RESUMO
The correlation between R wave voltage variations (delta R) and the angiographic severity of coronary artery disease (CAD) at progressively increasing heart rate (HR) steps was evaluated in 51 patients (pts) without CAD (OV), in 42 pts with single (SVD), in 43 with double (DVD) and in 59 pts with triple vessel disease (TVD). At the end of stress the sensitivity of delta R was higher in DVD and TVD pts than in SVD pts. There was no clear correlation between exercise-induced R wave changes and the angiographic severity of CAD, since the qualitative and quantitative delta R evaluation during effort showed similar changes in delta R for a wide range of HR's in the entire study population. Since different degrees of exercise tolerance were found in pts with SVD, DVD and TVD, we hypothesize that the correlation between delta R and the severity of CAD at the end of stress testing may be artifactual.
Assuntos
Doença das Coronárias/fisiopatologia , Eletrocardiografia , Frequência Cardíaca , Esforço Físico , Análise de Variância , Angiografia Coronária , Doença das Coronárias/diagnóstico por imagem , Reações Falso-Negativas , Reações Falso-Positivas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estatística como AssuntoAssuntos
Angina Pectoris/terapia , Ponte de Artéria Coronária , Doença das Coronárias/cirurgia , Adulto , Idoso , Angina Pectoris/classificação , Ponte de Artéria Coronária/efeitos adversos , Estudos de Avaliação como Assunto , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/etiologiaRESUMO
In order to study whether different heart rates achieved at peak exercise by normal subjects and patients with coronary artery disease (CAD) affect the results of analysis of R-wave amplitude changes (delta R), we evaluated delta R at progressively increasing heart rate (HR) steps in 60 normal subjects with negative exercise tests (ET), in 130 patients with CAD, in 88 patients with true positive and 42 with false negative ET, and in 43 patients with no CAD and false positive ET. We found that the sensitivity and specificity of delta R were HR dependent, the former decreasing and the latter increasing with progressively increasing HR steps. Mean values of delta R did not discriminate among the four groups for HRs up to 150 bpm; significant differences were found between normal subjects and CAD patients, both with true positive and false negative stress tests, at HR greater than 150 bpm. False positive patients had mean delta R similar to those found in normal subjects. We hypothesize that quantitative delta R analysis could be useful in ECG diagnosis of false negative and false positive patients at HR greater than 150 bpm.
