competitive athletes with implantable cardioverterdefibrillatorshow to program data from the implantable cardioverterdefibrillator sports registry background athletes with an implantable cardioverterdefibrillator icd may require unique optimal devicebased tachycardia programmingobjective the purpose of this study was to assess the association of tachycardia programming characteristics of icds with occurrence of shocks transient lossofconsciousness and death among athletesmethods a subanalysis of a prospective observational international registry of 440 athletes with icds followed for a median of 44 months was performed programming characteristics were divided into groups for rate cutoff very high high or low and detection longdetection interval nominal or nominal endpoints included total appropriate and inappropriate shocks transient lossofconsciousness and mortalityresults in this cohort 62 were programmed with highrate cutoff and 30 with long detection no athlete died of an arrhythmia related or unrelated to icd shocks three patients had sustained ventricular tachycardia below programmed detection rate presenting as palpations andor dizziness icd shocks were received by 98 athletes 64 appropriate 32 inappropriate 2 patients received both programming a highrate cutoff was associated with decreased risk of total p 01 and inappropriate p 04 shocks overall and during competition or practice programming longdetection intervals was associated with fewer total shocks single vs dualchamber devices and the number of zones were unrelated to risk of shock transient lossofconsciousness associated with 27 appropriate shocks was not related to programming characteristicsconclusion highrate cutoff and longdetection duration programming of icds in athletes at risk for sudden death can reduce total and inappropriate icd shocks without affecting survival or the incidence of transient lossofconsciousness