Increase in internal defibrillation threshold during acute myocardial infarction.
A 67-year-old man suffered an acute anteroseptal myocardial infarction complicated by multiple episodes of ventricular fibrillation, which were not systematically defibrillated by maximum, internal 35-J shocks delivered by an implanted cardioverter defibrillator (ICD). He had suffered from acute inferior myocardial infarction 6 years earlier, complicated with sustained polymorphic ventricular tachycardia (VT). Due to inducibility of sustained VT on an electrophysiologic study, an ICD was implanted. Defibrillation testing performed after healing of anteroseptal infarction was successful with a 10-J safety margin, suggesting that acute myocardial ischemia transiently elevated the internal defibrillation threshold.
Ota
Masaki
M
Department of Medicine and Biological Science, Gunma University Graduate School of Medicine, Maebashi.
Kaneko
Yoshiaki
Y
Nakajima
Tadashi
T
Saito
Akihiro
A
Irie
Tadanobu
T
Kato
Toshimitsu
T
Iijima
Takafumi
T
Ito
Toshio
T
Manita
Mamoru
M
Kurabayashi
Masahiko
M
D000368:Aged; D017147:Defibrillators, Implantable; D004562:Electrocardiography; D006801:Humans; D008297:Male; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000503:physiopathology* / Q000628:therapy