The Correct Answer is C!
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A 75 year-old woman with a past medical history of only hyperlipidemia and osteopenia is seen in the office for routine annual physical. She is active and walks her dog 1 mile daily around the neighborhood. Lately, she has noticed that she has had to stop to catch her breath near the end of her walk. She denies chest pain, presyncope, syncope, or lower extremity edema. Her medications are atorvastatin and vitamin D/calcium supplements. Her physical exam shows a heart rate of 70 bpm, blood pressure of 162/82 mmHg. Her lungs are clear to auscultation. On cardiac exam, S1 and S2 are heard with presence of an S4. A grade 3/6 late-peaking systolic murmur is best heard at the right second intercostal space, with radiation into the right carotid artery. The rest of her exam is unremarkable.
Which of the following diagnostic tests is most appropriate at this time?
- Cardiac catheterization
- Treadmill stress echocardiogram
- Transthoracic echocardiogram
- No further testing
Based this patient’s history and exam, aortic stenosis (AS) should be suspected. In the normal tricuspid valve, the most common cause of AS is progressive calcific valve disease and is much like atherosclerosis with similar risk factors such as male sex, older age, smoking history, hypertension, hyperlipidemia, and diabetes. Other causes of AS are early calcific disease in the congenital bicuspid valve and rheumatic disease. The initial test in this case should be transthoracic echocardiogram (TTE). The ACC/AHA guidelines make a class I recommendation for TTE in patients with signs or symptoms of known or suspected valvular disease to confirm diagnosis and also to assess etiology, severity, hemodynamic consequences, prognosis, and need/timing of intervention. Significant valvular disease should be suspected in grade 3/6 or higher murmur or presence of symptoms. In the diagnosis of AS, TTE can assess hemodynamic severity using parameters including maximum transvalvular velocity, mean pressure gradient, and aortic valve area. Exercise stress testing is not the preferred screening test in this case but can be indicated in asymptomatic patients with known valvular heart disease to confirm absence of symptoms, evaluate hemodynamic response to exercise, and gain prognostic information. In AS however, severe stenosis, history of angina, congestive heart failure, or exertional syncope are absolute contraindications to exercise stress testing. Cardiac catheterization is usually not the primary evaluation tool in suspected valvular disease. However, it can be indicated as part of the workup to assess hemodynamics in symptomatic patients when noninvasive tests are inconclusive, or if there is inconsistency between findings on noninvasive testing and physical examination regarding severity of the valve lesion. Also in patients with atherosclerotic risk factors and valvular disease requiring cardiac surgery, coronary angiography should be done to assess whether simultaneous coronary artery bypass grafting is needed.
1. Source: "Comparative Analysis of Pre/Post Assessments of Live/Didactic Course Attendees when compared to Mico-Learning/Online Course Users., "Knowledge to Practice, 2017.