Review Question - QID 100665

This woman has suffered a thromboembolic stroke from a deep vein thrombus (DVT). A wide, fixed splitting of S2 is consistent with an ASD, which would allow direct communication from the venous system to the arterial system without traversing the lungs, thereby causing her paradoxical embolism.

The only mechanism by which a DVT can result in an embolic stroke is if there is a connection between the right heart and the left heart, such as an ASD or VSD. Signs of an ASD include a wide, fixed splitting of S2. ASDs are classified based on the location of the defect in the septum. Ostium secundum refers to a defect in the region of the fossa ovalis and make up 75% of ASDs, including patent foramen ovales. Ostium primum refers to a defect in the lower portion of the atrial septum and sinus venosus refers to defects located near the orifice of the SVC.

Illustration A is an echocardiographic image from the subcostal four chamber view showing an ASD.
Video V is an example of a systolic crescendo-decrescendo murmur as heard in aortic stenosis.

Incorrect Answers:
Answer 1: A holoystolic murmur radiating to the axilla is consistent with mitral regurgitation.
Answer 3: A crescendo-decrescendo murmur heard loudest at the right second intercostal space is consistent with aortic stenosis.
Answer 4: A holosystolic murmur that increases on inspiration is consistent with tricuspid regurgitation.
Answer 5: S2 normally splits during inspiration. Reverse splitting of S2 is indicative of aortic stenosis, hypertrophic cardiomyopathy, or left bundle branch block.