Diagnostic-studies-aortic-stenosis

• ECG: may see LVH, LAE, LBBB, AF (in late disease)
• CXR: cardiomegaly, AoV calcification, poststenotic dilation of ascending Ao, pulmonary congestion
• Echo: valve morph., jet velocity → estimate pressure gradient (∇) & calculate AVA, dimensionless index (DI); LVEF
• Cardiac cath: usually to r/o CAD (in ~½ of calcific AS); for hemodyn. if disparity between exam & echo: ✓ pressure gradient (∇) across AoV, calc AVA (underestim. if mod/sev AR)
• Dobutamine challenge (echo or cath): if low EF and mean ∇ <40, use to differentiate: Afterload mismatch: 20% ↑ SV & ∇, no ∆ AVA (implies contractile reserve, ↑ EF post-AVR) Pseudostenosis: 20% ↑ SV, no ∆ in ∇, ↑ AVA (implies low AVA artifact of LV dysfxn) Limited contractile reserve: no ∆ SV, ∇ or AVA (implies EF prob. will not improve w/ AVR)

a AVA indexed to BSA <0.6 cm2/m2 also severe (use for smaller Pts); b DSE → max jet vel ≥4 & AVA ≤1.0; cSmall LV w/ ↓ stroke vol (LVSVi <35 mL/m2), severe LVH with marked diastolic dysfunction, consider cardiac amyloid