Low flow low gradient aortic stenosis resident survival guide
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Rim Halaby, M.D. [2]
Definition
When severe systolic and/or diastolic myocardial dysfunction coexist with aortic stenosis, there is a decrease in the flow through the valve leading to a prominent decrease in the transvalvular gradient, a condition referred to as low flow low gradient aortic stenosis (LF-LG AS). LF-LG AS with low LVEF is defined as:
- An aortic valve areas < 1.0 cm2, and
- A left ventricular ejection fraction < 40%[1] ( 30% in other references),[2] and
- A mean pressure difference or gradient across the aortic valve of < 30 mm Hg
- When low flow low gradient aortic stenosis is present, the challenge is to determine whether the LF-LG AS with low LVEF is a true severe aortic stenosis or a pseudo-severe aortic stenosis. It is very important to differentiate these two entities as they have different outcomes following aortic valve replacement.[1]
Management
Shown below is an algorithm of the management of low flow, low gradient aortic stenosis.[1]
| Ultrasound evaluation of aortic stenosis Effective orifice area (EOA)≤ 1 cm2 Pressure gradient (ΔP)<40 mmHg | |||||||||||||||||||||||
| Low grade low flow aortic stenosis | |||||||||||||||||||||||
| Normal left ventricular ejection fraction | Left ventricular ejection fraction≤ 40% | ||||||||||||||||||||||
| No specific recommendations: - Surgical AVR, or - Transcather AVR, or - Medical treatment | |||||||||||||||||||||||
| Dobutamine stress test | |||||||||||||||||||||||
| Increase in stroke volume by ≥ 20% | Increase in stroke volume by <20% | ||||||||||||||||||||||
| Presence of left ventricular flow reserve | Absence of left ventricular flow reserve | ||||||||||||||||||||||
| ΔP≥40 EOA<1-1.2 | ΔP<40 EOA≥1-1.2 | EOA<1-1.2 | |||||||||||||||||||||
| True severe aortic stenosis | Pseudo-severe aortic stenosis | True severe aortic stenosis | |||||||||||||||||||||
| Surgical AVR with/without CABG | Medical treatment Close follow up | Transcather AVR | |||||||||||||||||||||
References
- ↑ 1.0 1.1 1.2 Pibarot P, Dumesnil JG (2012). "Low-flow, low-gradient aortic stenosis with normal and depressed left ventricular ejection fraction". J Am Coll Cardiol. 60 (19): 1845–53. doi:10.1016/j.jacc.2012.06.051. PMID 23062546.
- ↑ Connolly HM, Oh JK, Schaff HV, Roger VL, Osborn SL, Hodge DO; et al. (2000). "Severe aortic stenosis with low transvalvular gradient and severe left ventricular dysfunction:result of aortic valve replacement in 52 patients". Circulation. 101 (16): 1940–6. PMID 10779460.