Sheldon M. Singh

Esophageal Injury and Temperature Monitoring During Atrial Fibrillation Ablation

Background— It is common practice to empirically limit the radiofrequency (RF) power when ablating the posterior left atrium during atrial fibrillation ablation to avoid thermal injury to the esophagus. The objective of this study was to determine whether RF energy delivery limited by luminal esophageal temperature (LET) monitoring is associated with a reduction in esophageal injury compared with a strategy of RF power limitation alone. Methods and Results— Eighty-one consecutive patients who underwent atrial fibrillation ablation followed by esophageal endoscopy were included in this observational study. All patients underwent extraostial electric pulmonary vein isolation by using an electroanatomic mapping system and irrigated RF ablation. All RF applications on the posterior left atrium were limited to 35 W. A commercially available, single-thermocouple esophageal probe was used to monitor LET in a subset of patients (n=67). In these cases, applications were promptly interrupted when LET was ≥38.5°C; further applications were performed at reduced power to obtain a LET <38.5°C. Esophageal endoscopy was performed 1 to 3 days after the procedure. Ablation-related esophageal ulcerations were identified in 9 of 81 (11%) patients. All patients were asymptomatic. Of these 81 patients, LET monitoring during ablation occurred in 67 (83%) of patients. Esophageal injury was observed more frequently (36% versus 6%, P<0.006) in the group without LET monitoring. Conclusions— These data suggest that LET monitoring may be associated with a reduction in esophageal injury compared with power limitation alone.

Esophageal Injury and Temperature Monitoring During Atrial Fibrillation AblationCLINICAL PERSPECTIVE

Background— It is common practice to empirically limit the radiofrequency (RF) power when ablating the posterior left atrium during atrial fibrillation ablation to avoid thermal injury to the esophagus. The objective of this study was to determine whether RF energy delivery limited by luminal esophageal temperature (LET) monitoring is associated with a reduction in esophageal injury compared with a strategy of RF power limitation alone. Methods and Results— Eighty-one consecutive patients who underwent atrial fibrillation ablation followed by esophageal endoscopy were included in this observational study. All patients underwent extraostial electric pulmonary vein isolation by using an electroanatomic mapping system and irrigated RF ablation. All RF applications on the posterior left atrium were limited to 35 W. A commercially available, single-thermocouple esophageal probe was used to monitor LET in a subset of patients (n=67). In these cases, applications were promptly interrupted when LET was ≥38.5°C; further applications were performed at reduced power to obtain a LET <38.5°C. Esophageal endoscopy was performed 1 to 3 days after the procedure. Ablation-related esophageal ulcerations were identified in 9 of 81 (11%) patients. All patients were asymptomatic. Of these 81 patients, LET monitoring during ablation occurred in 67 (83%) of patients. Esophageal injury was observed more frequently (36% versus 6%, P <0.006) in the group without LET monitoring. Conclusions— These data suggest that LET monitoring may be associated with a reduction in esophageal injury compared with power limitation alone. Received March 20, 2008; accepted May 30, 2008.

Association of socioeconomic status and receipt of colorectal cancer investigations: a population-based retrospective cohort study

Background: Although the Canadian health care system was designed to ensure equal access, inequities persist. It is not known if inequities exist for receipt of investigations used to screen for colorectal cancer (CRC). We examined the association between socioeconomic status and receipt of colorectal investigation in Ontario. Methods: People aged 50 to 70 years living in Ontario on Jan. 1, 1997, who did not have a history of CRC, inflammatory bowel disease or colorectal investigation within the previous 5 years were followed until death or Dec. 31, 2001. Receipt of any colorectal investigation between 1997 and 2001 inclusive was determined by means of linked administrative databases. Income was imputed as the mean household income of the persons census enumeration area. Multivariate analysis was performed to evaluate the relationship between the receipt of any colorectal investigation and income. Results: Of the study cohort of 1 664 188 people, 21.2% received a colorectal investigation in 1997–2001. Multivariate analysis demonstrated a significant association between receipt of any colorectal investigation and income (p < 0.001); people in the highest-income quintile had higher odds of receiving any colorectal investigation (adjusted odds ratio [OR] 1.38; 95% confidence interval [CI] 1.36–1.40) and of receiving colonoscopy (adjusted OR 1.50; 95% CI 1.48–1.53). Interpretation: Socioeconomic status is associated with receipt of colorectal investigations in Ontario. Only one-fifth of people in the screening-eligible age group received any colorectal investigation. Further work is needed to determine the reason for this low rate and to explore whether it affects CRC mortality.

