A new echographic equation for estimating cardiac output correlated highly with the Fick principle (r = 0.95, SE = 340 ml) in patients with mitral stenosis.
Observational (n=10)
Does an echographic orifice formula accurately estimate cardiac output compared to the Fick principle in patients with mitral stenosis?
Effect estimate: r = 0.95
An orifice equation is demonstrated which is independent of the symmetry and kinetic state of the left ventricle. The expression allows calculation of the cardiac output in conditions of mitral stenosis when the mitral valve area is known. This equation is Q = (1/21) R A T2, where Q = cardiac output in ml/min, R = heart rate, A = mitral valve area and T = diastolic filling period in sec/min. Ten patients whose gynecologic or obstetric exam suggested a diagnosis of mitral stenosis were evaluated by conventional cardiac catheterization and M-mode echocardiography. Cardiac output computed using the new equation and the Fick principle corresponded at r = 0.95, SE = 340 ml, N = 10. These results suggest that cardiac output may be conveniently estimated for serial studies by the readily measurable echographic variables of heart rate and diastolic filling period once the mitral valve area has been measured by conventional catheterization or bi-dimensional echographic methods.
Seitz et al. (Sun,) conducted a observational in Mitral stenosis (n=10). Echographic equation for cardiac output vs. Fick principle via conventional cardiac catheterization was evaluated on Correlation of cardiac output computed using the new equation and the Fick principle (r = 0.95). A new echographic equation for estimating cardiac output correlated highly with the Fick principle (r = 0.95, SE = 340 ml) in patients with mitral stenosis.