title: Single-Coil Defibrillator Leads Yield Satisfactory Defibrillation Safety Margin in Hypertrophic Cardiomyopathy.
abstract: BACKGROUND
  Single-coil defibrillator leads have gained favor because of their potential ease of extraction. However, a high defibrillation threshold remains a concern in patients with hypertrophic cardiomyopathy (HCM), and in many cases, dual-coil leads have been used for this patient group. There is little data on using single-coil leads for HCM patients.
  
  
  RESULTS
  We evaluated 20 patients with HCM who received an implantable cardioverter-defibrillator (ICD) on the left side in combination with a dual-coil lead. Two sets of defibrillation tests were performed in each patient, one with the superior vena cava (SVC) coil "on" and one with the SVC coil "off". ICDs were programmed to deliver 25 joules (J) for the first attempt followed by maximum energy (35 J or 40 J). Shock impedance and shock pulse width at 25 J in each setting as well as the results of the shock were analyzed. All 25-J shocks in both settings successfully terminated ventricular fibrillation. However, shock impedance and pulse width increased substantially with the SVC coil programmed "off" compared with "on" (66.4±6.1 ohm and 14.0±1.3 ms "off" vs. 41.9±5.0 ohm and 9.3±0.8 ms "on", P<0.0001 respectively).
  
  
  CONCLUSIONS
  Biphasic 25-J shocks with the SVC coil 'off' successfully terminated ventricular fibrillation in HCM patients, indicating a satisfactory safety margin for 35-J devices. Single-coil leads appear appropriate for left-sided implantation in this patient group. (Circ J 2016; 80: 2199-2203).
authors: Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center.
authors: Hideo
authors: H
authors: Okamura
authors: Paul A
authors: PA
authors: Friedman
authors: Yuko
authors: Y
authors: Inoue
authors: Takashi
authors: T
authors: Noda
authors: Takeshi
authors: T
authors: Aiba
authors: Satoshi
authors: S
authors: Yasuda
authors: Hisao
authors: H
authors: Ogawa
authors: Shiro
authors: S
authors: Kamakura
authors: Kengo
authors: K
authors: Kusano
authors: Raul E
authors: RE
authors: Espinosa
mesh_terms: D000368:Aged; D002312:Cardiomyopathy, Hypertrophic / Q000503:physiopathology / Q000628:therapy*; D017147:Defibrillators, Implantable; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012449:Safety; D014693:Ventricular Fibrillation / Q000503:physiopathology / Q000628:therapy*