Navigating the vasculature in the presence of heterotaxy can be challenging especially when encountered in the cardiac catheterization lab for the first time. Here we present a rare case of situs ambiguus (SAMB) in a middle aged female.
A 50-year-old female smoker with a history of fistulizing Crohn’s disease was admitted for total parenteral nutrition and PICC line placement before elective bowel surgery. She was presented for a left and right heart catheterization for left ventricular dysfunction and congestive heart failure following gram negative sepsis. Notably the right heart catheter coursed up the inferior vena cavea (IVC) on the left side raising concern for perforation of the IVC into the aorta. However blood return from the IVC looked clearly venous and was confirmed by the oxygen saturation levels. A quick review of a CT angiogram demonstrated a diagnosis of SAMB. The course of the right heart catheter ultimately extended through a persistent left IVC into an azygos vein which drained into the right atrium through a persistent left sided superior vena cava emptying into the coronary sinus. Her coronary angiography demonstrated just insignificant coronary artery disease. Other findings demonstrated on CT and MR in this patient include polysplenia in mirror position, a left sided stomach, intestinal malrotation and a central liver with a double IVC. The procedure was well tolerated without any complications.
As they are usually associated with significant congenital heart disease, actual cases of SAMB in middle age are quite rare. Hence interventional cardiologists must be aware of the challenges involved when patients with lateralizing defects present.
