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A sequential evaluation of left ventricular function in asymptomatic and symptomatic patients with chronic severe aortic regurgitation
The optimal timing of valve replacement surgery in chronic severe aortic regurgitation (AR) has remained a major clinical problem in the management of these patients. Although the onset of symptoms is the generally accepted indication for aortic valve replacement (AVR), the unpredictable development...
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| Format: | Thesis |
| Language: | Eng |
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Division of Cardiology
2017
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| _version_ | 1867613792052969472 |
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| access_status_str | Open Access |
| author | Sarembock, Ian J |
| author2 | Beck, Walter |
| author_browse | Beck, Walter Sarembock, Ian J |
| author_facet | Beck, Walter Sarembock, Ian J |
| author_sort | Sarembock, Ian J |
| collection | Thesis |
| description | The optimal timing of valve replacement surgery in chronic severe aortic regurgitation (AR) has remained a major clinical problem in the management of these patients. Although the onset of symptoms is the generally accepted indication for aortic valve replacement (AVR), the unpredictable development of pre-symptomatic left ventricular (LV) dysfunction as a result of prolonged volume overload has resulted in numerous reports attempting to formulate a risk profile for these patients. Although aortic root and LV cineangiography have been the "gold standard" for defining the severity of AR and its effect on LV performance, serial follow-up by these means is impractical. More recently numerous non-invasive measures of LV size (echocardiogram) and function both at rest and on exercise (echocardiogram and equilibrium radionuclide angiocardiography., ERNA) have been serially utilised~ In these endeavours, the thinking has been clouded by a tendency to equate these two measures and failing to appreciate that apparent preoperative LV dysfunction (particularly on exercise) may be rapidly reversible by AVR and the consequent changes in LV loading conditions. This study was a prospective, sequential evaluation of left ventricular function using both non-invasive and invasive techniques in symptomatic and asymptomatic patients with isolated chronic, severe (4+) AR at cardiac catheterisation. The aims of the study were to (I) Identify differences in the clinical, echocardiographic, resting and exercise haemodynamic and I radionuclide measures of left ventricular function in symptomatic and asymptomatic patients with chronic severe A.R. with particular reference to the incidence of presymptomatic development of left ventricular dysfunction. (II) Critically evaluate the role of exercise stress (both isotonic and isometric) in the assessment of patients with chronic severe A.R. (III) Evaluate the influence of time (sequential studies) on the haemodynamic burden in asymptomatic patients. (IV) Study the impact of successful aortic valve replacement on the reversibility of abnormal pre-operative LV function in an attempt to predict which patients would benefit from this therapeutic intervention and whether operation for symptoms alone is the correct clinical practice. |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/25737 |
| institution | University of Cape Town (South Africa) |
| language | Eng |
| last_indexed | 2026-06-10T12:41:46.447Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository |
| publishDate | 2017 |
| publishDateRange | 2017 |
| publishDateSort | 2017 |
| publisher | Division of Cardiology |
| publisherStr | Division of Cardiology |
| record_format | dspace |
| source_str | UCTD — University of Cape Town Open Access Repository |
| spelling | oai:open.uct.ac.za:11427/25737 A sequential evaluation of left ventricular function in asymptomatic and symptomatic patients with chronic severe aortic regurgitation Sarembock, Ian J Beck, Walter Commerford, Patrick Aortic Valve Insufficiency~Aortic Valve - surgery~Heart ventricle The optimal timing of valve replacement surgery in chronic severe aortic regurgitation (AR) has remained a major clinical problem in the management of these patients. Although the onset of symptoms is the generally accepted indication for aortic valve replacement (AVR), the unpredictable development of pre-symptomatic left ventricular (LV) dysfunction as a result of prolonged volume overload has resulted in numerous reports attempting to formulate a risk profile for these patients. Although aortic root and LV cineangiography have been the "gold standard" for defining the severity of AR and its effect on LV performance, serial follow-up by these means is impractical. More recently numerous non-invasive measures of LV size (echocardiogram) and function both at rest and on exercise (echocardiogram and equilibrium radionuclide angiocardiography., ERNA) have been serially utilised~ In these endeavours, the thinking has been clouded by a tendency to equate these two measures and failing to appreciate that apparent preoperative LV dysfunction (particularly on exercise) may be rapidly reversible by AVR and the consequent changes in LV loading conditions. This study was a prospective, sequential evaluation of left ventricular function using both non-invasive and invasive techniques in symptomatic and asymptomatic patients with isolated chronic, severe (4+) AR at cardiac catheterisation. The aims of the study were to (I) Identify differences in the clinical, echocardiographic, resting and exercise haemodynamic and I radionuclide measures of left ventricular function in symptomatic and asymptomatic patients with chronic severe A.R. with particular reference to the incidence of presymptomatic development of left ventricular dysfunction. (II) Critically evaluate the role of exercise stress (both isotonic and isometric) in the assessment of patients with chronic severe A.R. (III) Evaluate the influence of time (sequential studies) on the haemodynamic burden in asymptomatic patients. (IV) Study the impact of successful aortic valve replacement on the reversibility of abnormal pre-operative LV function in an attempt to predict which patients would benefit from this therapeutic intervention and whether operation for symptoms alone is the correct clinical practice. 2017-10-23T08:38:09Z 2017-10-23T08:38:09Z 1987 2017-07-24T10:03:02Z Doctoral Thesis Doctoral MD http://hdl.handle.net/11427/25737 Eng application/pdf Division of Cardiology Faculty of Health Sciences University of Cape Town |
| spellingShingle | Aortic Valve Insufficiency~Aortic Valve - surgery~Heart ventricle Sarembock, Ian J A sequential evaluation of left ventricular function in asymptomatic and symptomatic patients with chronic severe aortic regurgitation |
| thesis_degree_str | Doctoral |
| title | A sequential evaluation of left ventricular function in asymptomatic and symptomatic patients with chronic severe aortic regurgitation |
| title_full | A sequential evaluation of left ventricular function in asymptomatic and symptomatic patients with chronic severe aortic regurgitation |
| title_fullStr | A sequential evaluation of left ventricular function in asymptomatic and symptomatic patients with chronic severe aortic regurgitation |
| title_full_unstemmed | A sequential evaluation of left ventricular function in asymptomatic and symptomatic patients with chronic severe aortic regurgitation |
| title_short | A sequential evaluation of left ventricular function in asymptomatic and symptomatic patients with chronic severe aortic regurgitation |
| title_sort | sequential evaluation of left ventricular function in asymptomatic and symptomatic patients with chronic severe aortic regurgitation |
| topic | Aortic Valve Insufficiency~Aortic Valve - surgery~Heart ventricle |
| url | http://hdl.handle.net/11427/25737 |
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