Publicação

Frequência cardíaca durante a prova de esforço e sua relação com o prognóstico

Detalhes bibliográficos
Resumo:	I. INTRODUCTION Functional capacity, arterial blood pressure variations, chronotropic evolution and development of arrhythmia during and after the exercise test have revealed increasing significance in stratifying the risk of coronary artery disease. Chronotropic incompetence seems to be related to more severe coronary artery disease, left ventricular dysfunction, sinoatrial or atrioventricular node dysfunction and anomalies in the autonomic nervous system. Consequently, it’s related to an increased cardiovascular mortality and worse prognosis. II. GOALS This study aims to evaluate the prognosis value of the heart rate variations in the exercise test and its correlation with the development of electrocardiographic markers of ischemia. III. METHODOLOGY This was a longitudinal retrospective study that included 183 patients with coronary heart disease (history of myocardial infarction and/or myocardial revascularization), 49 of them under β-blocker therapy, witch realized exercise test by the Bruce protocol in 2006, in the Cardiology department of the Coimbra University Hospital. The exclusion criteria were: exercise test to estimate functional capacity, to evaluate arrhythmia or to study suspected coronary artery disease. The group was characterized according to gender, age, body mass index, β-blocker therapy, resting heart rate and resting double product. The following parameters were analyzed: exercise duration, METs achieved, resting and stress double product, maximal heart rate, heart rate reserve, percentage of maximal heart rate predicted for age, basal heart rate recovery and heart rate recovery at the first minute, ST segment depression and angor. Follow-up lasted until the end of 2009 or until a cardiovascular event. IV. RESULTS The studied patients were mainly men (90.2%) with a mean age of 60.0 years (SD ± 10.9). 26.8% of the patients were under β-blocker therapy. 61.7% of the tests were submaximal. 14.2% of the patients developed ST depression and 7.7% reported angor under stress. ST depression was significantly related to angor (p ≤ 0.001) and to basal heart rate recovery (p ≤ 0.001). During follow-up, 25 cardiovascular events were reported. Heart rate reserve (p ≤ 0.05) and submaximal exercise test (p ≤ 0.05) were significantly related to the development of cardiovascular events. The percentage of maximal predicted heart rate, the percentage of heart rate reserve used and chronotropic incompetence had prognostic value (p ≤ 0.05). V. CONCLUSIONS Heart rate variation and particularly chronotropic incompetence during the exercise test seemed to be related with events in patients with coronary artery disease. The routine implementation of heart rate analysis could help to select a group of higher risk patients that could benefit from a more aggressive approach.
Autores principais:	Prelhaz, Ana Carolina Figueira
Assunto:	Isquemia miocárdica Prova de esforço Frequência cardíaca Prognóstico
Ano:	2011
País:	Portugal
Tipo de documento:	dissertação de mestrado
Tipo de acesso:	acesso aberto
Instituição associada:	Universidade de Coimbra
Idioma:	português
Origem:	Estudo Geral - Universidade de Coimbra

Descrição
Resumo:	I. INTRODUCTION Functional capacity, arterial blood pressure variations, chronotropic evolution and development of arrhythmia during and after the exercise test have revealed increasing significance in stratifying the risk of coronary artery disease. Chronotropic incompetence seems to be related to more severe coronary artery disease, left ventricular dysfunction, sinoatrial or atrioventricular node dysfunction and anomalies in the autonomic nervous system. Consequently, it’s related to an increased cardiovascular mortality and worse prognosis. II. GOALS This study aims to evaluate the prognosis value of the heart rate variations in the exercise test and its correlation with the development of electrocardiographic markers of ischemia. III. METHODOLOGY This was a longitudinal retrospective study that included 183 patients with coronary heart disease (history of myocardial infarction and/or myocardial revascularization), 49 of them under β-blocker therapy, witch realized exercise test by the Bruce protocol in 2006, in the Cardiology department of the Coimbra University Hospital. The exclusion criteria were: exercise test to estimate functional capacity, to evaluate arrhythmia or to study suspected coronary artery disease. The group was characterized according to gender, age, body mass index, β-blocker therapy, resting heart rate and resting double product. The following parameters were analyzed: exercise duration, METs achieved, resting and stress double product, maximal heart rate, heart rate reserve, percentage of maximal heart rate predicted for age, basal heart rate recovery and heart rate recovery at the first minute, ST segment depression and angor. Follow-up lasted until the end of 2009 or until a cardiovascular event. IV. RESULTS The studied patients were mainly men (90.2%) with a mean age of 60.0 years (SD ± 10.9). 26.8% of the patients were under β-blocker therapy. 61.7% of the tests were submaximal. 14.2% of the patients developed ST depression and 7.7% reported angor under stress. ST depression was significantly related to angor (p ≤ 0.001) and to basal heart rate recovery (p ≤ 0.001). During follow-up, 25 cardiovascular events were reported. Heart rate reserve (p ≤ 0.05) and submaximal exercise test (p ≤ 0.05) were significantly related to the development of cardiovascular events. The percentage of maximal predicted heart rate, the percentage of heart rate reserve used and chronotropic incompetence had prognostic value (p ≤ 0.05). V. CONCLUSIONS Heart rate variation and particularly chronotropic incompetence during the exercise test seemed to be related with events in patients with coronary artery disease. The routine implementation of heart rate analysis could help to select a group of higher risk patients that could benefit from a more aggressive approach.