Applications of heart rate variability analysis in the stratification of arrhythmia risks in acute myocardial infarction

The study of heart rate variability in the frequency domain is currently considered a promising noninvasive method for the quantitative study of neurovegetative modulation of the heart rate. On the other hand, the risk of severe arrhythmias in the acute stage of infarcts during thrombolysis and the determinant role played in the appearance of arrhythmias by the neurovegetative system is well known. The authors´ objective here is the study of neurovegetative modulation during the first 6 hours of evolution of acute myocardial infarct in a Critical Care Unit (CCU) by means of the analysis of the spectral components of heart rate fluctuations. The preliminary results of the authors´ work show that the LF/HF and LF/(LF+HF) indices have statistically different evolutive profiles depending on the presence or absence of severe arrhythmias and that their determination in the first minutes after arrival in the CCU permits the discrimination of the patients that in the first 24 hours of evolution presented severe arrhythmias with a Sensitivity and Specificity of 71% and 100% respectively. If these results are confirmed in later studies, it is evident that one is at the threshold of an important application of this type of RR interval processing