A patient needs a pacemaker,and the cardiologist plans to run the pacemaker electrode into the right atrium via the left subclavian vein.As the cardiologist monitors the placement of the catheter using angiography,he discovers that the catheter will not enter the superior vena cava.Rather,it enters the coronary sinus and then the right atrium.How is this possible?

Question

Quizplus · Accepted Answer

The left superior vena cava is a congenital anomaly where the left brachiocephalic vein connects to the coronary sinus instead of the right atrium. This anomaly is present in around 0.5% to 1% of the population and can be discovered during procedures that involve accessing the venous system, such as placing a pacemaker electrode via the left subclavian vein.

A Patient Needs a Pacemaker,and the Cardiologist Plans to Run