CONCOMITANT AMIODARONE AND THE IMPLANTABLE CARDIOVERTER-DEFIBRILLATOR- IS THERE A PLACE

OBJECTIVE: To discuss the controversy surrounding concomitant therapy with amiodarone and the implantable cardioverter-defibrillator (ICD). DATA souRCEs: A MEDLINE search identified English-language literature sources, including nonhuman studies. STUDY SELECTION: Studies included those that specifically addressed the use of amiodarone plus the ICD as well as reviews of the ICD. DATA EXTRACTION: Studies were evaluated for design, type of defibrillation electrode or defibrillator, method of defibrillation, amiodarone loading and maintenance dosages, durati on of amiodarone therapy, and study endpoints. DATA SYNTHESIS: Because the ICD functions by delivering energy to depolarize a mass of myocar dium, concomitant use of antiarrhythmic agents that elevate the defibr illation threshold (DFT) beyond an ICD's energy capability may adverse ly effect patient outcome. Amiodarone has been shown to both increase and decrease the DFT. Trials examining the use of amiodarone plus the ICD have not provided strong evidence that amiodarone will decrease th e number of ICD discharges or favorably affect the mortality rate. Ami odarone is also expensive and toxic. Although the cost of the ICD is r elatively high, continuing improvements in battery life will decrease long-term costs. CONCLUSIONS: Controlled trials are required to substa ntiate the improved survival rate with the ICD and to determine the ro le of antiarrhythmic agents in conjunction with the device. At present , there are no data to support the combination of amiodarone and an IC D in terms of improved quality or duration of life.