Usefulness of the heart-rate variability complex for predicting cardiac mortality after acute myocardial infarction.

Background: Previous studies indicate that decreased heart-rate variability (HRV) is related to the risk of death in patients after acute myocardial infarction (AMI). However, the conventional indices of HRV have poor predictive value for mortality. Our aim was to develop novel predictive models based on support vector machine (SVM) to study the integrated features of HRV for improving risk stratification after AMI.

[Investigation of heart rate turbulence after atrial premature beats before onset of paroxysmal atrial fibrillation].

Objective: To discuss the clinical significance of heart rate turbulence (HRT) after atrial premature beats in accessing the temporal changes of vagus nerve before the onset of paroxysmal atrial fibrillation.

Methods: The HRT parameters: turbulence onset (TOA) and turbulence slope (TSA) after atrial premature impulses occurring 0 to 60 min before and after the onset of AF 56 patients with atrial fibrillation (AF). The heart rate variability (HRV) time domain parameter SDNN and the frequency-domain parameters, low frequency (LF), high frequency (HF), and LF/HF ratio were also analyzed.