Background To establish the chronic stability of defibrillation thresholds (DFTs) in a transvenous cardioverter/defibrillator (TCD) system, we studied 37 consecutive patients with TCD systems implanted for >6 months.Methods and Results DFT was measured by a step-down method at implant and 2 and 6 months later. The mean ejection fraction was 34.5±14.3%. Coronary artery disease with previous myocardial infarction was present in 31 patients. The mean DFT rose from 13.3 ±4.3 J at implant to 16.5 ±4.7 J at 2 months (P<.001) and 17.6±5.4 J at 6 months (P<.0001). ANOVA revealed a statistically significant rise in DFT over time (P<.0005). At 2 months, 25 patients had a rise in DFT, and 14 had a rise 25 J. The observed rise at 2 months persisted
Extracorporeal shock wave lithotripsy (ESWL) is frequently used for nephrolithiasis of the upper urinary tract. Because of the powerful shock wave and electromechanical forces created, this therapy has been contraindicated in the patient with an implantable cardioverter defibrillator (ICD). To determine whether or not ESWL affects ICD devices, we subjected ten devices to a full course of ESWL. The devices were then returned to the manufacturer to undergo bench analysis, which revealed no abnormalities in function. Additionally, one device was placed in the pathway of the shock wave, resulting in a discharge of the device despite a frequency of ESWL of 100 shocks/min (well below the rate cutoff of that device). Manufacturer analysis of this device, likewise, revealed no abnormalities even though the device had been exposed to the focal point of the shock wave. We conclude that contralateral ESWL is not contraindicated for the patient with an ICD. We do, however, recommend a post-procedure evaluation to ensure appropriate function of the ICD.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.