Percutaneous Access of the Epicardial Space for Mapping Ventricular and Supraventricular Arrhythmias in Patients With and Without Prior Cardiac Surgery

Percutaneous Epicardial Access . Introduction: There is a paucity of data on the success rates of achieving percutaneous epicardial access in different groups of patients. Methods and Results: Percutaneous epicardial access was attempted in 137 patients having 149 procedures; 19 patients had supraventricular tachycardia (SVT), 25 patients had idiopathic VT and 93 patients had scar‐related ventricular tachycardia (VT). Ten patients had prior cardiac surgery. Successful epicardial access was achieved in 133 of 149 (89.3%) procedures. Access was achieved in 17 of 19 (89.5%) patients with SVT, all patients with idiopathic VT, 80 of 93 (86.0%) patients with scar‐related VT and in 2 (20%) patients with prior cardiac surgery. Attempted access failed in 16 patients; 8 had prior cardiac surgery and 3 had prior pericarditis. After an initial procedure, repeat access was attempted in 15 patients, 5.1 ± 5.4 months after initial epicardial mapping and ablation. Access was successful in 13 (86.7%) and failed in 2 patients who had pericarditis after their first procedure. Only 4 patients were given intrapericardial glucocorticoid at their first epicardial procedure. Prior cardiac surgery and a history of pericarditis predicted unsuccessful access (P < 0.01). Complications (9 patients) included pericardial bleeding (80–250 mL) and intraabdominal bleeding. Conclusions: In patients without prior cardiac surgery, percutaneous epicardial access can be obtained in the majority of patients. Prior cardiac surgery precludes access in the most patients and when possible adhesions may limit catheter movement. Repeat access is possible in the majority of patients without the installation of intrapericardial glucocorticoid at the first procedure. (J Cardiovasc Electrophysiol, Vol. 21, pp. 406–411, April 2010)     

Our Approach to Minimize Risk of Epicardial Access: Standard Techniques with the Addition of Electroanatomic Mapping Guidance

Epicardial mapping and ablation is increasingly being performed for the treatment of complex arrhythmias. Right ventricular (RV) puncture remains the most common complication, with damage to surrounding non‐cardiac structures also a concern. We describe the standard techniques used in our lab essential for safe epicardial access, as well as a novel technique incorporating electroanatomic mapping (EAM) guidance. In a series of 8 patients referred for ventricular tachycardia ablation, an RV endocardial voltage map was created using EAM systems. EAM images were fused with preprocedure CT scans when available. A 17G Tuohy needle was integrated with the EAM system by attaching the needle to sterile electrode clamps. EAM location points were used in conjunction with standard access techniques until epicardial access was obtained. Epicardial access was successfully obtained in 8/8 (100%) patients. Successful access without RV puncture was achieved in 7/8 (88%) cases. This proof of concept study demonstrates that EAM systems can be used as an adjunct to standard access techniques to visualize and facilitate pericardial access.     

Epicardial adipose tissue is a robust measure of increased risk of myocardial infarction – a meta-analysis on over 6600 patients and rationale for the EPIC-ACS study

Background:Epicardial adipose tissue (EAT) surrounds the heart and the coronary vessels. EAT produces pro- and anti-inflammatory cytokines. Several studies have already documented the association of EAT and cardiovascular risk factors as well as coronary artery disease manifestations. Currently computed tomography (CT) is considered the gold standard for measurement of 3-dimensional volume of EAT. In addition, echocardiography might be an easy accessible alternative in particular in an emergency setting.Methods:We performed a metaanalysis of existing studies describing the differences of EAT in patients with and without myocardial infarction. We used established databases and were searching for “epicardial adipose tissue” or “pericardial adipose tissue” and “myocardial infarction”, “coronary events”, or “acute coronary syndrome”. We included over 6600 patients from 7 studies. Random effect models were calculated and all analyses were performed by using the Review Manager 5.3.Results:Patients with myocardial infarction had 37% (confidence interval [0.21-0.54], P value <.001)] higher measures of EAT compared to patients without myocardial infarction. Comparing studies using echocardiography vs CT for assessment of EAT thickness, similar relative differences in EAT with wide overlap of confidence intervals were observed (for echocardiography: 0.4 [0.04-0.76], for CT: 0.36 [0.16-0.57], P value <.001 for both).Conclusions:Patients with myocardial infarction have more EAT as compared to patients without myocardial infarction independently of the used imaging modality. Further prospective studies are needed to evaluate, how quantification of EAT in clinical routine can improve patients management.     

