Echocardiographic Assessment of Diastolic Function and Diagnosis of Diastolic Heart Failure

Asymptomatic diastolic dysfunction in the general population is common, even in patients without congestive heart failure, 1,2 and the prevalence of moderate to severe diastolic dysfunction in asymptomatic patients increases in patients >65 years old with associated hypertension and coronary artery disease. The presence of diastolic dysfunction alone predicts worse outcome, with worse prognosis as the degree of diastolic dysfunction increases. Thus, it is important to identify and treat underlying problems (most frequently, hypertension) in patients with diastolic dysfunction. In population-based studies, diastolic heart failure (DHF) accounts for up to half of patients with the diagnosis of congestive heart failure [2– 6]. Although DHF can be diagnosed clinically by documenting the presence of signs and symptoms of heart failure and preserved systolic function (EF ≥50%), objective evidence of diastolic dysfunction and increased fi lling pressure should also be demonstrated. Evaluation of diastolic function consists of assessing myocardial relaxation, fi lling pressures, and left ventricular (LV) compliance. Although diastolic dysfunction can be diagnosed invasively by cardiac catheterization, this is not always feasible or practical. Both two-dimensional and Doppler echocardiography can be used to noninvasively assess diastolic function. Although systolic function and major cardiac structures are usually normal in patients with DHF, twodimensional echocardiography is useful in identifying changes, although subtle, associated with cardiac diseases that result primarily in diastolic dysfunction. These changes include reduced motion of the mitral annulus, increased left atrial size, and frequently increased LV wall thickness. Left ventricular diastolic function is more objectively characterized by the mitral infl ow pattern, pulmonary and hepatic vein Doppler velocities, tissue Doppler imaging of the mitral annulus, and color fl ow imaging of mitral infl ow.