title: Quantitative analysis of ventricular ectopic beats in short-term RR interval recordings to predict imminent ventricular tachyarrhythmia.
abstract: BACKGROUND
  Most approaches to predict ventricular tachyarrhythmias which are based on RR intervals consider only sinus beats, excluding premature ventricular complexes (PVCs). The method known as heartprint, which analyses PVCs and their characteristics, has prognostic value for fatal arrhythmias on long recordings of RR intervals (>70,000 beats).
  
  
  OBJECTIVE
  To evaluate characteristics of PVCs from short term recordings (around 1000 beats) and their prognostic value for imminent sustained tachyarrhythmia.
  
  
  METHODS
  We analyzed 132 pairs of short term RR interval recordings (one before tachyarrhythmia and one control) obtained from 78 patients. Patients were classified into two groups based on the history of accelerated heart rate (HR) (HR>90bpm) before a tachyarrhythmia episode. Heartprint indexes, such as mean coupling interval (meanCI) and the number of occurrences of the most prevalent form of PVCs (SNIB) were calculated. The predictive value of all the indexes and of the combination of different indexes was calculated.
  
  
  RESULTS
  MeanCI shorter than 482ms and the occurrence of more repetitive arrhythmias (sNIB≥2.5), had a significant prognostic value for patients with accelerated heart rate: adjusted odds ratio of 2.63 (1.33-5.17) for meanCI and 2.28 (1.20-4.33) for sNIB. Combining these indexes increases the adjusted odds ratio: 10.94 (3.89-30.80).
  
  
  CONCLUSIONS
  High prevalence of repeating forms of PVCs and shorter CI are potentially useful risk markers of imminent ventricular tachyarrhythmia. Knowing if a patient has history of VT/VF preceded by accelerated HR, improves the prognostic value of these risk markers.
authors.affiliation: Departamento de Instrumentación Electromecánica, Instituto Nacional de Cardiología Ignacio Chávez, México, D.F. 14080, Mexico; Facultad de Ingeniería, Universidad Anáhuac, Huixquilucan, Estado de México 52786, Mexico.
authors.forename: Marisol
authors.initials: M
authors.lastname: Martínez-Alanis
authors.affiliation: Instituto de Investigaciones en Matemáticas Aplicadas y en Sistemas, Universidad Nacional Autónoma de México, México, D.F. 04510, Mexico.
authors.forename: Silvia
authors.initials: S
authors.lastname: Ruiz-Velasco
authors.affiliation: Departamento de Instrumentación Electromecánica, Instituto Nacional de Cardiología Ignacio Chávez, México, D.F. 14080, Mexico. Electronic address: dr.claudialerma@gmail.com.
authors.forename: Claudia
authors.initials: C
authors.lastname: Lerma
mesh_terms: D000368:Aged; D016208:Databases, Factual / Q000639:trends; D017147:Defibrillators, Implantable / Q000639:trends; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D017180:Tachycardia, Ventricular / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology*; D013997:Time Factors; D018879:Ventricular Premature Complexes / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology*
keywords: Coupling interval; Implantable cardioverter defibrillator; Premature ventricular complexes; Sudden cardiac death