Fluoroscopic screening of asymptomatic patients implanted with the recalled Riata lead family.

BACKGROUND: The Food and Drug Administration recently issued a class I recall of the St. Jude Medical Riata implantable cardioverter-defibrillator lead presumably because of increased risk of electric failure and mechanical separation via inside-out abrasion. We sought to examine the incidence and time dependence of inside-out abrasion in asymptomatic patients implanted with the Riata lead. METHODS AND RESULTS: Asymptomatic patients implanted with the Riata lead at our institution were offered voluntary fluoroscopic screening in 3 views. Electric testing of the Riata lead with provocative isometric muscle contraction was performed at the time of fluoroscopic screening. Of the 245 patients undergoing fluoroscopic screening, 53 (21.6%) patients showed clear evidence of lead separation. Of these externalized leads, 0%, 13%, and 26% had a dwell time of <3 years, 3 to 5 years, and >5 years, respectively (P=0.037). Externalized leads had a significantly pronounced decrease in R-wave amplitude (-1.7±2.9 mV versus +0.35±2.5 mV; P<0.001), and more patients with externalized leads had ≥25% decrease in R-wave amplitude from baseline (28.0% versus 8.1%; P=0.018). One patient with externalization exhibited new noise on near-field electrogram. CONCLUSIONS: The Riata lead exhibits time-dependent high rates of cable externalization exceeding 20% at >5 years of dwell time. Externalized leads are associated with a more pronounced decrease in R-wave amplitude, which may be an early marker of future electric failure. The use of fluoroscopic and electric screening of asymptomatic patients with the Riata lead remains controversial in the management of patients affected by the recent Food and Drug Administration recall.

Catheter ablation to suppress atrial fibrillation: evolution of technique at a single center.

BACKGROUND: Catheter ablation of atrial fibrillation is a rapidly evolving art. There is currently no consensus as to optimal methodology. We report a sequential experience, during which three distinct ablation techniques were utilized. METHODS: A cohort of 112 patients in whom atrial fibrillation onset was precipitated by ectopy arising solely from myocardium investing the pulmonary veins underwent catheter ablation using one of three techniques: focal (Group A); individual vein encircling (Group B); vestibule encircling (Group C). In each group, non-fluoroscopic guidance of the mapping and ablation process was provided by the tandem use of CARTO and intracardiac echocardiography. RESULTS: In all groups, endocardial topography was complex, and ablation electrode-endocardial contact was often unstable. Maximal electrode temperatures were low, despite frequent echocardiographic evidence of myocardial boiling. A significant progression in the number of radiofrequency energy applications between groups A and C was observed. Although acute suppression of atrial fibrillation inducibility was observed uniformly, chronic suppression rates were significantly different: Group A = 47%; Group B; 69%; Group C = 87%. CONCLUSIONS: In this non-concurrent cohort, the rate of chronic suppression of atrial fibrillation correlated with the amount of myocardium ablated or electrically isolated. Prospective data will be required to further evaluate whether "more is better."