title: Decreased Defibrillation Threshold and Minimized Myocardial Damage With Left Axilla Implantable Cardioverter Defibrillator Implantation.
abstract: BACKGROUND
  To reduce myocardial damage caused by implantable cardioverter defibrillator (ICD) shock, the left axilla was studied as an alternative pulse generator implantation site, and compared with the traditional implantation site, the left anterior chest.
  
  
  RESULTS
  Computer simulation was used to study the defibrillation conduction pattern and estimate the simulated defibrillation threshold (DFT) and myocardial damage when pulse generators were placed in the left axilla and left anterior chest, respectively; pulse generators were also newly implanted in the left axilla (n=30) and anterior chest (n=40) to compare the corresponding DFT. On simulation, when ICD generators were implanted in the left axilla, compared with the left anterior chest, the whole heart may be defibrillated with a lower defibrillation energy (left axilla 6.4 J vs. left anterior chest 12.0 J) and thus the proportion of cardiac myocardial damage may be reduced (2.1 vs. 4.2%). Clinically, ventricular fibrillation was successfully terminated with a defibrillation output ≤5 J in 86.7% (26/30) of the left axillary group, and in 27.5% (11/40) of the left anterior group (P<0.001).
  
  
  CONCLUSIONS
  Clinically and theoretically, the left axilla was shown to be an improved ICD implantation site that may reduce DFT and lessen myocardial damage due to shock. Lower DFT also facilitates less myocardial damage, as a result of the lower shock required.
authors.affiliation: Division of Cardiovascular Medicine, Toho University Ohashi Medical Center.
authors.forename: Mahito
authors.initials: M
authors.lastname: Noro
authors.forename: Xin
authors.initials: X
authors.lastname: Zhu
authors.forename: Yoshinari
authors.initials: Y
authors.lastname: Enomoto
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Oikawa
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tatsunami
authors.forename: Rina
authors.initials: R
authors.lastname: Ishii
authors.forename: Yasutake
authors.initials: Y
authors.lastname: Toyoda
authors.forename: Masako
authors.initials: M
authors.lastname: Asami
authors.forename: Naohiko
authors.initials: N
authors.lastname: Sahara
authors.forename: Takahito
authors.initials: T
authors.lastname: Takagi
authors.forename: Yuriko
authors.initials: Y
authors.lastname: Narabayashi
authors.forename: Hikari
authors.initials: H
authors.lastname: Hashimoto
authors.forename: Naoshi
authors.initials: N
authors.lastname: Ito
authors.forename: Shingo
authors.initials: S
authors.lastname: Kujime
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Sakai
authors.forename: Keijirou
authors.initials: K
authors.lastname: Nakamura
authors.forename: Takao
authors.initials: T
authors.lastname: Sakata
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Abe
authors.forename: Kaoru
authors.initials: K
authors.lastname: Sugi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001365:Axilla; D003198:Computer Simulation; D017147:Defibrillators, Implantable / Q000009:adverse effects*; D004554:Electric Countershock / Q000009:adverse effects / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D009206:Myocardium / Q000473:pathology*; D014693:Ventricular Fibrillation / Q000473:pathology / Q000503:physiopathology / Q000628:therapy