Economic Evaluation of Percutaneous Left Atrial Appendage Occlusion, Dabigatran, and Warfarin for Stroke Prevention in Patients With Nonvalvular Atrial Fibrillation

Background— Percutaneous left atrial appendage (LAA) occlusion and novel pharmacological therapies are now available to manage stroke risk in patients with nonvalvular atrial fibrillation; however, the cost-effectiveness of LAA occlusion compared with dabigatran and warfarin in patients with nonvalvular atrial fibrillation is unknown. Methods and Results— Cost-utility analysis using a patient-level Markov microsimulation decision analytic model with a lifetime horizon was undertaken to determine the lifetime costs, quality-adjusted life years, and incremental cost-effectiveness ratio of LAA occlusion in relation to dabigatran and warfarin in patients with nonvalvular atrial fibrillation at risk for stroke without contraindications to oral anticoagulation. The analysis was performed from the perspective of the Ontario Ministry of Health and Long Term Care, the third-party payer for insured health services in Ontario, Canada. Effectiveness and utility data were obtained from the published literature. Cost data were obtained from the Ontario Drug Benefits Formulary and the Ontario Case Costing Initiative. Warfarin therapy had the lowest discounted quality-adjusted life years at 4.55, followed by dabigatran at 4.64 and LAA occlusion at 4.68. The average discounted lifetime cost was

Acute and Long‐Term Outcomes of Catheter Ablation of Atrial Fibrillation Using the Second‐Generation Cryoballoon versus Open‐Irrigated Radiofrequency: A Multicenter Experience

21 429 for a patient taking warfarin,

Image integration using intracardiac ultrasound to guide catheter ablation of atrial fibrillation

25 760 for a patient taking dabigatran, and

Clinical outcomes after repair of left atrial esophageal fistulas occurring after atrial fibrillation ablation procedures

27 003 for LAA occlusion. Compared with warfarin, the incremental cost-effectiveness ratio for LAA occlusion was

The Incidence and Long-Term Clinical Outcome of Iatrogenic Atrial Septal Defects Secondary to Transseptal Catheterization With a 12F Transseptal Sheath

41 565. Dabigatran was extendedly dominated. Conclusions— Percutaneous LAA occlusion represents a novel therapy for stroke reduction that is cost-effective compared with warfarin for patients at risk who have nonvalvular atrial fibrillation.

Cutaneous nocardiosis complicating management of Crohn's disease with infliximab and prednisone

There are limited comparative data on catheter ablation of atrial fibrillation (CAAF) using the second‐generation cryoballoon (CB‐2) versus point‐by‐point radiofrequency (RF). This study examines the acute/long‐term CAAF outcomes using these 2 strategies.

Luminal Esophageal Temperature Monitoring With a Deflectable Esophageal Temperature Probe and Intracardiac Echocardiography May Reduce Esophageal Injury During Atrial Fibrillation Ablation Procedures Results of a Pilot Study

BACKGROUND Three-dimensional (3D) reconstruction of the left atrium (LA) can be performed using real-time intracardiac echocardiography (ICE) to facilitate image integration during atrial fibrillation (AF) ablation. Current users of this technology generally image the LA indirectly from the right atrium (RA). OBJECTIVE The purpose of this study was to assess the feasibility and accuracy of image integration with placement of the ICE catheter directly in the LA to visualize the LA. METHODS Thirty consecutive patients undergoing an AF ablation with the CARTO-Sound system were enrolled. A 10-Fr phased-array ICE catheter was used to obtain two-dimensional echocardiographic images of the LA; in 15 patients the ICE probe was placed in the LA, and in 15 patients it was placed only in the RA. Sequential images were obtained and merged with a preacquired computed tomography/magnetic resonance image. The accuracy of image integration was assessed by the value of the average image integration error after surface registration. RESULTS Thirty patients (60% paroxysmal AF, LA size = 42 +/- 7 mm, ejection fraction = 62% +/- 10%) were studied. There was no difference in the time required to create the LA anatomic map and perform image integration with imaging from the LA versus the RA (22 +/- 22 vs. 24 +/- 16 minutes; P = .8). The number of ultrasound contours obtained was also similar (LA = 26 +/- 17 vs. RA = 24 +/- 16; P = .7). The average integration error was less with direct LA imaging (LA = 1.83 +/- 0.32 vs. RA = 2.52 +/- 0.58 mm; P = .0004). CONCLUSION Direct LA imaging with ICE is feasible and results in improved LA visualization and image integration.