Assessment of diastolic function: what the general cardiologist needs to know (2005)

iastolic dysfunction has a major impact on symptom status, functional capacity, medical treatment, and prognosis in both systolic and diastolic heart failure (HF), irrespective of the cause.w1 w2 When systolic dysfunction is clearly present, the central clinical question concerns the presence or absence of elevated filling pressure; a restrictive filling pattern is highly specific for elevated pulmonary wedge pressure in this setting. 1w3 The transmitral flow pattern is also predictive of outcome; non-reversibility of restrictive filling with treatment portends a very poor prognosis. 2Thus, diastolic evaluation is an important component of the evaluation of the patient with systolic left ventricular (LV) impairment. IS ASSESSMENT OF DIASTOLIC FUNCTION NECESSARY? cParadoxically, the role of diastolic function assessment is more difficult to define in patients with diastolic HF.Diastolic dysfunction is the predominant cardiac abnormality in this syndrome, which is associated with increased risk of hospitalisation and death. 3However, the American College of Cardiology/American Heart Association guidelines for the evaluation and management of HF w4 support a diagnosis of exclusion-that is, clinical evidence of HF with preserved systolic function.Indeed, such a definition of diastolic HF has been adopted by the majority of previous reports, w5 and is supported by the results of recent studies which indicate that the presence of diastolic dysfunction may be assumed in patients presenting with HF and normal LV ejection fraction (LVEF). 4w6 w7 Zile and colleagues demonstrated that at least one abnormal index of diastolic function was present in patients with HF and normal systolic function.These data suggest that a diagnosis of diastolic HF may accurately be made as a diagnosis of exclusion, 4 albeit in a highly selected population of relatively young, predominantly male patients who were scheduled to undergo cardiac catheterisation (contrasting with the large clinical population of elderly, hypertensive, predominantly female patients with HF and preserved systolic function).Nonetheless, a recent review has highlighted the disconnect between Doppler echo measurements and true diastolic properties of the left ventricle, and has questioned the prevailing assumption that HF with preserved systolic function is always caused by diastolic dysfunction. 5 third scenario is perhaps the most difficult.These patients present with exertional dyspnoea in the context of normal systolic function, and in this situation, symptoms may be ascribed to diastolic HF.The lack of specificity of HF symptoms has led to concern regarding the heterogeneity of patients who are labelled with diastolic HF based only upon the presence of clinical HF and normal systolic function; many such patients may in fact have non-HF causes of their clinical presentations.w8 For these reasons, recent guidelines have called for invasive determination of diastolic dysfunction to make a definite diagnosis of diastolic HF, 6 although the feasibility of this approach is limited.Doppler echocardiography is ideally suited for assessment of diastolic function, being widely available, non-invasive, and less expensive than other techniques.Echocardiographic assessment of diastolic function makes the diagnosis of diastolic HF more specific, allows serial assessment of the response of diastolic dysfunction to treatment, and facilitates inclusion of more homogeneous populations into intervention trials.Echocardiography has a broader role by allowing exclusion of overt LV systolic dysfunction (LVEF , 50%), significant valvar dysfunction (such as mitral regurgitation or aortic stenosis), and pericardial disease.However, a significant limitation is the requirement for expert interpretation of multiple parameters that vary with loading conditions and often provide conflicting information.The clinical importance of the evaluation of diastolic function warrants a simplified approach to diastology that is broadly accessible to general cardiologists.This article will therefore attempt to clarify this complex area, focusing on the practical application of Doppler echocardiography for the clinical assessment of the dyspnoeic patient, both in patients with preserved and impaired systolic function.