Management of Asymptomatic Severe Aortic Stenosis
Jacob P. Dal-Bianco, MD*,
Bjoy K. Khandheria, MBBS, FACC, FASE, FESC ,
Farouk Mookadam, MD, FRCP, MSc,
Federico Gentile, MD and
Partho P. Sengupta, MBBS, MD, DM,*
* Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota
Division of Cardiovascular Diseases, Mayo Clinic, Scottsdale, Arizona
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Figure 1 Velocity-Encoded Phase Contrast Magnetic Resonance Imaging in Aortic Stenosis
Sampling planes in the left ventricular outflow tract and after the aortic valve allow measurement of quantitative flow by velocity time integration (gray area under the curve). Functional aortic valve area is then calculated by continuity equation. Adapted, with permission, from Caruthers et al. (62).
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Figure 2 Longitudinal Left Ventricular Mechanics in Asymptomatic Severe Aortic Stenosis
Continuous wave Doppler signal across the stenotic aortic valve (A) shows a peak and mean gradient of 80 and 44 mm Hg, respectively. Pulsed wave tissue Doppler from the septal corner of the mitral valve annulus (B) shows a reduced peak early diastolic longitudinal relaxation velocity (5 cm/s). Longitudinal strain obtained by speckle tracking (2D strain, GE Healthcare, Milwaukee, Wisconsin) shows attenuated peak longitudinal strain (C and D) from apical (green curve), mid (yellow curve), and basal (blue curve) of the lateral wall of the left ventricle (peak strain values <10%). Dotted white line (D) also shows a reduced global longitudinal strain averaged from the septum and lateral wall of the left ventricle (global strain = 12%). Aa = peak late diastolic annular velocity; Ea = peak early diastolic annular velocity; Sa = peak systolic velocity during ejection.
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Figure 3 Exaggerated LV Twist Mechanics in Aortic Stenosis
Peak counterclockwise rotation from apex (A) and clockwise rotation from base (B) are obtained by speckle track imaging (2D strain, GE Healthcare) of LV short-axis views of the patient shown in Figure 2. The difference of the 2 rotational values provides the peak net twist angle. This example illustrates presence of exaggerated LV rotation, particularly near the LV base with relatively high net LV twist angle value. AVC = aortic valve closure; LV = left ventricle.
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Figure 4 Stepwise Evaluation of Patients With Severe AS on the Basis of ACC/AHA and ESC Recommendations
Levels of evidence are provided in parentheses (American College of Cardiology/American Heart Association [ACC/AHA]; European Society of Cardiology [ESC]) (10,84). AS = aortic stenosis; AVA = aortic valve area; AVR = aortic valve replacement; BNP = brain natriuretic peptide; BP = blood pressure; CABG = coronary artery bypass grafting; CAD = coronary artery disease; CR = contractile reserve; EBCT = electron beam computed tomography; LV = left ventricle; LVEF = left ventricular ejection fraction.
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