NONTHORACOTOMY IMPLANTATION OF CARDIOVERTER-DEFIBRILLATORS - PRELIMINARY EXPERIENCE WITH A DEFIBRILLATION LEAD PLACED AT THE RIGHT-VENTRICULAR OUTFLOW TRACT

Although morbidity and mortality associated with defibrillator implant ation using a nonthoracotomy approach have decreased as compared nifh a thoracotomy approach, defibrillation thresholds have been higher and fewer patients satisfied implant criteria. If may be possible to impr ove on the success of nonthoracotomy defibrillator implantation by the placement of a right ventricular (RV) outflow defibrillation lead, Im plantable cardioverter defibrillator implantation data of 30 consecuti ve patients with clinical VT or VF were reviewed. Three defibrillation leads were routinely used. When either pacing threshold at the RV ape x was inadequate (n = 2) or 18-J-shocks rt ere not-successful in termi nating VF in 3 of 4 trials (n = 8), the RV apex lead was positioned to the RV outflow tract attaching to the septum. Defibrillation testing was first performed with the RV apex lead in combination with CS, SVC, and/or subcutaneous leads. Twenty patients satisfied implant criteria with a defibrillation threshold of 13.5 +/- 3.6 J. In 7 of the 10 pat ients, whose RV lead was repositioned to the RV outflow tract, this le ad in combination with SVC, CS, or subcutaneous leads produced success ful defibrillation at less than or equal to 18 J or in 3 of 4 trials, This approach improved the overall success of nonthoracotomy implantat ion of defibrillators from 69% to 90%. After a follow-up of 27 +/- 6 m onths, there was no dislodgment-of the RV outflow tract defibrillation leads. Conclusions: This article reports the preliminary observation that placement of defibrillation leads to the RV outflow tract in huma ns was possible and without dislodgment. RV outflow tract offers an al ternative for placement of defibrillation leads, which may improve on the success of nonthoracotomy defibrillator implantation.