplify CMR exams allowing an easier acquisition and retrospective flow measurements in virtually all vessels. Purpose Comparison of standard 2DPC to an accelerated 4D flow sequence with prospective respiratory navigation (1), and a free-running radial fully self-gated respiratory and cardiac motion-resolved 5D flow sequence (5D flow) (2,3). Methods Patients with right-sided CHD and no intra- or extracardiac shunt underwent a CMR on a 1.5T scanner. 2DPC flow sequences and a 4D flow data set were obtained (1). In addition, a whole-heart free-running 3D radial PC CMR sequence was acquired (2). Using a compressed-sensing-based image reconstruction framework (2,3), 5D flow images were obtained, and the end-expiratory phase was used for analysis. 3D vessel segmentation was based on retrospectively computed phase-contrast angiography images for each 4D and 5D flow datasets. Flow measured in the ascending, descending aorta (AA, DA), main, right and left pulmonary artery (MPA, RPA, LPA) and superior vena cava (SVC) as well as the internal consistency for determination of systemic and pulmonary output were compared between all three sequences by Bland-Altman analyses. Results Twenty CHD patients (age 31±11y, 7 women, tetralogy of Fallot N=7, Ross operation N=10; pulmonary regurgitation, atrial switch and Ebstein’s disease each N=1) were included. Mean peak velocity of MPA/ right ventricle to pulmonary artery conduit was 1.9 (range 0.9; 3.5) m/s. Compared to 2DPC, both 4D and 5D flow moderately underestimated absolute flow with significant lower values for the RPA for 4D flow (Table 1). The bias (i.e. the mean absolute difference) of MPA flow between 2DPC and 4D flow was related to the MPA peak velocity (r2=0.3, p = 0.03) with a similar trend for the comparison of 2DPC vs. 5D flow (r2=0.142, p = 0.141). The comparison of the internal consistency for determination of systemic and pulmonary output showed similar results for 2DPC and 5D flow and a slightly lower agreement for the 4D flow sequence (Table 2). Conclusions In this preliminary study, 4D and 5D flow provide results comparable to 2DPC, however, both sequences showed a trend towards lower absolute flow values. Complex flow patterns due to the right-sided pathologies appear to have an impact on the difference observed between sequences as shown for the MPA. The internal consistency of flow quantification was similar for the 2DPC and 5D flow sequences. The presented observations are currently being evaluated in a larger study.

A missense variant at the RAC1-PAK1 binding site of RAC1 inactivates downstream signaling in VACTERL association

RAC1 at 7p22.1 encodes a RAC family small GTPase that regulates actin cytoskeleton organization and intracellular signaling pathways. Pathogenic RAC1 variants result in developmental delay and multiple anomalies. Here, exome sequencing identified a rare de novo RAC1 variant [NM_018890.4:c.118T > C p.(Tyr40His)] in a male patient. Fetal ultrasonography indicated the patient to have multiple anomalies, including persistent left superior vena cava, total anomalous pulmonary venous return, esophageal atresia, scoliosis, and right-hand polydactyly. After birth, craniofacial dysmorphism and esophagobronchial fistula were confirmed and VACTERL association was suspected. One day after birth, the patient died of respiratory failure caused by tracheal aplasia type III. The molecular mechanisms of pathogenic RAC1 variants remain largely unclear; therefore, we biochemically examined the pathophysiological significance of RAC1-p.Tyr40His by focusing on the best characterized downstream effector of RAC1, PAK1, which activates Hedgehog signaling. RAC1-p.Tyr40His interacted minimally with PAK1, and did not enable PAK1 activation. Variants in the RAC1 Switch II region consistently activate downstream signals, whereas the p.Tyr40His variant at the RAC1-PAK1 binding site and adjacent to the Switch I region may deactivate the signals. It is important to accumulate data from individuals with different RAC1 variants to gain a full understanding of their varied clinical presentations.

Electrophysiological responses of the left atrial appendage during pulsed-field electrical isolation utilizing a novel device in a canine model.

