The presence of persistent left superior vena cava (PLSVC) “is the most common congenital anomaly of the SVC system.”^1,4 Although considered a common anomaly, it is a rare but non-debilitating condition. A patient may not present any appreciable symptoms to the clinician if there are not any additional associated abnormalities. The presence of PLSVC is usually discovered during the cannulation of the superior vena cava for placement of a Swan Ganz catheter, central line or a pacemaker/ICD lead.

Review of Literature
       Reports of the existence of PLSVC have been documented and submitted to various respected medical publications. In a 2003 review of literature, Rajit Pahwa and Anand Kumar reported that PLSVC occurs “0.3% in individuals with a normal heart and 4.5% in individuals with congenital heart disease.”² This anomaly is considered to originate during the embryonic stage. During this period of development, “blood is normally drained from the upper body by two cardinal veins”, the “left anterior cardinal vein would drain blood from the left cephalic area. If the left cardinal vein does not regress normally,”³ the result is a persistent left superior vena cava (LSVC). The most common finding is that “the LSVC drains via the coronary sinus into the right atrium.”³ There are, however, several documented variations of this anomaly that will not be discussed here but can be viewed online at various web sites.
       A review of medical literature revealed several examples of the same anomaly as discussed in this report. One such example was concerned with the proper placement of a Hickman catheter¹ due to its eccentric position under x-ray. Three articles reported on the task of manipulating a pacemaker lead via the PLSVC through the CS and right atrium to the right ventricle.^5,6,7 Two other articles reported the placement of ICD leads by way of the same type of anomaly.^8,9 The task of positioning a pacing or an ICD lead with this anomaly is challenging and formidable.
       The earliest device implant procedure article involving a PLSVC was reported January 1995.⁸ Dr. Ross Brooks et al. reported that the ICD implant procedure and recovery were uneventful. The only difficulty was due to the unusual entry into the right atrium, making it more difficult to cross the tricuspid valve. The latest implant procedure article with PLSVC was dated April 7, 2004, in which two cases were reported involving the placement of pacemaker leads.
       The difficulty of manipulating leads in 1995, let alone an ICD lead, gives credibility to any physician that would successfully complete a similar procedure.

Case Report
       In April 2005, a 50-year-old female with a history of chronic atrial fibrillation was admitted to Oklahoma Heart Hospital for a single-lead pacemaker implant to the right ventricular apex.
       The patient was transported to the EP lab for a routine pacemaker lead placement. As standard procedural care, the patient’s blood pressure, heart rate, respirations and oxygen saturation were monitored throughout the case. The patient was given oxygen by nasal cannula. A staff RN provided continual monitoring of conscious sedation and vital signs.
       The left subclavian area was prepped and draped in a standard sterile manner. After subcutaneous infiltration of 2% lidocaine was accomplished, a #10 blade scalpel was used to open an area of the tissue for the procedure. An adequate pocket was obtained for the intended device. Using the Seldinger technique, a hollow needle access to the left subclavian vein was performed. Several attempts were made to access the vein. Because the subclavian artery was in such close proximity to the left subclavian vein, contrast was injected through an existing IV in the left arm to document the subclavian vein patency. A fluoroscopy image was recorded (Figure 1).

Figure 1.

Contrast in the left brachial vein can be seen in the left subclavian vein and left superior vena cava.

       After determining that the left subclavian vein was patent, access was achieved, allowing a standard pacemaker guidewire to be inserted. Due to the unusual course the wire presented as it advanced through the left subclavian vein toward the right atrium, a second IV was placed in the patient’s right arm and contrast was injected through it.

Figure 2.

Contrast injected into the right subclavian vein can be seen crossing the mid-sternum into the left superior vena cava. The thin line in the left subclavian and left superior vena cava is the guidewire that curves out of the picture. The tip can be seen just at the bottom and right side of the heart’s image.

       While using fluoroscopy, contrast was documented flowing through the right subclavian vein across the chest and into the left superior vena cava (Figure 2).

Figure 3.

Both right and left subclavian empty into the persistent left subclavian vena cava. The PLSVA then connects to the coronary sinus, which empties into the right atrium. Copyright protected material used with permission of the authors and the University of Iowa’s Virtual Hospital, www.vh.org.

       The persistent left superior vena cava anatomical anomaly is best illustrated by Bedart in his 1892 drawing¹⁰ provided by Ronald A. Bergman, PhD.¹¹ The blue coloration represents venous flow (Figure 3).
       After careful consideration of positioning a left subclavian vein sheath through the anomaly and into the ventricle, a right ventricular lead was manipulated through a long peel-away sheath into a satisfactory position. The long peel-away sheath provided support for the manipulation of the lead into the right atrium and right ventricle. The standard pacemaker protocol measurements were taken through the lead and recorded. The tip of a positive fixation lead was then successfully attached in the right ventricular outflow tract at the septum, and measurements were again documented. The distal portion of the lead was then sutured in place within the pocket. The pacemaker was firmly attached to the pacing lead and then sutured to the pocket tissue for extra support. The pocket was easily closed without incident. After reviewing the position of the lead by fluoro to confirm proper placement, the procedure was complete. The patient’s left subclavian area was dressed with a sterile gauze and op site, and the left arm was immobilized in an arm sling. The patient then was moved from the procedure table and transported to an available room for an overnight stay.

Figure 4.

A chest x-ray showing the pacemaker positioned in the left subclavian area, attached to it is a single ventricular lead that travels through the persistent left superior vena cava, CS, right atrium and out to the right ventricular outflow tract.

       A chest x-ray taken shortly after arrival in the hospital room documented the pacemaker position in the left subclavian area with the ventricular lead tip at the ventricular outflow tract (Figures 4 and 5).

Figure 5.

A lateral chest x-ray view showing the pacemaker in the upper left subclavian area and the ventricular lead from it positioned in the PLSVC, CS and right atrium as it loops into the right ventricular outflow tract.

       The patient tolerated the procedure well and without any complications. Admission to the hospital for an overnight recovery and observation was obtained per protocol. The patient left the EP lab awake and alert, and was discharged from OHH the next day.

       Acknowledgement. Thanks to Dwayne A. Schmidt, MD for his advice and medical expertise in the completion of this article, after successful completion of this unusual procedure.