Claude S. Elayi

Esophageal Capsule Endoscopy After Radiofrequency Catheter Ablation for Atrial Fibrillation Documented Higher Risk of Luminal Esophageal Damage With General Anesthesia as Compared With Conscious Sedation

Background—Left atrioesophageal fistula is a rare but devastating complication that may occur after catheter ablation of atrial fibrillation. We used capsule endoscopy to assess esophageal injury after catheter ablation for atrial fibrillation in a population randomized to undergo general anesthesia or conscious sedation. Methods and Results—Fifty patients undergoing atrial fibrillation ablation for paroxysmal symptomatic atrial fibrillation refractory to antiarrhythmic drugs were enrolled and randomized, including those undergoing the procedure under general anesthesia (25 patients, group 1) and those receiving conscious sedation with fentanyl or midazolam (25 patients, group 2). All patients underwent esophageal temperature monitoring during the procedure. The day after ablation, all patients had capsule endoscopy to assess the presence of endoluminal tissue damage of the esophagus. We observed esophageal tissue damage in 12 (48%) patients of group 1 and 1 esophageal tissue damage in a single patient (4%) of group 2 (P<0.001). The maximal esophageal temperature was significantly higher in patients undergoing general anesthesia (group 1) versus patients undergoing conscious sedation (group 2) (40.6±1°C versus 39.6±0.8°C; P< 0.003). The time to peak temperature was 9±7 seconds in group 1 and 21±9 seconds in group 2, and this difference was statistically significant (P<0.001). No complication occurred during or after the administration of the pill cam or during the procedures. All esophageal lesions normalized at the 2-month repeat endoscopic examination. Conclusion—The use of general anesthesia increases the risk of esophageal damage detected by capsule endoscopy.

Integration of positron emission tomography/computed tomography with electroanatomical mapping: A novel approach for ablation of scar-related ventricular tachycardia

BACKGROUNDnDespite the recent advances in cardiac mapping, ablation of scar-related ventricular tachycardia (VT) still remains a clinical challenge. A detailed electroanatomical map is a prerequisite for accurate localization and ablation of the VT substrate.nnnOBJECTIVEnThe purpose of this study was to evaluate the feasibility and accuracy of integrating the positron emission tomography (PET)/computed tomography (CT) with the electroanatomical map and compare the accuracy of the voltage-based scar with the biological scar.nnnMETHODSnPatients undergoing radiofrequency ablation (n = 19) for scar-related VT were enrolled. CT angiography and PET scans were performed for all patients. Tomographic and volumetric data from both images were processed and coregistered using internally designed software. That image was segmented in an electrophysiology mapping system and registered to the electroanatomical map. Eight different thresholds were applied on the voltage map to define the scar. The surface areas of the biological and electrical dense scars at different thresholds were measured and compared.nnnRESULTSnThe PET/CT image was well integrated with the electroanatomical map with a mean surface registration error of 5.1 +/- 2.1 mm. Of the eight different thresholds defining the scar, the surface area of the scar at a threshold of 0.9 mV (68.6 +/- 49.2 cm(2)) correlated best with the surface area of the PET-based scar (70.4 +/- 49.3 cm(2)) and had the least total area error (4.8 +/- 1.8 cm(2)) compared with the 0.5 threshold (29.7 +/- 23.9 cm(2)).nnnCONCLUSIONnIntegrating PET/CT with the electroanatomical map is feasible and accurate. Based on the biological scar, readjustment of the voltage scar threshold to 0.9 mV is suggested. In view of the better accuracy of PET/CT in defining scar, the need for acquiring detailed voltage maps may be obviated.

Transiliac ICD implantation: Defibrillation vector flexibility produces consistent success

BACKGROUNDnThe transiliac approach to implantable cardioverter-defibrillator (ICD) implantation is an alternative in patients for whom pectoral placements are contraindicated. The defibrillation vector is altered from the pectoral configuration because of pulse generator placement in one of the upper abdominal quadrants and separate single-coil, active-fixation defibrillation leads positioned in the high right atrium and right ventricular apex.nnnOBJECTIVEnThe feasibility, safety, and complications of this approach and the results of defibrillation testing (DFT) with this configuration are described.nnnMETHODSnTwenty-three patients (16 male and 7 female, mean age 65.7 +/- 13.2 years) required transiliac approach to ICD placement. The leads were inserted through the iliac vein immediately superior to the inguinal ligament. When required, a subcutaneous coil was tunneled posterior to the left ventricle from the left axilla.nnnRESULTSnThe right iliac vein entry was used in 17 patients, with placement of the pulse generator in the left upper quadrant in 16 patients. Atrial and ventricular lead pacing and sensing function were acceptable. Initial defibrillation success with a safety margin of 10 J was achieved in 15 patients. With the placement of an additional subcutaneous coil in the remaining 8 patients, defibrillation success with a safety margin of 10 J was increased to 19 patients, whereas defibrillation success with a safety margin of 5 J was achieved in all patients, although 1 patient required repeat testing 24 hours after implantation. There were no acute complications. Late complications occurred in 3 patients, comprised of atrial lead malfunction, device infection, and right ventricular defibrillation lead fracture.nnnCONCLUSIONnThe iliac vein approach to ICD implantation is a safe and effective alternative technique. Flexibility in lead placement, defibrillation vectors, and careful DFT are required to produce a consistently effective system.

Is there an association between external cardioversions and long-term mortality and morbidity? Insights from the Atrial Fibrillation Follow-up Investigation of Rhythm Management study.

Background— Cardiac electric therapies effectively terminate tachyarrhythmias. Recent data suggest a possible increase in long-term mortality associated with implantable cardioverter-defibrillator shocks. Little is known about the association between external cardioversion episodes (ECVe) and long-term mortality. We sought to assess the safety of repeated ECVe with regard to cardiovascular mortality and morbidity. Methods and Results— We analyzed the data of the 4060 patients from the AFFIRM (Atrial Fibrillation Follow-up Investigation of Rhythm Management) trial. In particular, associations of ECVe with all-cause mortality, cardiovascular mortality, and hospitalizations after ECVe were studied. Over an average follow-up of 3.5 years, 660 (16.3%) patients died, 331 (8.2%) from cardiovascular causes. A total of 207 (5.1%) and 1697 (41.8%) patients had low ejection fraction and nonparoxysmal atrial fibrillation, respectively; 2460 patients received no ECVe, whereas 1600 experienced ≥1 ECVe. Death occurred in 412 (16.7%), 196 (16.5%), 39 (13.5%), and 13 (10.4%) of patients with 0, 1, 2, and ≥3 ECVe, respectively. There was no significant association between ECVe and mortality within any of the 4 subgroups defined by ejection fraction and atrial fibrillation type, although myocardial infarction, coronary artery bypass graft, and digoxin were significantly associated with death (estimated hazard ratios, 1.65, 1.59, and 1.62, respectively; P<0.0001). ECVe were associated with increased cardiac hospitalization reported at the next follow-up visit (39.3% versus 5.8%; estimated odds ratio, 1.39; P<0.0001). Conclusions— In the AFFIRM study, there was no significant association between ECVe and long-term mortality, even though ECVe were associated with increased hospitalizations from cardiac causes. Digoxin, myocardial infarction, and coronary artery bypass graft were significantly associated with mortality.Background —Cardiac electrical therapies effectively terminate tachyarrhythmias. Recent data suggest a possible increase in long-term mortality associated with implantable cardiac defibrillator shocks. Little is known about the association between external cardioversion episodes (ECVe) and long-term mortality. We sought to assess the safety of repeated ECVe with regards to cardiovascular mortality and morbidity.nn Methods and Results —We analyzed the data of the 4,060 patients from the AFFIRM trial. In particular, associations of ECVe with all-cause mortality, cardiovascular mortality and hospitalizations post ECVe were studied.nOver an average follow-up of 3.5 years, 660 patients (16.3%) died, 331(8.2%) from cardiovascular causes. A total of 207(5.1%) and 1697(41.8%) patients had low ejection fraction (EF) and non-paroxysmal atrial fibrillation (AF) respectively. 2460 patients received no ECVe; while 1600 experienced ≥1 ECVe. Death occurred in 412(16.7%), 196(16.5%), 39(13.5%), and 13(10.4%) of patients with 0, 1, 2, and ≥3 ECVe respectively. There was no significant association between ECVe and mortality within any of the four subgroups defined by EF and AF type, although myocardial infarction (MI), coronary artery bypass graft (CABG), and digoxin were significantly associated with death (Estimated hazard ratios: 1.65; 1.59 and 1.62 respectively, p<0.0001). ECVe were associated with increased cardiac hospitalization reported at the next follow-up visit (39.3% vs. 5.8%; Estimated odds ratio: 1.39, p<0.0001).nn Conclusions —In the AFFIRM study, there was no significant association between ECVe and long-term mortality, even though ECVe were associated with increased hospitalizations from cardiac causes. Digoxin, MI, and CABG were significantly associated with mortality.

Pulmonary vein calcification by EBCT in patients with drug refractory nonvalular atrial fibrillation

IntroductionPulmonary veins in patients with atrial fibrillation (AF) have been shown to be highly arrhythmogenic. Calcification in these veins may play an adjunctive role in the pathogenesis of AF.Methods and ResultsA case control study was performed in patients with drug refractory nonvalvular AF whose preablation computed tomography chest scans demonstrated pulmonary vein (PV) calcification. Eight out of 48 patients with PV calcification were compared to 50 patients without AF who underwent electron beam computed tomography coronary artery calcium scores. These patients were matched for age, gender, coronary artery calcium scores, and the presence of PV calcification. The mean age of the combined group was 57u2009±u20099xa0years and 60% were men. The mean total PV calcium score was significantly higher at 199u2009±u2009112 in patients with AF compared to 106u2009±u200952 in controls (pu2009=u20090.018). Men had significantly higher total PV calcium score than women in both groups.ConclusionTotal PV calcium score was significantly higher in patients with atrial fibrillation. Increased PV calcification may play an adjunctive role in the pathogenesis in initiating and maintaining AF.

The Effects of Catheter Ablation on Permanent Pacemakers and Implantable Cardiac Defibrillators

Catheter ablation is a procedure that is frequently performed in patients with cardiac implantable electronic devices. Here, we review all of the potential interactions that can occur among patients undergoing catheter ablation while having implantable cardiac electronic devices, and discuss the precautionary measures to minimize such interactions.