scholarly journals Survival Predictors of Heart Rate Variability After Myocardial Infarction With and Without Low Left Ventricular Ejection Fraction

2021 ◽  
Vol 15 ◽  
Author(s):  
Junichiro Hayano ◽  
Norihiro Ueda ◽  
Masaya Kisohara ◽  
Emi Yuda ◽  
Robert M. Carney ◽  
...  

BackgroundHeart rate variability (HRV) and heart rate (HR) dynamics are used to predict the survival probability of patients after acute myocardial infarction (AMI), but the association has been established in patients with mixed levels of left ventricular ejection fraction (LVEF).ObjectiveWe investigated whether the survival predictors of HRV and HR dynamics depend on LVEF after AMI.MethodsWe studied 687 post-AMI patients including 147 with LVEF ≤35% and 540 with LVEF >35%, of which 23 (16%) and 22 (4%) died during the 25 month follow-up period, respectively. None had an implanted cardioverter-defibrillator. From baseline 24 h ECG, the standard deviation (SDNN), root mean square of successive difference (rMSSD), percentage of successive difference >50 ms (pNN50) of normal-to-normal R-R interval, ultra-low (ULF), very-low (VLF), low (LF), and high (HF) frequency power, deceleration capacity (DC), short-term scaling exponent (α1), non-Gaussianity index (λ25s), and the amplitude of cyclic variation of HR (Acv) were calculated.ResultsThe predictors were categorized into three clusters; DC, SDNN, α1, ULF, VLF, LF, and Acv as Cluster 1, λ25s independently as Cluster 2, and rMSSD, pNN50, and HF as Cluster 3. In univariate analyses, mortality was best predicted by indices belonging to Cluster 1 regardless of LVEF. In multivariate analyses, however, mortality in patients with low LVEF was best predicted by the combinations of Cluster 1 predictors or Cluster 1 and 3 predictors, whereas in patients without low LVEF, it was best predicted by the combinations of Cluster 1 and 2 predictors.ConclusionThe mortality risk in post-AMI patients with low LVEF is predicted by indices reflecting decreased HRV or HR responsiveness and cardiac parasympathetic dysfunction, whereas in patients without low LVEF, the risk is predicted by a combination of indices that reflect decreased HRV or HR responsiveness and indicator that reflects abrupt large HR changes suggesting sympathetic involvement.

2021 ◽  
Author(s):  
Mohanad Alkhodari ◽  
Herbert F. Jelinek ◽  
Shiza Saleem ◽  
Leontios J. Hadjileontiadis ◽  
Ahsan H. Khandoker

Abstract Analysis of heart failure is important in clinical practice to ensure coronary artery disease (CAD) patients will be provided with appropriate timely treatment. The current gold standard, echocardiography, although reliable, provides a once-off left ventricular ejection fraction (LVEF) measurement but does not provide information about heart function the during day / night cardiac cycles. The aim of this study was to investigate the ability of heart rate variability (HRV) features in classifying CAD patients into multiple LVEF groups through a new index, HRV ejection fraction (HRVEF) and its agreement to established norms. A total of 92 heart failure patients were included in this study. HRVEF groups optimized on hourly basis through Jenks natural breaks algorithm exhibited a consistent pattern with a goodness of variance fit (GVF) of more than 0.70 accuracy during the late-night to early-morning (01:00-08:00) and evening (17:00-23:00) time periods. At these hours, several HRV features were found significant in differentiating between HRVEF groups using statistical analysis of variance (ANOVA) test. These features include the successive differences between normal heartbeats (RMSSD), low and high frequency (LF, HF) power, standard deviation of normal heartbeats (SD2), short-term scaling exponent (alpha1), and percentage of normal heartbeats in alternation segments (PAS). This study paves the way towards new LVEF guidelines based on the association between LVEF and HRV features for a better demonstration of the circadian cardiac function at different LVEF levels in CAD patients.


2016 ◽  
Vol 5 (1) ◽  
pp. 31 ◽  
Author(s):  
Konstantinos D Rizas ◽  
◽  
Wolfgang Hamm ◽  
Stefan Kääb ◽  
Georg Schmidt ◽  
...  

Periodic repolarisation dynamics (PRD) refers to low-frequency (≤0.1Hz) modulations of cardiac repolarisation instability. Spontaneous PRD can be assessed non-invasively from 3D high-resolution resting ECGs. Physiological and experimental studies have indicated that PRD correlates with efferent sympathetic nerve activity, which clusters in low-frequency bursts. PRD is increased by physiological provocations that lead to an enhancement of sympathetic activity, whereas it is suppressed by pharmacological b-blockade. Electrophysiological studies revealed that PRD occurs independently from heart rate variability. Increased PRD under resting conditions is a strong predictor of mortality in post-myocardial infarction (post-MI) patients, yielding independent prognostic value from left-ventricular ejection fraction (LVEF), heart rate variability, the Global Registry of Acute Coronary Events score and other established risk markers. The predictive value of PRD is particularly strong in post-MI patients with preserved LVEF (>35 %) in whom it identifies a new high-risk group of patients. The upcoming Implantable Cardiac Monitors in High-Risk Post-Infarction Patients with Cardiac Autonomic Dysfunction and Moderately Reduced Left Ventricular Ejection Fraction (SMART-MI) trial will test prophylactic strategies in high-risk post-MI patients with LVEF 36–50 % identified by PRD and deceleration capacity of heart rate (NCT02594488).


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