1994 Fiscal Year Final Research Report Summary

Study of DFT energy during ICD implant

Research Project

Project/Area Number	05671142
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	Thoracic surgery
Research Institution	NIPPON MEDICAL SCHOOL
Principal Investigator	TANAKA Shigeo 2nd Dept.of Surgery, Nippon Med.School, Prof., 医学部, 教授 (70089720)
Co-Investigator(Kenkyū-buntansha)	UTSUNOMIYA Hidetoshi 2nd Dept.of Surgery, Nippon Med.School, Clinical Fellow, 医学部 (70176709) ASANO Tetuso 2nd Dept.of Surgery, Nippon Med.School, Associate Prof., 医学部, 助教授 (10150731) IKESHITA Masatoshi 2nd Dept.of Surgery, Nippon Medical, Associate Prof., 医学部, 助教授 (20089725)
Project Period (FY)	1993 – 1994
Keywords	Implantable Cardioverter Defibrillator / Defibrillation Threshold Test / DFL,ULV
Research Abstract	It is necessary to measure defibrillation threshold (DFT) during implantation of the implantable cardioverter defibrillator (ICD). Determination of DFT requires repeated induction of ventricular fibrillation and defibrillation attempts using high-enrergy shocks. These may lead to cerebral ischemia and myocardial damage. In recent studies, uppper limit of vulnerability (ULV) has been shown to closely correlate with DFT in aminal models. We examined whether ULV is present in human and whether ULV can be used to accurately predict DFT during implantation of ICD. We underwent the ICD implantation for life-threatening ventricular arrhythmia. During the implantation, the shock strength associated with a 50% probabirity of reaching ULV (ULV50) and a 50% probabirity of reaching DFT (DFT50) were determined by the delayd four-episode up down algorithm. ULV existed in each cases. ULV50 was 3.8 <plus-minus> 2.0J and DFT50 was 6.5 <plus-minus> 4.9J.The correlation between ULV50 and DFT50 is signific (r=0.99, P<0.0001, DFT50=-2.97*2.45ULV50) Conclution : Measurement of UVL can be used as a substitutes for measurement of DFT during implantation of ICD,and significantly reduce the number of. VF induction and shock required to determinarion of DFT. Therefore, we are thinking to analyze the mechanism of defibrillation using multi-channel mapping device.