title: A novel heart rate variability algorithm for the detection of myocardial ischemia: pilot data from a prospective clinical trial.
abstract: BACKGROUND
  Heart rate variability (HRV) analysis has been shown to be a predictor of sudden cardiac death and all-cause mortality in patients with cardiac disease.
  
  
  OBJECTIVE
  To examine whether newer HRV analysis algorithms, as used by the HeartTrends device, are superior to exercise stress testing (EST) for the detection of myocardial ischemia in patients without known coronary artery disease (CAD).
  
  
  METHODS
  We present pilot data of the first 100 subjects enrolled in a clinical trial designed to evaluate the yield of short-term (1 hour) HRV testing for the detection of myocardial ischemia. The study population comprised subjects without known CAD referred to a tertiary medical center for EST with single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI). All patients underwent a 1 hour electrocardiographic acquisition for HRV analysis with a HeartTrends device prior to ESTwith MPI. Sensitivity, specificity, and positive and negative predictive values (PPV and NPV, respectively) were calculated for EST and HRV analysis, using MPI as the gold standard for the non-invasive detection of myocardial ischemia.
  
  
  RESULTS
  In this cohort 15% had a pathologic MPI result. HRV analysis showed superior sensitivity (85%), PPV (50%) and NPV (97%) as compared to standard EST (53%, 42%, 90%, respectively), while the specificity of the two tests was similar (86% and 85%, respectively). The close agreement between HRV and MPI was even more pronounced among patients > 65 years of age.
  
  
  CONCLUSIONS
  Our pilot data suggest that the diagnostic yield of the novel HeartTrends HRV algorithm is superior to conventional EST for the non-invasive detection of myocardial ischemia.
authors.forename: Dan
authors.initials: D
authors.lastname: Oieru
authors.forename: Israel
authors.initials: I
authors.lastname: Moalem
authors.forename: Eli
authors.initials: E
authors.lastname: Rozen
authors.forename: Alexey
authors.initials: A
authors.lastname: Naimushin
authors.forename: Robert
authors.initials: R
authors.lastname: Klempfner
authors.forename: Ilan
authors.initials: I
authors.lastname: Goldenberg
authors.forename: Ronen
authors.initials: R
authors.lastname: Goldkorn
mesh_terms: D000328:Adult; D000465:Algorithms; D000704:Analysis of Variance; D005260:Female; D006339:Heart Rate; D006801:Humans; D007557:Israel; D008297:Male; D017202:Myocardial Ischemia / Q000175:diagnosis / Q000503:physiopathology; D055414:Myocardial Perfusion Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon