The role of contemporary echocardiography in the management of heart failure
Heart failure (HF) is an increasing and leading cause of cardiovascular morbidity, hospitalisation and death. Echocardiography is often used in HF patients because it provides important aetiological, diagnostic and prognostic information to assist physician management at moderate cost. This thesis has explored contemporary echocardiographic techniques for assessment of both diastolic and systolic function to ascertain their effectiveness and optimal utility. Assessment of systolic function in HF patients is optimised by the use of harmonic imaging and not enhanced with the use of transpulmonary contrast agents, whilst diastolic filling is optimised by the use of preload manipulation. When optimised in this way, echocardiography can be used to stratify HF patients in terms of risk of death and/or hospitalisation after discharge from hospital. This was confirmed in a meta-analysis of more than 6000 patients (1000 deaths) with HF or after acute myocardial infarction (AMI), where the presence of restrictive filling pattern (the most severe form of diastolic dysfunction) was associated with a four-fold increase in mortality in both patient groups. In addition, restrictive filling pattern also predicted development of HF post AMI and hospitalisation in patients with HF. This meta-analysis also evaluated the intermediate stages of diastolic dysfunction and found a stepped relationship between each grade and prognosis. The last part of this thesis explored the role of contemporary echocardiography for management of symptomatic patients in the community and found that the diagnosis of HF in the community may be optimised by using brain natriuretic peptide (BNP) as a first test to "rule-out" heart failure and then echocardiography, which was superior to BNP in patients with intermediate BNP levels to diagnose HF. Furthermore, the systolic echocardiographic parameters were important for diagnosis, whilst the diastolic parameters predicted future hospitalisation. In summary, contemporary echocardiography in HF patients should include comprehensive assessment of systolic function (using tissue harmonics imaging) and diastolic filling (utilising preload manipulation). This approach will optimise both diagnosis and prognosis and in turn may aid physician management.
Networked Digital Library of Theses and Dissertations