Fully transvenous cardioverter defibrillators: Rare need for subcutaneous patch with two newer-generation systems

Abstract

In published series of nonthoracotomy ICDs, there has invariably been a need for combining transvenous lead(s) with a subcutaneous patch to obtain adequate DFTs. Since the newer generation transvenous lead ICD systems became available for clinical investigation, we have tested and implanted 38 such systems in patients with drug-refractory malignant ventricular arrhythmias who were first seen with aborted sudden death ( n = 10), syncope ( n = 3), or sustained ventricular tachycardia ( n = 25). These patients (mean age 60 ± 15 years) had coronary artery disease ( n = 25), congenital heart disease ( n = 1), or cardiomyopathy ( n = 12) as the underlying heart disease and a mean left ventricular ejection fraction of 34% ± 16%. Seventeen (45%) patients had previous cardiac surgery (coronary bypass and/or valve replacement). The transvenous lead system included the Endotak C (single) lead of CPI ( n = 27) or the EnGuard double-lead system of Telectronics ( n = 11). The integrated pace/sense/defibrillation lead(s) were usually introduced via the left cephalic vein; after endocardiac positioning and testing, the leads were tunneled to the abdominal pocket in which the ICD device was implanted. DFTs were adequate for all patients (100%) and averaged 13.5 ± 5.4 J (range 2.4 to 25 J). A subcutaneous patch or array was needed in only three patients. Because of protocol requirements, a subcutaneous patch or electrode array was intraoperatively tested in another three patients but was finally not implanted because better DFTs were achieved with the transvenous lead-alone configuration. The leads were combined with second-generation devices in 12 patients and third-generation ICDs in 26 (68%) patients. Lead dislodgement required revision in 2 patients; 1 patient had ipsilateral venous thrombosis successfully treated with anticoagulation. At predischarge testing, all devices functioned well. We conclude that with the newer generation transvenous lead ICD systems there is rarely need for a subcutaneous patch, making possible pure transvenous ICD implants in the majority (92%) of patients.