WBR0549
| Author | [[PageAuthor::Rim Halaby, M.D. [1]]] |
|---|---|
| Exam Type | ExamType::USMLE Step 1 |
| Main Category | MainCategory::Physiology |
| Sub Category | SubCategory::Cardiology |
| Prompt | [[Prompt::A 21 year old woman, previously healthy, presented to the out-patient clinic for dyspnea on exertion. Her labs showed significant iron deficiency anemia, and appropriate therapy was initiated. During her work-up she was also found to have a bicuspid aortic valve on echocardiogram. Which of the following best represents her predicted pressure-volume loop at age 65 (red curve) compared to a normal individual (black curve)?]] |
| Answer A | AnswerA:: |
| Answer A Explanation | AnswerAExp:: |
| Answer B | AnswerB:: |
| Answer B Explanation | AnswerBExp:: |
| Answer C | AnswerC:: |
| Answer C Explanation | AnswerCExp:: |
| Answer D | AnswerD:: |
| Answer D Explanation | AnswerDExp:: |
| Answer E | AnswerE:: |
| Answer E Explanation | AnswerEExp:: |
| Right Answer | RightAnswer:: |
| Explanation | [[Explanation::
Bicuspid aortic valve (BAV) is a common congenital cardiac defect with an incidence ranging between 0.9% and 2.0% of the general population. BAV occurs due to abnormal valvulogenesis where 2 adjacent cusps fuse to form a single cusp. In the majority of cases, it is asymptomatic at an early age and either discovered incidentally, or after an episode of endocarditis. In older patients, aortic stenosis is the most common syndrome due progressive calcification of the valve. Approximately 50% of patients with severe aortic stenosis before age 70 have bicuspid aortic valves. The pressure-volume loop of aortic stenosis shows reduced ventricular stroke volume due to increased afterload with marked increase in ventricular systolic pressure. Educational objective: BAV usually causes early aortic stenosis with pressure-volume loop showing reduced ventricular stroke volume and increased afterload. References:
Sagawa K. The end-systolic pressure-volume relation of the ventricle: definition, modifications and clinical use. Circulation. 1981;63(6):1223-7.
Abdulkareem N, Smelt J, Jahangiri M. Bicuspid aortic valve aortopathy: genetics, pathophysiology and medical therapy. Interact Cardiovasc Thorac Surg. 2013;17(3):554-9. |
| Approved | Approved::No |
| Keyword | |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |