Diastolic Echo Parameters
Meaningless Numbers or Crucial Information?
Assessment of diastolic function has emerged as another important contribution of echocardiography to the clinical care of patients. Diastolic dysfunction as diagnosed by echocardiography carries a negative prognostic value,1–3 and diastolic assessment is now a routine part of any complete echocardiographic report.4 Bhella et al,5 in this issue of Circulation: Cardiovascular Imaging, investigate the reliability of several echocardiographic diastolic parameters in predicting the pulmonary capillary wedge variation in individual subjects subjected to preload manipulation. Bhella et al controversially conclude that “Noninvasive indices do not adequately track changes in left-sided filling pressures as these pressures vary within individual subjects.” The findings are in contrast to a recent clinical paper published by Nagueh et al6 in a previous issue of the Circulation: Cardiovascular Imaging. Those authors demonstrated clinical utility of the same indices in patients with acute decompensated heart failure. How can these findings be reconciled, and what is the practicing cardiologist to do? Are the currently available diastolic parameters a bunch of meaningless numbers or crucial information in the treatment of patients?
Article see p 482
The first well-accepted parameter of diastolic function, the mitral valve filling pattern assessed by Doppler velocity measurements, reflects the gradient between the left atrium (LA) and left ventricle (LV) in diastole. The gradient is specifically sensitive to LA pressure and LV relaxation. In general, the ratio of the early wave velocity (E) to the late velocity after atrial contraction (A) was helpful in identifying the diastolic function in individual patients. However, the clear preload dependence of the E/A ratio as well as its unreliability in tachycardia, moderate diastolic dysfunction with moderately elevated LA pressures (pseudonormalization), and other issues led to the search for more reliable parameters. The …