Open AccessHeart Rate Variability Density Analysis ( Dyx ) and Prediction of Long‐Term Mortality after Acute Myocardial Infarction
Author(s) -
Jørgensen Rikke Mørch,
Abildstrøm Steen Z.,
Levitan Jacob,
Kobo Roi,
Puzanov Natalia,
Lewkowicz Meir,
Huikuri Heikki,
Peltola Mirja,
Haarbo Jens,
Thomsen Poul Erik Bloch
Publication year - 2016
Publication title -
annals of noninvasive electrocardiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.494
H-Index - 48
eISSN - 1542-474X
pISSN - 1082-720X
DOI - 10.1111/anec.12297
Subject(s) - medicine , cardiology , myocardial infarction , heart rate variability , ejection fraction , heart failure , heart rate , blood pressure
Aims The density HRV parameter Dyx is a new heart rate variability (HRV) measure based on multipole analysis of the Poincaré plot obtained from RR interval time series, deriving information from both the time and frequency domain. Preliminary results have suggested that the parameter may provide new predictive information on mortality in survivors of acute myocardial infarction (MI). This study compares the prognostic significance of Dyx to that of traditional linear and nonlinear measures of HRV. Methods and results In the Nordic ICD pilot study, patients with an acute MI were screened with 2D echocardiography and 24‐hour Holter recordings. The study was designed to assess the power of several HRV measures to predict mortality. Dyx was tested in a subset of 206 consecutive Danish patients with analysable Holter recordings. After a median follow‐up of 8.5 years 70 patients had died. Of all traditional and multipole HRV parameters, reduced Dyx was the most powerful predictor of all‐cause mortality (HR 2.4; CI 1.5 to 3.8; P < 0.001). After adjustment for known risk markers, such as age, diabetes, ejection fraction, previous MI and hypertension, Dyx remained an independent predictor of mortality (P = 0.02). Reduced Dyx also predicted cardiovascular death (P < 0.01) and sudden cardiovascular death (P = 0.05). In Kaplan–Meier analysis, Dyx significantly predicted mortality in patients both with and without impaired left ventricular systolic function (P < 0.0001). Conclusion The new nonlinear HRV measure Dyx is a promising independent predictor of mortality in a long‐term follow‐up study of patients surviving a MI, irrespectively of left ventricular systolic function.