Repeat ablation of refractory ventricular arrhythmias in patients with nonischemic cardiomyopathy: Impact of midmyocardial substrate and role of adjunctive ablation techniques.

INTRODUCTION: Multiple ablations are often necessary to manage ventricular arrhythmias (VAs) in nonischemic cardiomyopathy (NICM) patients. We assessed characteristics and outcomes and role of adjunctive, nonstandard ablation in repeat VA ablation (RAbl) in NICM. METHODS AND RESULTS: Consecutive NICM patients undergoing RAbl were analyzed, with characteristics of the last VA ablations compared between those undergoing 1 versus multiple-repeat ablations (1-RAbl vs. >1RAbl), and between those with or without midmyocardial substrate (MMS). VA-free survival was compared. Eighty-eight patients underwent 124 RAbl, 26 with > 1RAbl, and 26 with MMS. 1-RAbl and > 1-RAbl groups were similar in age (57 ± 16 vs. 57 ± 17 years; P = 0.92), males (76% vs. 69%; P = 0.60), LVEF (40 ± 17% vs. 40 ± 18%; P = 0.96), and amiodarone use (31% vs. 46%, P = 0.22). One-year VA freedom between 1-RAbl vs. > 1RAbl was similar (82% vs. 80%; P = 0.81); adjunctive ablation was utilized more in >1RAbl (31% vs. 11%, P = 0.02), and complication rates were higher (27% vs. 7%, P = 0.01), most due to septal substrate and anticipated heart block. >1-RAbl patients had more MMS (62% vs. 16%, P < 0.01). Although MMS was associated with worse VA-free survival after 1-RAbl (43% vs. 69%, P = 0.01), when >1RAbl was performed, more often with nonstandard ablation, VA-free survival was comparable to non-MMS patients (85% vs. 81%; P = 0.69). More RAbls were required in MMS versus non-MMS patients (2.00 ± 0.98 vs. 1.16 ± 0.37; P < 0.001). CONCLUSION: For NICM patients with recurrent, refractory VAs despite previous ablation, effective arrhythmia control can safely be achieved with subsequent ablation, although >1 repeat procedure with adjunctive ablation is often required, especially with MMS.

Preoperative assessment for children requiring dental treatment under general anesthesia.

OBJECTIVE: This study aimed to describe children <6 years requiring general anesthesia for dental treatment and factors associated with a change in medical management prior to surgery. STUDY DESIGN: This case series reviewed the past medical history and preoperative assessment of patients referred for dental preoperative evaluations at a single institution (2005-2008). A "deflection" was defined as a recommendation to change preoperative or operative care based on the preoperative assessment. The sample was analyzed using descriptive, bivariate, and multivariate analyses. RESULTS: Of 648 subjects (aged 9 months to 6 years, mean 3.9 years), 63% had a past medical history abnormality and 38% had previous surgery. In total, 14% were deflected, most commonly because of the addition of infective endocarditis prophylaxis (29%). A history of coagulation disorder had the strongest association with deflection (P < .0001, odds ratio = 10.0, 95% confidence interval = 4.6-22.1), followed by cardiac anomalies. CONCLUSION: Preoperative assessments for pediatric dental treatment frequently identify medical problems resulting in treatment plan alterations.