Influence of body position on defibrillation thresholds of nonthoracotomy implantable defibrillators: a prospective randomized evaluation.

摘要: DFT of Nonthoracotomy Defibrillators. Introduction: Defibrillation thresholds (DFTs) usually are determined with the patient in supine position. However, patients may be upright position when a shock is delivered during follow-up, which explain some first failures observed clinically. This study investigated whether body posture affects defibrillation energy requirements nonthoracotomy implantable cardioverter defibrillators biphasic shocks. Methods and Results: Using step up-down protocol, DFTs were compared intraindividually 52 (“active-can” systems 41 patients, two-lead II patients) for positions as achieved by tilt table. The mean was 7.3 ± 4.2 J versus 9.2 4.8 (P = 0.002). Repeated comparison reversed order 3 months after implantation 22 revealed 6.2 2.5 (supine) 8.4 3.7 (upright; P < 0.03) 1 week 4.4 2.4 4.1 0.04) implantation. decreased significantly both from to 0.04). Conclusion:(I) shocks higher (2) Differences remain significant For positions, decreases These findings have important implications programming lower than maximal values or development devices stored energy.