The electrophysiological responses of the left atrial appendage (LAA) during pulsed-field electrical isolation have not been established. This study aims to investigate the electrical responses of the LAA during pulsed-field electrical isolation using a novel device and their relations to acute isolation success. Six canines were enrolled. The E-SeaLA™ device, which is able to perform LAA occlusion and ablation simultaneously, was deployed into the LAA ostium. LAA potentials (LAAp) were mapped via a mapping catheter, and the LAAp recovery time (LAAp RT, the time between the last pulsed spike and the first recovered LAAp) was measured after pulsed-train delivery. The initial pulse index (PI, corelated to pulsed-field intensity) was adjusted during the ablation procedure until LAAEI was achieved. Acute LAA electrical isolation (LAAEI) success was defined as LAAp disappearance or exit and entrance conduction block, confirmed through a drug test and a 60-minute waiting period. All canines achieved successful LAA occlusion without peri-device leaks. Acute LAA electrical isolation (LAAEI) was achieved in five out of six canines (5/6, 83.3%). Very late LAAp recurrence (LAAp RT > 600 s) was observed during PFA. Early recurrence (LAAp RT < 30 s) was observed in two canines (2/6, 33.3%) post-PFA. Intermediate recurrence (LAAp RT ~ 120 s) was observed in three canines (3/6, 50%) post-PFA. The two canines with intermediate recurrence achieved LAAEI with higher PI ablations. The one canine with early LAAp recurrence had a peri-device leak and achieved LAAEI by the same PI after replacing with a larger size device and eliminating the peri-device leak. Another canine with early recurrence (1/6, 16.7%) failed to achieve LAAEI due to epicardial connection with persistent left superior vena cava. No coronary spasm, stenosis or other complications were observed. These results suggest that with proper device-tissue contact and pulse intensity, LAAEI can be achieved using this novel device without serious complications. The LAAp RT patterns observed in this study could inform and guide the adjustment of the ablation strategy.

Acute success, stability and safety of left bundle branch area pacing with steerable catheter and stylet-driven leads: A single center experience

Abstract Funding Acknowledgements Type of funding sources: None. Background/Introduction Right ventricular apical pacing is associated with adverse outcomes and there is an increasing preference to perform conduction system pacing as it allows for more physiological left ventricular activation. His-bundle pacing is known to be technically challenging and results in higher pacing thresholds and increased rates of lead dislodgement. Left bundle branch area pacing (LBBAP) is an emerging alternative form of conduction system pacing. Purpose We aim to study the acute success rates, short-term stability and safety using steerable catheter and stylet-driven (SD) leads for the purpose of LBBAP. Methods 40 consecutive patients who underwent LBBAP with steerable catheter and SD leads in our center from August 2021 to November 2022 were included in this series. Patients’ demographics, pacing indications, baseline QRS morphologies and duration and left ventricular ejection fraction (LVEF) were analysed. Acute success was defined as achieving stimulation to LV activation time (Stim-LVAT) ≤75ms or incomplete right bundle branch paced morphology in V1 [1, 2]. We also reported any left bundle branch (LBB) potential (if present) and the V6-V1 interpeak interval. All lead parameters and complications in the immediate (1 day) and short-term (1 week and 3-6 months) timeframe were evaluated. Results 40 patients' age (mean 72.75), gender (male 52.5%), body mass index (mean 24.15) and LVEF (mean 52.75%) were analysed. Pacing indications included sinus nodal dysfunction (25%), atrioventricular block (70%), heart failure with failed cardiac resynchronisation therapy (CRT) (2.5%) and atrial fibrillation (AF) requiring atrioventricular node ablation (2.5%). We achieved an acute success rate of 87.5% (5% with left ventricular septal pacing, 5% converted to conventional right ventricular septal pacing, and 2.5% converted to CRT). Reasons for failure to achieve successful LBBAP include persistent left superior vena cava, high pacing thresholds or inability to burrow lead into the septum for acceptable V1 morphology and Stim-LVAT due to resistance encountered during turning of the lead. 51.43% patients of the successful LBBAP patients had LBB potential present and/or interpeak interval &amp;gt;33ms [3]. Immediate and short-term lead parameters were stable and acceptable in all cases. There were no complications (such as lead dislodgement, rise in lead impedance or threshold) reported during the acute and short-term follow-up. Conclusion LBBAP is successful in 87.5% of our cases with use of steerable catheter deploying stylet-driven leads and is proven to be a safe and feasible method for conduction system pacing. Incremental experience with the delivery tools will further improve successful implantation. Longer term follow-up of these patients is needed to determine the long-term safety and stability of LBBAP using steerable catheter and stylet-driven leads.

