Ischemic Heart Disease with In-Stent Re-Stenosis with Complete Heart Block and Isolated Persistent Left Superior Vena Cava – Rare Case Report with Challenges and Clinical Implications

ABSTRACT

Isolated persistent left superior vena cava (PLSVC) is a very rare congenital thoracic venous system anomaly and is commonly an incidental finding, usually detected during central venous access, cardiac catheterization, or cardiothoracic surgeries. This is a rare case report wherein the patient is a known case of ischemic heart disease with s/p percutaneous transluminal coronary angioplasty (PTCA) with a stent to left anterior descending (LAD) artery with in-stent re-stenosis presented with complete heart block and had an unanticipated discovery of isolated PLSVC on facing difficulty during the transvenous approach of permanent pacemaker implantation (PPI). In this case report, we inspect the challenges associated with and various clinical implications of isolated PLSVC.

INTRODUCTION

“Isolated PLSVC,” implies the absence of the right superior vena cava (RSVC) and the presence of only the left-sided superior vena cava (LSVC).[1] Embryological defect involving failure of the left anterior cardinal vein to degenerate results in PLSVC.[2] Patients with PLSVC are asymptomatic and are diagnosed incidentally. Arrhythmias and conduction abnormalities are common in the presence of PLSVC due to anatomical and architectural abnormalities of the Sinoatrial (SA) node and conduction tissues due to dilation of the coronary sinus.[3] Most common approach for PPI is a transvenous route; however, it is very challenging in patients with isolated PLSVC because of the complex anatomy with very sparse literature.[4] The definitive approach for PPI is epicardial implantation in patients with difficult access through a transvenous approach for lead placement.[5]

CASE REPORT

A 54-year-old male patient, chronic smoker, with type 2 diabetes mellitus, known case of ischemic heart disease with s/p PTCA with stent to LAD presented with low heart rate and NYHA grade IV shortness of breath, evaluated to have complete heart block, posted for transvenous PPI in the cardiac catheterization laboratory, having faced difficulty during the transvenous approach of PPI due to abnormal course of the venous system, patient was transiently put on temporary pacemaker implantation (TPI), with coronary angiogram findings of ISR (in-stent re-stenosis) and venogram findings of persistent LSVC draining into coronary sinus and absent RSVC. Patient was therefore scheduled for CABG + PPI. An ideal case for an epicardial approach for PPI. In OR, all standard monitors were connected, and baseline vital parameters of the patient were recorded. Patient was pre-oxygenated and general anesthesia induced. For invasive monitoring, 20 G left radial artery cannulation was performed. The patient has agenesis RSVC, with isolated PLSVC, and for this reason, the central line is secured with 8.5 Fr, 16.5 cm, and 4-lumen ports catheter to the left SVC. Off-pump CABG was performed, followed by the placement of a permanent pacemaker epicardial lead to the ventricle, and a pulse generator was placed in the left sub-costal region. Intraoperative and post-operative courses were uneventful.

DISCUSSION

Isolated PLSVC is a very rare congenital thoracic venous system anomaly, an incidental finding; literature regarding the relative frequency of PLSVC is sparse; however, it is known to be prevalent among 0.3%-0.5% of the general healthy population.[6,7,8,9,10,11,12,13,14,15,16,17,18,19] Isolated PLSVC occurs in only 10%–20% of PLSVC cases.[7] Isolated PLSVC is usually associated with other congenital cardiac anomalies with a prevalence range of 0.09% to 0.13%.[8] Common congenital heart diseases found in association with isolated PLSVC include ventricular septal defect, atrial septal defect, endocardial cushion defects, coronary sinus ostial atresia, coarctation of the aorta, cortriatriatum, and tetralogy of Fallot.[1] In our case, the patient did not have any associated congenital cardiac anomalies.

During the 8^th week of gestation, the caudal part of the right anterior cardinal vein, together with the common cardinal vein, forms the RSVC. Generally, the left common cardinal vein and the caudal part of the left anterior cardinal vein will regress to become the “ligament of Marshall,” failure to regress results in PLSVC. In 80% to 90% of cases, PLSVC connects to the right atrium via the coronary sinus with no significant hemodynamic changes. In the remainder of the cases, it may drain into the left atrium.[9] In our case, intra-operative findings concur with pre-operative diagnosis.

PLSVC poses no problem to a general healthy population. Usually, a fortuitous finding occurs during cardiovascular imaging cardiac pacemaker implantation.[3] PLSVC has various practical implications.

