The Recognition and Management of Ischaemic Ventricular Dysfunction

Tweddel, Ann Cowan (1993) The Recognition and Management of Ischaemic Ventricular Dysfunction. MD thesis, University of Glasgow.

Abstract

The high incidence of obstructive coronary artery disease in the West of Scotland has resulted in a clinical problem of increasing magnitude, namely ischaemic ventricular dysfunction and its clinical correlate "heart failure". In this thesis, the history of the identification of heart failure is traced, reflecting the still present confusion as to what constitutes "heart failure" and how this should be managed. This thesis documents the use and limitations of the accepted clinical and haemodynamic measures for the identification of these patients with heart failure and the prediction of their subsequent mortality. Various non- invasive and invasive measurements were made and the overall conclusions from this work are that the appropriate differing tests require to be performed to address specific aspects, namely a) The identification of the patient with heart failure requires a combination of symptoms and the demonstration of impaired ventricular function (radionuclide angiography in this thesis). b) The assessment of the patients' clinical status, as reflected by the impact of the disease on his capacity to work is optimally assessed by measurement of gas exchange on exercise. c) The prediction of subsequent death cannot be made on the basis of clinical or haemodynamic indices, but is dependent on the extent of myocardial "loss", measured in this thesis acutely by perfusion imaging and in the chronic state by the impact on systolic function (left ventricular ejection fraction). d) Right ventricular dysfunction plays an important role for subsequent mortality, where there is associated left ventricular dysfunction. In the patient with left ventricular dysfunction as a consequence of coronary artery disease, treatment should encompass an appreciation of the absolute requirement of the myocardium for perfusion and of the factors that determine myocardial flow. These factors are often disregarded, resulting in further jeopardy of the already ischaemic myocardium. In this thesis, it is these aspects that in general have been examined with the commonly applied therapy, such as diuretics. From the work presented, it is evident that diuretics, smooth muscle relaxants, such as calcium channel blockers and inotropic agonists, exert an overall beneficial effect by maintaining myocardial perfusion whereas, for example, nitrates need to be prescribed with care as they may reduce myocardial perfusion (by reducing the blood pressure). Heart failure is easy to recognise but difficult to define. Hopefully this thesis has cast some light on the complexities of definition and management of heart failure.

• Item Type: Thesis (MD)
• Qualification Level: Doctoral
• Additional Information: Adviser: T D V Lawrie
• Keywords: Medicine
• Date of Award: 1993
• Depositing User: Enlighten Team
• Unique ID: glathesis:1993-74831
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 27 Sep 2019 15:58
• Last Modified: 27 Sep 2019 15:58
• URI: https://theses.gla.ac.uk/id/eprint/74831