Morphologic classification of tracheobronchial arborization in children with congenital tracheobronchial stenosis and the associated cardiovascular defects.

We sought to classify patients with congenital tracheal stenosis (CTS) according to tracheobronchial morphology and determine anatomic features associated with tracheobronchial anomalies (TBAs) and concurrent cardiovascular defects (CVDs). We enrolled 254 patients who underwent tracheoplasty between November 1, 2009 and December 30, 2018. The anatomic features of the tracheobronchial tree and cardiovascular system were abstracted from bronchoscopy, echocardiography, computerized tomography, and operative reports. Four types of tracheobronchial morphology were identified: Type-1, which included normal tracheobronchial arborization (Type-1A, n = 29) and tracheal bronchus (Type-1B, n = 22); Type-2 (tracheal trifurcation; n = 49), and Type-3 (typical bridging bronchus; n = 47). Type-4 (bronchus with an untypical bridging pattern) was divided into Type-4A (involving bronchial diverticulum; n = 52) and Type-4B (absent bronchus; n = 55). Carinal compression and tracheomalacia were significantly more frequent in Type-4 patients than in the other patients (P < 0.01). CVDs were common in patients with CTS, especially in patients with Type-3 and Type-4 (P < 0.01). Persistent left superior vena cava was most common among patients with Type-3 (P < 0.01), and pulmonary artery sling was most frequent among those with Type-4 (P < 0.01). Outflow tract defects were most likely to occur in Type-1B. Early mortality was detected in 12.2% of all patients, and young age (P = 0.02), operation in the early era (P < 0.01), and bronchial stenosis (P = 0.03) were proven to be risk factors. We demonstrated a useful morphological classification for CTS. Bridging bronchus was most closely linked with vascular anomalies, while tracheal bronchus was frequently associated with outflow tract defects. These results may provide a clue to CTS pathogenesis.

P146 PERIPHERALLY INSERTED CENTRAL VENOUS CATHETER AND PERSISTENT LEFT SUPERIOR VENA CAVA: WHAT SHOULD WE KNOW?

Abstract Peripherally inserted central catheters (PICCs) are widely used medical devices to provide medium to long–term infusion treatment and therapy. PICC placement is contraindicated in cases of deep–vein thrombosis, end–stage renal disease or if deep venous access is compromised. Among the possible complications there are some related to the interventional procedure (e.g. accidental puncture of an arterial vessel, injury to peripheral nerves, misplacement, arrhythmias, haematoma) and others related to the post–implantation phase (e.g. thrombosis, infection, gas emboli, phlebitis). One of the possible intra–procedural complications is the occasional finding of a persistent left superior vena cava (PLSVC). PLSVC is an anatomical variant present in at least 0.5% of the general population and its occurrence during interventional procedures is not uncommon. Clinical case description An 82–year–old woman was admitted to our Institute following a diagnosis of herpetic encephalitis (HSV1). She had a history of hypothyroidism undergoing substitution treatment. Cause the poor peripheral venous patrimony and the need of infusion therapy with acyclovir, levetiracetam and ceftriaxone, the indication for PICC implantation was given. After antibiotic prophylaxis and sterile field preparation, the procedure was performed with ultrasound–guided Seldinger technique by puncturing the left basilic vein. A successive X–ray showed the PICC running unusually parallel to the right sternum (Fig. 1). The echoscopy with bubble test allowed to visualize the agitated saline solution in the right atrium. In view of the suspected venous abnormality, the PICC was removed and a single–lumen MiniMidline 4F of 11 cm length was placed in the right basilic vein (4 mm). A subsequent chest CT scan visualised the PLSVC and its intrathoracic course, the presence of the right superior vena cava was also observed (Fig. 2). The PLSVC is an anatomical variant encountered during interventional procedures involving peripherally inserted central venous catheters. It is important to recognise this variant to avoid possible procedural and/or post–procedural related surgical complications.

