On echocardiography, this is characterized by the following:įurthermore, contractile dysfunction may lead to the aortic valve appearing less mobile than it actually is. This scenario is referred to as low flow, low gradient, low ejection fraction aortic stenosis. Hence, a patient with aortic stenosis who develops contractile dysfunction will display improvement in the pressure gradient, despite the fact that the stenosis remains unchanged, or even more severe. In the setting of contractile (systolic) dysfunction, the left ventricle is unable to generate a normal increase in pressure and, accordingly, the pressure gradient across the aortic valve decreases, regardless of the stenosis. The pressure gradient is fundamental in aortic stenosis. Low flow, low gradient, low EF aortic stenosis However, it is generally not necessary if flow velocity is low (1.5 m/s or if the velocity across the aortic valve is 40 mmHg The pencil probe may be used in any view, particularly right parasternal and suprasternal views. The pencil probe is a small dual-crystal continuous wave transducer, which allows for optimal transducer positioning, angulation, and measurement of high velocities. Natural course and prognosis in aortic stenosisĪortic stenosis is generally asymptomatic until the valve area is 4ģ.5 m/s) with precision. The right coronary artery (RCA) departs from the right coronary cusp (RCC), and the left main coronary artery (LMCA) departs from the left coronary cusp (LCC). Normal (tricuspid) aortic valve with three cusps (RCC, NCC and LCC). Figure 2 shows the normal tricuspid aortic valve. Bicuspid aortic valves also increase the risk of aortic aneurysm, aortic dissection, and endocarditis. Individuals with bicuspid aortic valves may develop symptomatic aortic stenosis already at the age of 60 years. The prevalence of bicuspid aortic valves is 1% to 2% in most Western populations. Individuals with bicuspid aortic valves have substantially elevated risk of developing aortic stenosis. The aortic valve visualized in PSAX (parasternal short-axis view). Rheumatic heart disease is rare in high-income countries, presumably because streptococcal infections are treated very liberally.įigure 1 shows the aortic valve in PSAX (parasternal short-axis view). Rheumatic heart disease can occur at any age and multiple valve lesions are common (typically the aortic and mitral valve). Rheumatic heart disease is a complication of rheumatic fever, which is caused by streptococcal infections (group A Streptococcus). In low- and middle-income countries, rheumatic heart disease is the leading cause of aortic stenosis. The average age at diagnosis of aortic stenosis is 75 years in high-income countries. Risk factors for calcification overlap with risk factors for coronary heart disease (atherosclerosis). Calcification has traditionally been considered a passive degenerative process, but emerging evidence suggests it is propelled by a biologically active process. In high-income countries, the majority of cases are caused by calcification of the aortic valve. The cause of aortic stenosis displays marked geographical variations. Patients with low-flow low-gradient aortic stenosis (discussed below) have a 3-year survival rate of 50% ( Eleid et al). Aortic stenosis is a serious condition with poor long-term outcomes. This results in increased left ventricular load, while simultaneously affecting systemic perfusion. As the area is reduced, transvalvular flow resistance increases. Aortic stenosis is a progressive disease that leads to a gradual reduction in the orifice area. The aortic valve area is normally 3.0 to 4.0 cm 2.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |