Aortic stenosis is a silent killer for many patients above the age 60. However, Its chronic course → LV dysfunction & CHF can be significantly delayed, and mortality improved, if “Aortic Valve Replacement (AVR)” is performed in eligible patients at the most appropriate time.
Aortic stenosis is classified as “Severe” on the basis of 3 factors → 1. Small valve area (AVA = <1.0 cm2) 2. High peak velocity (>4 m/s) &/or 3. High mean gradient (>40 mm Hg). Patients fulfilling these criteria benefits form AVR.
Now, there are some cases where the “gradient” and “flow” might remain low, despite (+) severe aortic stenosis, due to progressive LV pressure overload and/or coexisting ischemic/post-infarction damage → This is called Classical Low Flow - Low Gradient (LF-LG) Aortic Stenosis
The LF-LG Aortic Stenosis criteria is simple to remember :
1. EF <50%
2. Mean gradient (MG) <40 mm Hg
2. Flow velocity <4.0 m/s
3. AVA (Aortic Valve Area) <1.0 cm2
1. EF <50%
2. Mean gradient (MG) <40 mm Hg
2. Flow velocity <4.0 m/s
3. AVA (Aortic Valve Area) <1.0 cm2
Now, essentially, there are two types of such LF-LG Aortic stenosis →
1. True-severe aortic stenosis &
2. Pseudo-severe aortic stenosis
The former has mortality benefit from AVR (Aortic Valve Replacement) & the later “does not.”
So how to differentiate between the two ? 🤨
1. True-severe aortic stenosis &
2. Pseudo-severe aortic stenosis
The former has mortality benefit from AVR (Aortic Valve Replacement) & the later “does not.”
So how to differentiate between the two ? 🤨
Differentiation between True severe and Pseudo-severe aortic stenosis, as well as an estimation of LV contractile reserve are feasible by something called “Dobutamine-stress ECHO test.”
Low dose Dobutamine about 5 to 20 μg/kg/min at 3–5-minute intervals under monitoring is given
Low dose Dobutamine about 5 to 20 μg/kg/min at 3–5-minute intervals under monitoring is given
Result 1 :
Patients with >20% increase in LV stroke volume + Trans-valvular gradient reaching >40 mm Hg “without” an increase in AVA by > 1.0 cm2 → True-severe aortic stenosis with preserved flow reserve.
Patients with >20% increase in LV stroke volume + Trans-valvular gradient reaching >40 mm Hg “without” an increase in AVA by > 1.0 cm2 → True-severe aortic stenosis with preserved flow reserve.
Result 2 :
Patients with >20% increase in LV stroke volume + accompanied by significant AVA increase by >1.0 cm2 “without” simultaneous rise of the gradient (i.e., remains <40 mm Hg) → Pseudo-severe Aortic Stenosis.
Patients with >20% increase in LV stroke volume + accompanied by significant AVA increase by >1.0 cm2 “without” simultaneous rise of the gradient (i.e., remains <40 mm Hg) → Pseudo-severe Aortic Stenosis.
The Bottom Line conclusion :
True-severe aortic stenosis → Mortality benifit from AVR
Psuedo-severe aortic stenosis → No Mortality benifit from AVR ; Medical therapy would suffice
#CardioEd #MedEd #CardioTwitter #MedStudentTwitter #AcademicTwitter
True-severe aortic stenosis → Mortality benifit from AVR
Psuedo-severe aortic stenosis → No Mortality benifit from AVR ; Medical therapy would suffice
#CardioEd #MedEd #CardioTwitter #MedStudentTwitter #AcademicTwitter
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