P32 PERSISTENT ISOLATED LEFT SUPERIOR VENA CAVA ASSOCIATED WITH BICUSPID AORTIC VALVE

Abstract Persistent left superior vena cava (VCSSP) is the most frequent systemic venous return anomaly. It often occurs during right heart catheterization (0.1%) and is associated with right superior vena cava aplasia in 10 to 33%. It can lead to the development of a left superior venous system mirroring the normal right return. It runs between the pulmonary veins and the left auricle, to join the coronary sinus. Sometimes the coronary sinus does not communicate directly with the right atrium but drains into the VCSS. An increased incidence of arrhythmias has also been reported in the presence of venous drainage abnormalities. Its discovery has implications as it can create difficulties in the insertion of central venous catheters, cardiac surgery, thoracic and PMK implantation.VCSSP in the absence of the right superior vena cava (VCSD) is a rare congenital anomaly. Clinical case An 18–year–old soccer player came to our observation for an episode of presyncope and palpitations during a soccer match. The ECG showed sinus rhythm and incomplete right bundle branch block. The echocardiogram showed a bicuspid aortic valve and significant dilatation of the coronary sinus, with suspicion of persistence of the left superior vena cava. Cardiac MRI showed an isolated persistent left superior vena cava along the left mediastinum and extending it connected with the coronary sinus, which in turn drained into the right atrium. There was no evidence of LGE in the late sequences. Discussion VCSSP does not constitute a hemodynamic problem if isolated. The presence of VCSSP in the absence of right superior vena cava (VCSD) is in itself an occurrence rarely described in the literature. The anomalies most frequently associated with the presence of a VCSSP are the Atrial septal defect of the sinus venosus type and tetralogy of Fallot. Rare cases of association with aortic valve bicuspid have also been reported.In patients with VCSSP and absence of VCSD, the coexistence of impulse formation and impulse conduction disorders associated with histological alterations such as fragmentation and stretching of the specific conduction tissue and of the atrioventricular node has been described. The abnormal development can also induce sinus node alterations resulting in sinus dysfunction. In our case, no conduction anomalies or arrhythmias were described

Hemodialysis through persistent left superior vena cava. Should it be used?

Background To describe a case of hemodialysis done through persistent left superior vena cava, identified incidentally after a left jugular central venous dialysis catheter insertion, and to discuss its feasibility. Case Summary Single case: A 66-year-old woman was admitted to the ICU with a diagnosis of septic shock, severe pneumonia, and acute renal failure. Hemodialysis was required for acute renal insufficiency. Persistent left superior vena cava (PLSVC) was detected on Chest x-ray after a left jugular central venous dialysis catheter placement. Hemodialysis was uneventful. Using a permanent dialysis catheter placed later through the PLSVC was less efficient. Although no complications were seen during hemodialysis, it was technically difficult (with high pressure in access and low blood flow rate). Conclusion Hemodialysis through PLSVC should remain an exceptional and short-term therapeutic alternative in dialysis patients.

Evaluating Types of TAPVR on Echocardiography and CT Angiography in Paediatric Patients Admitted in Tertiary Care Hospital: A Comparative Study

