The question is talking about what structure you will go through to reach the left atrium for ablation due to afib
the correct option is "interatrial septum"
this card is the only card with this qID
Text from uworld
"A venous catheter traveling from the femoral vein to the heart passes through the iliac vein and inferior vena cava to reach the right atrium. Once in the right atrium, structures within the right side of the heart and the pulmonary arteries are readily accessible. However, because the pulmonary capillaries are far too small to pass through, the left side of the heart must be accessed by traversing the interatrial septum. The interatrial septum is traversed at the site of the foramen ovale, which in adults is typically covered by a thin membrane of fibrous tissue that can be easily punctured."
Source: UWorld - Step 1 15197
