Chapter 47: Aortic Valve Disease
A 65-year-old man was referred for cardiac consultation following a 2-year history of dyspnea on minimal exertion. He had a coronary angiography in the past that revealed normal coronaries. His physical examination revealed a 3/6 systolic ejection systolic murmur across the precordium. An echo was obtained showing left ventricular dysfunction with an EF of 38%, a calcified aortic valve with a mean gradient of 29 mm Hg, and AVA (aortic valve area) of 0.9 cm2. Which of the following is the best next step in the management of this patient?
A. SAVR after coronary angiography
B. Left and right cardiac catheterization
C. Exercise treadmill testing
E. Dobutamine stress echocardiography (DSE)
The answer is E. (Hurst’s The Heart, 14th Edition, Chap. 47) There is a discrepancy between gradient and valve area calculation, and this needs to be sorted out before making any decision with regard to the interventions (options A and D are thus not correct). This patient may have low-flow/low-gradient severe AS with reduced EF. AS severity may be difficult to assess under resting conditions in low LVEF patients,1-5 and DSE (option E) can help clarify the issue by allowing reassessment of the AVA at a higher flow. With normalized flow, a patient with true severe AS increases the mean transaortic gradient in tandem with valve flow so that AVA remains nearly constant. A patient with pseudo-severe AS, a condition where low flow causes an overestimation of AS severity, increases valve flow with little increase in gradient, resulting in increased AVA. Options B and C would not be useful in resolving the discrepancy between gradient and valve area calculation in this case.
A 67-year-old man with a prior medical history of hypertension and atrial fibrillation was referred for cardiac consultation following a 2-year history of chest discomfort on minimal exertion. His physical examination revealed a late peaking 3/6 ejection systolic murmur with a soft and single S2. An echo was obtained showing left ventricular hypertrophy with an EF of 62%, moderate right ventricular dysfunction, moderate mitral regurgitation, a calcified aortic valve with a mean gradient of 29 mm Hg, and AVA of 0.7 cm2. Which of the following parameters may not be a contributor to paradoxical low-flow, low-gradient severe aortic stenosis?
A. Hypertensive heart disease
C. Right ventricular dysfunction
D. Occult aortic regurgitation