Validação de um método de medição da frequência cardíaca de repouso

Abstract

Chronic non-communicable diseases (CNCDs) are the main causes of morbidity and mortality in the world population, responsible for more than 70% of deaths in Brazil, with the main causes being cardiovascular diseases (CVD). High resting heart rate (RHR) can be considered a risk factor for CVD and non-cardiovascular diseases, in addition to being associated with general mortality. RHR is characterized by ease of operation, low cost and important prognostic information, but it does not have a standardized and valid measurement method. This was evidenced through an integrative review, which reviewed 25 articles from the MEDLINE, SCIELO and LILACS databases, considering 6 criteria for evaluation: Pre-measurement care; Resting time before measurement; Body posture; Environmental conditions at the test site; Measurement method; Data analysis. The results showed the lack of a standard and valid method for measuring RHR. This validation could contribute to improving the quality and efficiency of services in the Unified Health System (SUS). The present study sought to validate a method for measuring RHR, through radial palpation (RP) compared with the heart rate monitor (HRM). Fifty-seven adult individuals (31 men 48.1 ± 15.3; 26 women 51.2 ± 13.5), apparently healthy, were evaluated for three days over a maximum period of one week. The individuals were guided, in the days before the assessments, with pre-test care, such as dietary precautions, substances, exercise and excesses that could interfere with the measurements. The measurements were carried out by two evaluators, each one was responsible for one day of evaluation, with one of the evaluators measuring the individual twice and the other measuring once, such measurements were carried out randomly. To validate the method, the data were analyzed using descriptive statistics, Bland Altman plots, intraclass correlation coefficients (ICC) and variance components analysis (VCA). The mean RHR of HRM individuals was 69.1 ± 9.9 for men and 72.2 ± 11.4 for women and PR 68.8 ± 9.7 for men and 71.8 ± 11.3 for women. The average difference between the methods was less than one beat (0.34 ± 0.99) and the correlation between the methods generated an r2 = 0.991. Other analyzes carried out comparing measurements by day and by evaluators showed small differences, all of which were less than 1 beat. Inter-rater reliability, analyzed by the intraclass correlation coefficient (ICC), generated moderate intra-rater 1 (0.698) and good intra-rater 2 (0.862) ratings. Between raters, the coefficients were all good (ICC >0.7), indicating good agreement between raters. When analyzing the variance of the RHR data, it was possible to verify that the largest difference is between individuals, 80.9%. We can verify that the RHR can be measured by the established protocol, using the PR, which proved to be in agreement with the HRM and reliable for use between evaluators, and can be easily implemented in health services, due to its great accessibility, easy handling, low need for training of evaluators and great clinical importance of its use.