BACKGROUND The goal of the present study was to determine the predictive value of beat-to-beat QT variability in heart failure patients across the continuum of left ventricular dysfunction. METHODS AND RESULTS Beat-to-beat QT variability index (QTVI), log-transformed heart rate variance, normalized QT variance, and coherence between heart rate variability… (More)
BACKGROUND Recently we showed the predictive value of sum absolute QRST integral (SAI QRST) and repolarization lability for risk stratification of sudden cardiac death (SCD) in heart failure patients. The goal of this study was to compare SAI QRST and metrics of depolarization and repolarization variability in healthy men and women. METHODS Orthogonal… (More)
BACKGROUND Post-myocardial infarction (MI) structural remodeling is characterized by left ventricular dilatation, fibrosis, and hypertrophy of the non-infarcted myocardium. OBJECTIVE The goal of our study was to quantify post-MI electrical remodeling by measuring the sum absolute QRST integral (SAI QRST). We hypothesized that adverse electrical remodeling… (More)
BACKGROUND Despite advances in prevention and treatment of cardiovascular disease, sudden cardiac death (SCD) remains a clinical challenge. Risk stratification in the general population is needed. METHODS AND RESULTS Beat-to-beat spatiotemporal variability in the T vector was measured as the mean angle between consecutive T-wave vectors (mean TT' angle)… (More)
Microarray measurements of gene expression constitute a large fraction of publicly shared biological data, and are available in the Gene Expression Omnibus (GEO). Many studies use GEO data to shape hypotheses and improve statistical power. Within GEO, the Affymetrix HG-U133A and HG-U133 Plus 2.0 are the two most commonly used microarray platforms for human… (More)
The steady rise in healthcare costs has deprived over 45 million Americans of healthcare services (1, 2) and has encouraged healthcare providers to look for opportunities to improve their operational efficiency. Prior studies have shown that evidence of healthcare seeking intent in Internet searches correlates well with healthcare resource utilization.… (More)
BLOCKIN neighbors on a time interval of 60 days was found to be the highest performing based on a F1 measure of nearly 0.7, specificity of 0.51, and training and test errors of roughly 0.35, demonstrating that this still remains a challenging problem in time series classification.