Objective: To evaluate the types of TAPVR on Echocardiography and CT Angiography in Paediatric Patients Study design: A comparative study Place and Duration: Pediatric cardiology department and CT Angiography department of the National Institute of Cardiovascular Diseases (NICVD) Karachi from January 2019 to December 2021 Methodology: Patients who have TAPVR confirmed by CT angiography and detected by echocardiography were included in the research. Cases having anomalies in the systemic veins were eliminated. Demographic variables (age, gender, weight, etc.), echocardiographic results (such as type of TAPVR, obstructive and non-obstructive), and CT angiography findings were collected for the study using a preset structured proforma. We evaluated the diagnostic disparity between the two modalities. Results: In the present study there were 107 patients, 67.3% were male gender, 56.1% with age less than 6 months, the median age was 6 months, median weight was 4.5 kg. On echocardiography, there were 83.2% non-obstructive, 47.7% supracardiac and 36.4% cardiac TAPVR. On CT angiography, there were 66.4% were non-obstructive, 53.3% supracardiac and 23.4% cardiac TAPVR. Of the associated cardiac diseases, in common 86.9% were found with atrial septal defect, 13.1% were persistent left superior vena cava, 12.1% were patent ductus arteriosus, 8.4% were a ventricular septal defect, 6.5% were of pulmonary atresia, and 3.7% were complete endocardial cushion defect. Conclusion: As compared to echocardiography, CT angiography is more reliable for the detection of obstructive and mixed types of TAPVR. Detection of the supracardiac type of TAPVR is also almost the same as on echocardiography and CT angiography. As compared to CT angiography, echocardiography over diagnoses the non-obstructive type of TAPVR. CT angiogram is also useful in detecting other associated lesions such as heterotaxy, abnormal coronaries, presence of bilateral superior vena cava and coronary sinus. Keywords: TAVPR, echocardiography, CT angiography, cardiac disorders

Genetic analysis of a fetus with de novo 46,X,der(X)t(X;Y)(q26;q11)

To carry out prenatal genetic testing for a fetus with de novo 46,X,der(X)t(X;Y)(q26;q11). A pregnant woman who had visited the Birth Health Clinic of Lianyungang Maternal and Child Health Care Hospital on May 22, 2021 was selected as the study subject. Clinical data of the woman was collected. Peripheral blood samples of the woman and her husband and umbilical cord blood of the fetus were collected and subjected to conventional G-banded chromosomal karyotyping analysis. Fetal DNA was also extracted from amniotic fluid sample and subjected to chromosomal microarray analysis (CMA). For the pregnant women, ultrasonography at 25th gestational week had revealed permanent left superior vena cava and mild mitral and tricuspid regurgitation. G-banded karyotyping analysis showed that the pter-q11 segment of the fetal Y chromosome was connected to the Xq26 of the X chromosome, suggesting a Xq-Yq reciprocal translocation. No obvious chromosomal abnormality was found in the pregnant woman and her husband. The CMA results showed that there was approximately 21 Mb loss of heterozygosity at the end of the long arm of the fetal X chromosome [arr [hg19] Xq26.3q28(133912218_154941869)×1], and 42 Mb duplication at the end of the long arm of the Y chromosome [arr [hg19] Yq11.221qter(17405918_59032809)×1]. Combined with the search results of DGV, OMIM, DECIPHER, ClinGen and PubMed databases, and based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the deletion of arr[hg19] Xq26.3q28(133912218_154941869)×1 region was rated as pathogenic, and the duplication of arr[hg19] Yq11.221qter(17405918_59032809)×1 region was rated as variant of uncertain significance. The Xq-Yq reciprocal translocation probably underlay the ultrasonographic anomalies in this fetus, and may lead to premature ovarian insufficiency and developmental delay after birth. Combined G-banded karyotyping analysis and CMA can determine the type and origin of fetal chromosomal structural abnormalities as well as distinguish balanced and unbalanced translocations, which has important reference value for the ongoing pregnancy.

Cardiovascular Manifestations of Turner Syndrome: Phenotypic Differences Between Karyotype Subtypes.

