Abstract
Aim: The purpose of this study is to clear what factor is determine the defibrillation threshold (DFT) and predict patient who have high DFT. Methods: We examined 178 patients who underwent ICD/CRT-D implantation between July 2007 and March 2011 in our institution. We excluded the patient of right side implantation, but included one dextrocardia. We defined High DFT group (64 patients, male 51) who needed over 15 J, and low DFT group (114 patients, male 91) who could defibrillate 10 J when they underwent DFT test. In High DFT group, 12 patients were ischemic cardiomyopathy (ICM) and 52 patients were non-ICM. In low DFT group, 27 patients were ICM and 87 patients were non-ICM, and we compared the left ventricular dimension of diastolic/systolic (LVDd/Ds) and left ventricular ejection fraction (LVEF) of High DFT group and low DFT group. LVDd/Ds and LVEF (modified Simpson method) was measured by echocardiography. Results: LVDs of High DFT group (43.6 mm ±16.1) was significant lower than that of low DFT group (38.1 mm ±12.2) (P=0.01), and LVEF of High DFT group (43.2 % ±17.7) was also significant higher than that of low DFT group (48.4 % ±15.8) (P=0.04). But, LVDd was not significant difference between High DFT group (54.6 mm ±13.4) and low DFT group (51.4 mm ±10.5) (P=0.08). Conclusion: We would like to emphasize that the assessment of LVDs and LVEF by echocardiography is useful for predicting of patient who tend to have high DFT.
