Abstract

GUTIERREZ SOTELO, Oswaldo; POUTVINSKY, Vladimir; ROMERO, Luis  and  ESQUIVEL, Lidieth. Variabilidad de la frecuencia cardíaca en pacientes con angina inestable: correlación con otros marcadores pronósticos. Rev. costarric. cardiol [online]. 2004, vol.6, n.1, pp.7-12. ISSN 1409-4142.

Introduction: The usefullness of heart rate variability (HRV) analysis is well known in myocardial infarction as in other cardiac diseases as a prognostic tool. The primary goal of this study is to determine HRV relationship with other prognostic markers in unstable angina patients. Materials and methods: We studied prospectively patients with diagnosis of unstable angina. We considered predictors of cardiovascular risk (unresponsive rest angina, hipotension, heart failure, dynamic ST changes, ejection fraction less than 40% and angiographic features (2 or more vessels), conforming two groups, high risk and low risk. In every patient was made a 5 minute electrocardiographic recording and we analysed HRV variables in time domain and frequency domain. All this variables were compared between both groups Results: We included 63 patients (44 males, 70%) with mean age 63 + 10.4 years old (35-90); 46 were considered of high risk because dynamic ST changes and depressed ejection fraction and the remaining 17 were considered at low risk. In the first group, total spectral power was statistically different (p=0.04) compared with low-risk group. Low frequency band (LF) was also different but without statistic significance (p=0.07) and other variables like SDNN, NN5 0 and low frequency showed only a trend to be less in the high-risk group. Conclusion: Clinical high-risk patients with unstable angina have low HRV variables. This feature could be predictive of poor survival in follow-up prospective studies.

Keywords : Variabilidad; frecuencia cardíaca; angina inestable.