title: [Influence of increased mean heart rate at rest on mortality and ventricular tachycardia resulting in adequate intervention in patients after implantable cardioverter-defibrillator implantation].
abstract: BACKGROUND
  Increased heart rate at rest (HR) is a risk factor of sudden cardiac death (SCD) and cardiovascular mortality.
  
  
  OBJECTIVE
  Retrospective assessment of increased HR influence on mortality and ventricular tachycardia followed by adequate ICD intervention.
  
  
  METHODS
  350 patients (52 female, 298 male), mean age 65.1+/-10.1 years (22-89 years) with ICD without resynchronization function implanted between 2008 and 2010 were examined. ECGs at rest were used to determine HR. In case of atrial fibrillation, mean value of 2 shortest and longest RR intervals was calculated to determine HR.
  
  
  RESULTS
  During the mean observation period of 387+/-300 days, 73 patients (66 male, 7 female), mean age 63.7+/-12.2 years (22-89) had an arrhythmial/intervention, and 46 patients (9 male, 37 feamle), mean age 68.8+/-10.3 years (43-86) died. To optimize sensitivity and specificity of HR, cut off point was established using ROC curve (79/min). Number of patients with HR>79/min was significantly higher (64.7% vs 19,1%, p<0.022) in the group of patients with arrhyth-mialintervention vs no arrhythmial/intervention, and in dead vs alive patients (73.9% vs 19.5%, p<0,001). Kaplan-Meier univariate analysis proved, that HR<or =79/min was an important factor increasing probability of survival (p<0.001) and arrhythmial/intervention free live (p<0.012). HR>79/ min particularly predisposed to fast ventricular arrhythmias and interventions - CV (p<0.092). In Cox multivariate analysis, HR< or =79/min was a protective factor only in death risk (HR=0.2362, 95%CI=0.1094-0.5099, p<0.0002).
  
  
  CONCLUSIONS
  An important factor increasing probability of survival without ventricular arrhythmia or death was a mean heart rate below 79/min. The cycle length of the baseline rhythm determine the arrhythmia cycle length.
authors: Uniwersytet Jagiellońiski, Instytut Kardiologii, Klinika Elektrokardiologii, Krakowski Szpital Specjalistyczny im. Jana Pawła II. jlelakow@szpitaljp2.krakow.pl
authors: Jacek
authors: J
authors: Lelakowski
authors: Anna
authors: A
authors: Rydlewska
authors: Jacek
authors: J
authors: Majewski
authors: Jacek
authors: J
authors: Bednarek
authors: Andrzej
authors: A
authors: Zabek
authors: Barbara
authors: B
authors: Małecka
authors: Joanna
authors: J
authors: Pudło
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002318:Cardiovascular Diseases / Q000175:diagnosis* / Q000401:mortality* / Q000628:therapy; D015984:Causality; D016757:Death, Sudden, Cardiac / Q000453:epidemiology*; D017147:Defibrillators, Implantable / Q000706:statistics & numerical data*; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D017180:Tachycardia, Ventricular / Q000453:epidemiology*; D055815:Young Adult