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Sep 13, 2023 · Aortic stenosis grading takes into account your mean transvalvular gradient (mean gradient) — that is, the average pressure across the aortic valve between the left ventricle and aorta. Like your blood pressure, the mean gradient is measured in millimeters of mercury (mm Hg). Normally, a healthy aortic valve has minimal if any mean gradient.
- Introduction
- Heterogeneity of Low-Gradient Aortic Stenosis
- The Classic ‘Low-Flow Low-Gradient’ Aortic Stenosis
- The Paradoxical Low-Flow Low-Gradient Aortic Stenosis
- The Normal-Flow Low-Gradient Aortic Stenosis
- Practical Guide to The Diagnostic Definition of Low-Gradient Aortic Stenosis
- Low-Gradient Aortic Stenosis Prognosis
- Low-Gradient Aortic Stenosis Therapy
- Choice of The Type of Intervention
- Conclusions
Aortic stenosis (AS) is the most common valve disease in developed countries and the most frequently treated. Treatment decision is guided by (i) severity of stenosis, (ii) symptoms, and (iii) reduced left ventricular ejection fraction (LVEF). According to the guidelines,1,2 AS is defined as severe in the presence of a mean gradient ≥40 mmHg, aorti...
An essential element in understanding low-gradient AS is the relationship between the transaortic gradient and flow. In fact, according to the simplified Bernoulli equation, the transvalvular gradient is equal to 4 × V2, where V is the flow velocity. Therefore, even a small reduction in transaortic flow results in a significant reduction in the gra...
In patients with AS and left ventricular dysfunction, the clinical entity classically referred to as ‘low-flow, low-gradient AS’ is configured. Typically, these patients have AVA ≤1 cm2, mean gradient <40 mmHg, and EF <50%. This clinical phenotype is present in 5–10% of patients with AS, is more common in men and is often associated with coronary a...
This clinical entity occurs in patients whose LVEF is normal. The diagnostic criteria are: AVA ≤1 cm2 (or indexed AVA ≤0.6 cm2/m2), mean gradient <40 mmHg, LVEF≥ 50% and low transaortic flow, i.e. SVI ≤35 mL/m2. It is present in 5–25% of patients with AS and is more frequent in women and in the elderly and is often associated with a history of hype...
This clinical phenotype of AS is characterized by LVEF >50%, normal transaortic flow, i.e. >35 mL/m2, AVA ≤1 cm2 (or indexed AVA ≤ 0.6 cm2/m2) and a gradient <40 mmHg. This pattern is present in up to 25% of patients with AS, and up to 50% of these AS are really severe.4 In addition to the presence of reduced vascular compliance and hypertension, t...
In clinical practice, the diagnostic definition of a low-gradient AS can be quite complex because there are many anatomical and flow parameters to consider. First of all, facing a patient with a moderate transaortic gradient (i.e. between 20 and 39 mmHg) and a Doppler area ≤1 cm2 (or indexed ≤0.6 cm2/m2) it is essential to verify that the valve has...
Patients with classic low-flow low-gradient AS have a particularly poor prognosis when managed with medical therapy.7,8 However, in these patients also the operative risk is very high, especially if treated surgically, with a 30-day mortality between 6% and 33%.9 Correct stratification of operative risk is therefore essential. DSE has been shown9 t...
Once it has been confirmed that the patient with low-gradient AS actually has severe AS, international guidelines agree on the indication for AVR, based on numerous (though not randomized) studies that have documented its efficacy.1,2 In patients with classic low-low flow low-gradient AS, both the American and European guidelines recognize a class ...
Surgical or transcatheter AVR [transcatheter aortic valve implantation (TAVI)] represent the therapeutic options available for the treatment of severe AS. In particular, in the subset of patients with low-gradient AS, the choice between the two options must be individualized, made by the Heart Team and based on multiple factors that include surgica...
The ‘low-gradient AS’ includes very heterogeneous clinical entities, with different pathophysiological mechanisms. Once the degree of severity has been confirmed, which implies a poor prognosis, surgical or percutaneous treatment is indicated, depending on the risk and comorbidities of the individual patient. Conflict of interest:none declared.
- Vittoria Rizzello
- 2021
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Aug 9, 2022 · The calculated valve area does not depend on the HR in the same way that echocardiographic calculations require because HR and the mean gradient are intrinsic to the Gorlin formulas. With irregular rhythms, such as atrial fibrillation, averaging the data over 10 beats rather than using a single beat is more accurate.
Mean corpuscular volume (MCV) is a value calculated during a routine blood test called a complete blood count (CBC). MCV measures the average size of your red blood cells. Your red blood cells carry oxygen throughout your body. This oxygen, in turn, powers your cells. The characteristics of your red blood cells — including size — provide ...
Sep 6, 2017 · If the MCV results in a blood test show that the red blood cell volume is too low, this could be a sign of iron deficiency anemia, chronic blood loss, or a blood disorder. If the mean corpuscular blood cell volume is too high, then it could be a symptom of a vitamin B deficiency, excess alcohol consumption, problems with your liver function, or ...
Nov 14, 2023 · A mean corpuscular volume (MCV) blood test measures the size of your red blood cells. It is included in a routine blood panel known as a complete blood count (CBC). Red blood cells carry oxygen through your body. A low MCV means your red blood cells are smaller than average, which could indicate iron deficiency anemia.
Jul 4, 2022 · Mean corpuscular volume (MCV) is a laboratory value that measures the average size and volume of a red blood cell. It has utility in helping determine the etiology of anemia — calculation of the value is by multiplying the percent hematocrit by ten divided by the erythrocyte count. Along with the hemoglobin and hematocrit, MCV can determine the classification of anemia as either microcytic ...