It is challenging for central venous access due to the complex course of PLSVC. Any excessive manipulation can result in hemodynamic instability, arrhythmias, perforation of the heart, and cardiac tamponade.[1,9] Post-procedure imaging can reveal the abnormal anatomical venous course.

Placement of transvenous PPI, implantable cardioverter defibrillator, and Swan-Ganz catheter can be troublesome and coupled with technical difficulty due to complex anatomy and overcome by experienced operators and positioning leads into appropriate anatomical positions using long guide sheaths and/or customized stylet shapes.[4] Despite all efforts and specialized techniques, it becomes difficult for PPI placement in certain cases, curtailing a temporary pacing lead insertion and planning for an alternative method of PPI. Available approaches for PPI in patients with isolated PLSVC include: (1) left subclavian vein approach, (2) inferior vena cava (IVC) approach, (3) micra transcatheter pacing system (leadless pacemaker) fully self-contained, miniaturized pacemaker, and (4) epicardial pacemaker.[10] In our case, there was a technical difficulty in the transvenous approach for PPI. Therefore, the patient was put on TPI and planned for an elective surgical epicardial PPI.

Retrograde cardioplegia offering myocardial protection is a common practice for cardiac surgeries found to be ineffective in cases with isolated PLSVC. It requires separate cannulation and clamping of PLSVC to prevent retrograde flow. There is a possibility of stealing cardioplegic fluid through a branch of the accessory hemiazygos vein even after clamping PLSVC resulting in failure of the cardioplegic effect.[11] In our case, an off-pump CABG procedure was performed, eliminating the above complications.

The association between PLSVC and abnormal rhythm patterns may be more than chance, as most case reports with abnormalities of cardiac rhythm or conduction were identified to have PLSVC.[12] Abnormal development of the right horn of the sinus venous (origin of SA node) and right superior cardinal vein (origin of RSVC) may result in SA node dysfunction. Dilation of the coronary sinus (CS) causes a stretch of atrio-ventricular (AV) nodal tissue, resulting in AV nodal re-entrant tachycardia.[1,13] In our case, the patient is not associated with arrhythmias due to PLSVC.

Persistent LSVC and associated extra-cardiac abnormalities include increased nuchal translucency, single umbilical artery, agenesis, or aberrant drainage of ductus venosus, hemivertebrae, and esophageal atresia. The most common anomaly was esophageal atresia. The various syndromes associated are VACTERL association (vertebral defects, anal atresia, cardiac defects, tracheoesophageal fistula, renal and limbs abnormalities), CHARGE association (coloboma, heart defects, atresia of choanae, retardation, genital and ear anomalies) and X-linked Opitz G/BBB (X-OS syndrome), Turner’s, Trisomy 21, 22q11.2 microdeletion. In isolated PLSVC, the risk of chromosomal abnormality could be up to 7% [Figures 1-4].[14]

Figure 1.

White arrows indicating course of contrast injected into Right Subclavian Vein traversing Innominate Vein and Persistent Left Superior Vena Cava

Figure 4.

Mid-esophageal view on Trans-esophageal Echocardiograph. Left Atrium (LA), Left Ventricle (LV)

Figure 2.

Surgical Field showing Left Superior Vena Cava with heart tilted towards right side

Figure 3.

Post-operative Chest X-ray

In approximately 10% to 20% of cases of PLSVC, the PLSVC can drain via the left atrium, either through an unroofed CS or in a straight-line fashion, into the roof of the left atrium or through the left superior pulmonary vein. This particular venous drainage pattern of PLSVC causes a significant risk of paradoxical embolic complications.[7]

The standard technique for the diagnosis is echocardiography, either transthoracic or transesophageal. TEE shows a large CS with a normal CS diameter <1 cm, the mid-esophageal view shows PLSVC near the LA appendage and left pulmonary vein, and the bicaval view shows the absence of RSVC.[1] Prenatal diagnosis with Ultrasound examination of the fetal heart can help diagnose isolated PLSVC and the three-vessel view shows abnormally arranged from right to left, aortic arch, arterial duct, and persistent LSVC. The clinical implication of prenatal diagnosis of PLSVC is to know the association with cardiac and extra-cardiac defects for an overall patient prognosis assessment.[14,15]

CONCLUSION

Isolated PLSVC, an infrequent venous anomalous condition, an incidental finding, has an intrinsic association with other congenital cardiac anomalies, and unusual anatomical course ensued identified by various diagnostic modalities available. Clinicians must have preliminary knowledge about various clinical implications of isolated PLSVC and an organized strategy for case management to obviate intricacies associated with the condition.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.