Value of Doppler echocardiography for quantifying valvular stenosis or regurgitation.

Du uring the past 2 decades there has been considerable enthusiasm for the development and use of noninvasive techniques for the initial and serial evaluation of patients with valvular heart disease. The results obtained with noninvasive methods often have altered the decision-making process, particularly when the physician is unsure of the severity of valvular stenosis and regurgitation after a routine clinical evaluation or when the results of noninvasive testing are applied to subgroups of patients in whom the history, physical examination, electrocardiogram, and other routine tests provide less precise positive or negative data. An important example is the elderly patient with vague symptoms of heart disease, with systolic hypertension, and with physical findings that may represent severe valvular aortic stenosis. Considering the increasing number of elderly patients, most of whom have a basal midsystolic murmur and considering the poor short-term prognosis without surgery of patients with severe symptomatic aortic stenosis and considering the excellent results of aortic valve replacement in all age groups, an accurate noninvasive method for quantifying the severity of aortic valve stenosis is highly desirable. An accurate, reproducible, noninvasive method that quantifies the severity of valvular stenosis or regurgitation may indicate the absence of valvular disease and the need for no further testing, mild-to-moderate valvular heart disease requiring serial follow-up by noninvasive studies, or severe disease necessitating cardiac surgery. Cardiac catheteriza-tion may not be required, particularly in young patients without symptoms or risk factors for coin-cident coronary artery disease. Until recently, the available noninvasive techniques , with few exceptions,' have provided only indirect information about the severity of valvular stenosis or regurgitation and have focused on such consequences of the valvular disease as ventricu-lar hypertrophy or dilatation, atrial dilatation, pulmonary venous hypertension, impaired ventric-ular performance, or a reduced stroke volume. In the past, the accurate quantification of the severity of valvular stenosis or regurgitation has generally required cardiac catheterization often with contrast cineangiography.2-4 With the advent of Doppler echocardiography in the middle 1970s and its refined application to many patients with valvular heart disease in the subsequent decade, a noninvasive method has become available for determining accurately the extent of valvular stenosis or regurgitation, often providing quantitative data for making patient-related decisions. The transvalvular pressure gradient can be calculated directly from blood velocity data by a modification of Bernoulli's equation to calculate the convective energy loss as blood passes through the stenotic orifice.5 Stroke volume, valve area, …