Turner syndrome (TS) is a genetic disorder presenting in phenotypic females with total or partial monosomy of the X chromosome. Cardiovascular abnormalities are common, including congenital heart defects (CHD) and aortic dilation. Although mosaic TS is suspected to have less severe phenotype as compared to non-mosaic TS, differences in cardiovascular manifestations between karyotypes are not well studied. This is a single-center retrospective cohort study including patients with TS seen from 2000 to 2022. Demographic data, chromosomal analysis, and imaging were reviewed. Karyotypes were categorized as monosomy X (45X), 45X mosaicism, isochromosome Xq, partial X deletions, ring X(r(X)), TS with Y material, and others. Prevalence of CHD and aortic dilation were compared between monosomy X and other subtypes using Pearson's chi-square test and Welch two-sample t-test. We included 182 TS patients with median age 18 (range 4-33) years. CHD was more common in monosomy X as compared with others (61.4%vs.26.8%, p < 0.001), including bicuspid aortic valve (44.3%vs.16.1%, p < 0.001), partial anomalous pulmonary venous return (12.9%vs.2.7%, p = 0.023), persistent left superior vena cava (12.9%vs.1.8%, p = 0.008), and coarctation of the aorta (20.0%vs.4.5%, p = 0.003). Cardiac surgery (24.3%vs.8.9%, p = 0.017) was more prevalent in the monosomy X group. There was no statistically significant difference for presence of aortic dilation (7.1% vs 1.8%, p = 0.187). Although CHD and need for cardiac surgery are more common in TS with monosomy X as compared to others, all TS subtypes may have similar risk of developing aortic dilation. All TS patients should have similar cardiovascular surveillance testing to monitor for aortic dilation.

Persistent left superior vena cava without right superior vena cava during fetal life.

Enlarged coronary sinus detected during cardiac examination in the prenatal period is the first finding that raises suspicion for persistent left superior vena cava. In this report, a patient was presented who was referred with the prediagnosis of cor triatriatum sinister in the antenatal period and diagnosed with isolated persistent left superior vena cava (SVC).

Unusual Course of a Pulmonary Artery Catheter Due to Absence of Right Superior Vena Cava.

The persistent left superior vena cava may complicate the placement of vascular access. It rarely occurs with an absence of the right superior vena cava. We present a chest X-ray of a patient with this rare anomaly that was demonstrated incidentally with an unusual course of a pulmonary artery catheter course.

Total Anomalous Pulmonary Venous Connection with Persistent Left Superior Vena Cava: A Retrospective Surgical Series

Introduction: Total anomalous pulmonary venous connection (TAPVC) is a common cyanotic congenital heart disease seen in developing countries at tertiary referral centers. Association with persistent left superior vena cava (LSVC) without innominate vein (H-connection) is an extremely rare condition which makes the surgical correction extremely challenging. Materials and Methods: This was a retrospective case record review of 18 patients with TAPVC in the presence of LSVC without innominate vein (without H-connection) at our institution from January 2007 to February 2021. We detail our experience of our modified surgical technique for this complex anatomy using various modifications for each type of TAPVC with LSVC in the absence of innominate vein. Results: Out of 18 patients of TAPVC with LSVC, 17 patients survived and are being followed up regularly. There was one mortality (5.5%) in a 5-month-old infant with double-outlet right ventricle with ventricular septal defect with severe pulmonary arterial hypertension with infracardiac TAPVC who died in intensive care unit on the 5th postoperative day. Conclusion: In our experience, the modified surgical technique for treating this complex variant of TAPVC is especially useful for favorable long-term outcomes with minimal incidence of recurrent pulmonary venous obstruction.

Successful implantation of dual-chamber permanent pacemaker in case of persistent left superior vena cava with the absence of right superior vena cava

ABSTRACT Persistent left superior vena cava (PLSVC), a rare congenital abnormality of the venous system, often goes unnoticed. Typically, it is identified incidentally while performing certain interventional procedures. It may manifest as sick sinus syndrome (SSS) or third-degree atrioventricular block, necessitating pacemaker implantation. This placement can be challenging since the dilated coronary sinus (CS) complicates locating the ventricular lead in certain circumstances. Here, the presented case focuses on a 55-year-old female presenting with SSS after complaining of presyncope, chest pain, and dizziness. The decision to implant a dual-chamber pacemaker was approved, but technical complications suggested a PLSVC with an absent right superior vena cava throughout the procedure. The particularity of this case was that, despite the anatomical difficulties, it was possible to cross the ventricular lead into the CS using a semicircular stylet.

