A comparison of right ventricular non-apical defibrillator lead position with traditional right ventricular apical position: a single centre experience.

BACKGROUND: Implantable cardioverter defibrillator (ICD) leads have traditionally been placed at the right ventricular apex (RVA). An important minority of patients with an ICD may develop a future requirement for bradycardia support. Pacing from the RVA may be detrimental, promoting heart failure and mortality. Increasingly non-apical right ventricular (RVNA) lead positions have been suggested as an alternative pacing site. METHODS: A retrospective review of 512 patients who received an ICD at our institution between 1999 and 2011 was conducted. A comparison of lead performance characteristics was performed between RVNA sites and those at RVA. Data were collated from chart review and the pacing database. RESULTS: The mean follow-up period in the RVNA cohort was 40.4±25.9 months and in the RVA cohort it was 38±31.8 months (p=0.43). The RVNA cohort consisted of 144 leads and 368 leads in the RVA cohort. The groups had similar baseline clinical characteristics. No significant difference was detected in the proportion of patients receiving an appropriate ICD defibrillation (RVNA 10.4% vs. RVA 16.8%; p=0.07), inappropriate defibrillation (RVNA 7.6% vs. RVA 7.6%; p=0.99) or an unsuccessful defibrillation (RVNA 0% vs. RVA 1.7%; p=0.12). There was also no significant difference in the proportion of patients receiving successful anti-tachycardia pacing (ATP) (RVNA 13.2% vs. RVA 17.4%; p=0.49) or failed ATP (RVNA 2.7% vs. RVA 4.1%; p=0.25). There was no significant difference in lead impedance (p=0.99), sensing (p=0.59) and pacing threshold (p=0.34). CONCLUSION: In this large retrospective study, RVNA ICD lead had similar stability and therapy efficacy compared to the traditional RVA position. This potentially has important implications for the suitability of RVNA as an alternative site for ICD leads.