title: The Effects of Shock from Defibrillation Threshold Testing on Cardiac Systolic and Diastolic Function.
abstract: BACKGROUND
  Inappropriate implantable cardioverter defibrillator (ICD) shocks are associated with increased overall mortality. However, it remains unclear whether shocks from defibrillation threshold (DFT) testing directly impair cardiac function.
  
  
  METHODS
  DFT testing was performed in 34 patients who underwent ICD/cardiac resynchronization therapy with a defibrillator implantation/generator exchange. Heart rate and cardiac function, including left ventricular (LV) systolic pressure, LV end-diastolic pressure, peak positive and negative dp/dt ( + dp/dt and -dp/dt, respectively) of LV pressure, and the tau index, were assessed with a Mikro-Cath™ diagnostic pressure catheter (CD Leycom, Zoetermeer, the Netherlands). These parameters were measured before and 1 minute, 3 minutes, 5 minutes, 10 minutes, and 15 minutes after DFT testing.
  
  
  RESULTS
  Peak positive dp/dt increased over baseline at each interval (976 ± 229 mm Hg/s vs 1,039 ± 258, 1,049 ± 245, 1,042 ± 247, 1,037 ± 259, and 1,034 ± 254 mm Hg/s, respectively; P < 0.01). Furthermore, peak negative dp/dt (-1,140 ± 397 mm Hg/s vs -1,185 ± 447, 1,193 ± 435, -1,195 ± 434, -1,189 ± 449, and -1,186 ± 459 mm Hg/s, respectively; P < 0.01) and the tau index (65.1 ± 18.5 vs 62.5 ± 16.8*, 62.4 ± 15.9(**) , 63.0 ± 16.8*, and 62.8 ± 18.7*, respectively; *P < 0.05, (**) P < 0.01) decreased compared to those at baseline at each interval.
  
  
  CONCLUSIONS
  Shock after DFT testing improved LV systolic and diastolic function immediately, especially in patients with preserved LV ejection fraction.
authors.affiliation: Cardiovascular Division, Department of Internal Medicine, Hyogo College of Medicine, Nishinomiya, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kodani
authors.affiliation: Cardiovascular Division, Department of Internal Medicine, Hyogo College of Medicine, Nishinomiya, Japan. mine@hyo-med.ac.jp.
authors.forename: Takanao
authors.initials: T
authors.lastname: Mine
authors.affiliation: Cardiovascular Division, Department of Internal Medicine, Hyogo College of Medicine, Nishinomiya, Japan.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Kishima
authors.affiliation: Cardiovascular Division, Department of Internal Medicine, Hyogo College of Medicine, Nishinomiya, Japan.
authors.forename: Tohru
authors.initials: T
authors.lastname: Masuyama
mesh_terms: D017147:Defibrillators, Implantable / Q000009:adverse effects*; D004556:Electric Injuries / Q000175:diagnosis* / Q000209:etiology*; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013318:Stroke Volume; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis* / Q000209:etiology*
keywords: diastolic function; implantable cardioverter defibrillator; internal shock; systolic function; ventricular fibrillation