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The Case Files

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The Case Files is an anecdotal collection of emergency medicine cases to enable physicians and researchers to find clinically important information on unusual conditions.

Case reports should focus on:

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Tuesday, May 14, 2019

An Incidental Finding While Placing a Central Line


A 68-year-old male nursing home resident with a history of hypertension, cerebrovascular accident, COPD, and chronic respiratory failure with a tracheostomy presented to the ED with a 101°F fever of four days that didn't respond to Tylenol. The patient was alert and oriented x0. His Glasgow Coma Scale score was 5.

The patient was tachypneic at 30 bpm, and three systolic blood pressures fell below 100 mm Hg. An initial chest x-ray revealed bilateral pulmonary infiltrates and a left-sided pleural effusion, raising suspicion for pneumonia as the most probable cause of sepsis. His persistent hypotension did not respond to IV fluids, so a left internal jugular central line was placed in anticipation of the need for vasopressors. Ultrasonography was used to aid in line placement, and a non-pulsatile, compressible internal jugular vein was seen. An introducer needle was inserted, and dark venous blood was drawn on the first attempt. Central venous pressure tracings were consistent with venous waveforms.

A chest x-ray was ordered to confirm line placement. The line had extended to the left side of the heart, raising concern for arterial cannulation. A contrast CT scan was ordered to better characterize the intrathoracic anatomy and the extent of the pneumonia. It revealed a left-sided pleural effusion and a left-sided superior vena cava draining into the coronary sinus but not a right-sided superior vena cava. (Image 1.) The line was left in place due to correct venous cannulation.

case files-mizuno 1.jpg

Image 1. CT scan of the chest with contrast visualizing the left-sided superior vena cava.

Ultrasound is used to guide the central line insertion. Confirmation of line placement is assessed by chest x-ray. The catheter tip should be visualized in the right heart at the junction between the superior vena cava and the right atrium. The x-ray of our patient showed the catheter tip projecting in the left thorax. (Image 2.) This initially raised concern for arterial catheter placement, but the pressure tracings obtained by manometry confirmed venous cannulation. A contrast CT scan supported the venous location of the catheter in an anomalous left-sided superior vena cava (LSVC) draining into the coronary sinus.

case files-mizuno 2.jpg

Image 2. Drainage of the left-sided superior vena cava into the coronary sinus on CT with contrast.

Obliteration of the left posterior cardinal vein normally occurs in late embryonic life because of compression between the left atrium and the hilum of the left lung, which leads to the absence of an LSVC. Any disruption of this compression pattern will result in the persistence of an LSVC. This is one of the most common abnormalities of the venous circulation. Most case reports with a persistent LSVC have reported a coexisting RSVC. Our patient did not have a RSVC, however.

A dilation in the coronary sinus is often the first indication of an LSVC. When an LSVC is present, the drainage commonly falls into the coronary sinus. This leads to an enlargement of the coronary sinus, which can be seen on angiography. This drainage doesn't present with a shunt between the arterial and venous circulation. Any other patterns of drainage or congenital heart defects can lead to a right to left shunt.

Up to 0.5 percent of the population has an LSVC. Typically, this is an incidental finding with little functional importance. An ultrasound-guided central venous line placement may raise initial suspicion for the anomaly if unexpected resistance is felt. Resistance may indicate arterial placement of the line. Chest x-ray will show the line in the left thorax in a patient with an LSVC. A venous waveform on manometry and confirmatory contrast CT will show venous line placement in an anomalous LSVC.

The diagnoses of an LSVC is most commonly made incidentally in the occasion of a central line placement. LSVC should be considered in a patient with unusual central line placement. The post-procedural chest x-ray will show the catheter tip in the left heart raising suspicion for arterial involvement. Catheter tip manometry and careful review of waveform tracings should be used in these cases to confirm venous line placement. A contrast CT scan will definitively diagnose the presence of an LSVC.


    • Webb WR, Gamsu G, et al. Computed tomographic demonstration of mediastinal venous anomalies. AJR Am J Roentgenol. 1982;139[1]:157.
    • Goyal SK, Punnam SR, et al. Persistent left superior vena cava: A case report and review of literature. Cardiovasc Ultrasound. 2008;6:50;
    • Cambell M, Deuchar DC. The left-sided superior vena cava. Br Heart J. 1954;16[4]:423;
    • Voci P, Luzi G, Agati L. Diagnosis of persistent left superior vena cava by multiplane transesophageal echocardiography. Cardiologica. 1995;40[4]:273.
Mr. Cruz is a third-year medical student from the University of Medicine and Health Sciences in St. Kitts. Ms. Bornia is a fourth-year medical student at the Windsor University School of Medicine in St. Kitts. Dr. Mizuno is a board-certified internist, an associate professor at the Northwestern Feinberg School of Medicine, and an attending at Weiss Memorial Hospital.