No limiar anaeróbico ventilatório exercício pode causar isquemia miocárdica em programa de reabilitação cardiovascular
Background: Myocardial ischemia may occur during an exercise session in cardiac rehabilitation programs. However, it has not been established whether it is elicited when exercise prescription is based on heart rate corresponding to the anaerobic threshold as measured by cardiopulmonary exercise test...
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| Format: | doctoral thesis |
| Status: | Published version |
| Publication Date: | 2009 |
| Country: | Brasil |
| Institution: | Universidade Federal de São Paulo (UNIFESP) |
| Repository: | Repositório Institucional da UNIFESP |
| Language: | Portuguese |
| OAI Identifier: | oai:repositorio.unifesp.br:11600/9842 |
| Online Access: | http://repositorio.unifesp.br/handle/11600/9842 |
| Access Level: | Open access |
| Keyword: | Exercise test Anaerobic threshold Myocardial ischemia Coronary artery disease Technetium Tc 99m Sestamibi Teste de esforço Limiar anaeróbio Isquemia miocárdica Doença da artéria coronariana Tecnécio Tc 99m Sestamibi |
| Summary: | Background: Myocardial ischemia may occur during an exercise session in cardiac rehabilitation programs. However, it has not been established whether it is elicited when exercise prescription is based on heart rate corresponding to the anaerobic threshold as measured by cardiopulmonary exercise testing. Objectives: To assess the incidence of myocardial ischemia in cardiac rehabilitation programs according to myocardial perfusion SPECT in exercise programs based on the anaerobic threshold. Methods: Thirty-nine patients (35 men and 4 women) diagnosed with coronary artery disease by coronary angiography and stress technetium-99msestamibi gated SPECT associated with a baseline cardiopulmonary exercise test were assessed. Ages ranged from 45 to 75 years. A second cardiopulmonary exercise testing determined training intensity at the anaerobic threshold. Repeat gated-SPECT was obtained after a third cardiopulmonary exercise testing at the prescribed workload and heart rate. Results: Myocardial perfusion images, analyzed using a score system: 6.4 at rest, 13.9 at peak stress, and 10.7 during the prescribed exercise (p<0.05). The presence of myocardial ischemia during exercise was defined as a difference ³ 2 between the summed stress score and summed rest score. Accordingly, 25 (64%) patients were classified as ischemic and 14 (36%) as nonischemic. Conclusion: MIBI-SPECT has shown myocardial ischemia during exercise within the anaerobic threshold. The 64% prevalence of ischemia observed in the study should not be looked on as representative of the whole population of patients undergoing exercise program. The changes in patient care and exercise program were implemented as a result of our findings (ischemia during the prescribed exercise). |
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