PO-04-081 ISOLATION OF PERSISTENT LEFT SIDED SUPERIOR VENA CAVA USING PULSED FIELD ABLATION

Pulmonary vein foci account for more than 90% of triggers for atrial fibrillation, most commonly treated with complete pulmonary vein isolation. Non–pulmonary vein triggers are the drivers of atrial fibrillation in a subgroup of patients. One such trigger is a persistent left superior vena cava (SVC), which may contain remnant muscular and pacemaker tissue carried over from embryonic life. However, reported complications of radiofrequency ablation of this structure are significant, including vein stenosis, tamponade and phrenic nerve injury. Pulsed field ablation is a promising new technology that may be uniquely suited to avoid such a complications. This case illustrates the first known application of pulsed field ablation of a left sided SVC. N/A The patient is a fifty-two year old male with a history of coronary artery disease and persistent atrial fibrillation refractory to medical therapy including rate and rhythm control strategies. He is status post multiple cardioversions with restoration to normal sinus rhythm for a relatively short period of time. The patient underwent an ablation procedure at which time it was discovered that he had an isolated persistent left sided SVC. Pulmonary vein isolation was performed using a combined radiofrequency and pulsed field ablation lattice tip catheter (Affera inc., Watertown, MA). Accordingly to study protocol, lesions were placed using radiofrequency anteriorly and pulsed field lesions posteriorly in the left atrium around the pulmonary veins resulting in complete isolation. The patient also developed a counterclockwise typical atrial flutter which was ablated. Given the propensity for triggers from the SVC, pulsed field ablation was performed by creating a circumferential lesion set superiorly beyond the left superior pulmonary vein region and inferiorly near the mid coronary sinus below the left inferior pulmonary vein. A linear lesion set connecting these two regions was also performed along the atrial portion of the coronary sinus, with subsequent confirmation of exit block and elimination of all local electrograms. In patients with persistent left SVC, pulsed field ablation is feasible without the risk of phrenic nerve injury or tamponade from excessive contact force. Further studies are necessary to examine whether the complications associated with LSVC isolation can be minimized.

PO-04-086 IMPLANTATION OF A LEADLESS PACEMAKER FOR HYBRID DUAL CHAMBER PACING IN A PATIENT WITH A FAILING RIGHT VENTRICULAR LEAD AND HIGH SURGICAL RISK: A CASE REPORT

Mechanical atrial sensing in Micra AV (Medtronic) leadless pacemakers facilitates atrioventricular (AV) synchrony in patients with AV block despite single chamber pacing. Little data is available on the efficacy of Micra AV atrial tracking in patients with concomitant sinus node dysfunction requiring atrial pacing. We present a case that demonstrates the efficacy and utility of Micra AV pacing in the context of transvenous atrial pacing. N/A A 49-year-old woman with complete heart block, sinus node dysfunction, right-sided dual-chamber pacemaker, and subsequent right atrial (RA) lead dysfunction treated with RA lead capping and new implantation, presented to our institution for pacemaker management. Device interrogation revealed rising RV lead impedances and pacing thresholds, for which lead extraction and re-implantation was recommended. Pre-operative imaging revealed partial flow obstruction in the right subclavian vein, an interrupted inferior vena cava, and a persistent left superior vena cava (SVC) with no right SVC connection. As urgent intra-operative cardiopulmonary bypass in the event of vascular rupture would prove difficult, the patient was deemed not a candidate for lead extraction. In an effort to prevent SVC syndrome, the decision was made to implant a Micra AV leadless pacemaker and program the old RV lead to off. The patient’s anatomy precluded a conventional femoral venous approach to Micra implantation, so implantation was achieved via the right internal jugular vein. The procedure was successful without intraprocedural complication. To allow for atrial pacing and to promote AV synchrony, the dual chamber pacemaker was programmed to AAIR 70/100 bpm with the leadless pacemaker programmed to VDD 50/105 bpm. Quarterly device interrogations in the 12 months following Micra implantation demonstrated 77-92% RA pacing and 99% RV pacing with atrial tracking from the Micra device at 76-83% with optimized atrial sensing. This case exemplifies the clinical scenario in which hybrid dual chamber pacing may be indicated. The case also highlights the atrial tracking capability of the Micra AV leadless pacemaker in the setting of an AAIR transvenous pacemaker, ultimately demonstrating the feasibility and potential application of hybrid dual chamber pacing in patients in need of RV lead revision but with prohibitive surgical risk or limited venous access.