Regional Pericarditis: A Review of the Pericardial Manifestations of Acute Myocardial Infarction

Regional pericarditis has been described in several settings, but occurs most frequently after transmural myocardial infarction. While the diagnosis remains elusive, it must be considered in all patients with recurrent chest pain following acute myocardial infarction (AMI). Pericarditis classically presents with positional chest pain, a pericardial friction rub, diffuse ST‐segment elevation, and PR depression, but regional ECG changes associated with infarction‐associated pericarditis sometimes exist. Given the magnitude and frequency of AMI, it is imperative to be aware of the myriad of pericardial manifestations of myocardial injury. An illustrative case and a comprehensive review of the literature will be provided. Copyright © 2009 Wiley Periodicals, Inc.     

A rare complication of a rare disease: Pericarditis due to ruptured pericardial cyst

Pericardial cysts are considered rare incidental findings, which are generally asymptomatic in nature. Occasionally, patients may represent with chest discomfort, dyspnea, or palpitations. Pericarditis related to a ruptured pericardial cyst has not been previously reported in the literature. Here, we report the case of a 62-year-old man who developed acute pericarditis as a result of a ruptured enlarging pericardial cyst.     

Three‐Dimensional CT Overlay in Comparison to CartoMerge for Pulmonary Vein Antrum Isolation

CT Overlay for PV Antrum Isolation . Introduction: Three‐dimensional (3D) navigation systems are widely used for pulmonary vein antrum isolation (PVAI). To circumvent left atrial (LA) mapping, 3D CT reconstructions of the LA can be superimposed directly (CT overlay) on the fluoroscopy image to guide ablation catheters and to mark ablation sites. Methods and Results: Sixty‐eight patients (pts) with symptomatic AF refractory to medical therapy were randomly assigned to CT overlay (group 1, n = 38) or CartoMerge (group 2, n = 30). In group 1 registration of the CT image was performed with contrast injections in 2 orthogonal projections. In group 2, visualization of all pulmonary vein (PV) ostia was done by PV angiography, followed by merging of the CT image and the Carto shell. We compared procedural success, procedure time, fluoroscopy time and radiation burden, measured as dose area product (DAP). Baseline characteristics were comparable in both groups. Procedural success, defined as disappearance of PV potentials in all PVs, was achieved in 37/38 (97%) of group 1 patients and 27/30 (90%) patients in group 2 (P = NS). Total procedure time was significantly shorter in group 1 compared to group 2 (129 ± 34 vs 181 ± 30 min, P < 0.0001). Although fluoroscopy time tended to be longer in the CT overlay group (47 ± 16 vs 40 ± 13 min, P = 0.06), proper use of diaphragmation resulted in comparable radiation values for both groups (DAP 53 ± 27 vs 56 ± 35 Gy cm², P = 0.76). Conclusions: CT overlay for PV isolation is feasible and may, in comparison to conventional LA navigation systems, shorten procedural time without increases in radiation burden. (J Cardiovasc Electrophysiol, Vol. 21, pp. 634‐639, June 2010)     

Validation of computed tomography image integration into the EnSite NavX mapping system to perform catheter ablation of atrial fibrillation

Introduction: The complex anatomy of the left atrium (LA) makes location of ablation catheters difficult using fluoroscopy alone, and therefore 3D mapping systems are now routinely used. We describe the integration of a CT image into the EnSite NavX System with Fusion and its validation in patients undergoing atrial fibrillation (AF) or left atrial tachycardia (AT) catheter ablation. Methods and Results: Twenty‐three patients (61 ± 9.2 years, 16 male) with paroxysmal (14) and persistent (8) AF and persistent (1) AT underwent ablation using CT image integration into the EnSite NavX mapping system with the EnSite Fusion Dynamic Registration software module. In all cases, segmentation of the CT data was accomplished using the EnSite Verismo segmentation tool, although repeat segmentation attempts were required in seven cases. The CT was registered with the NavX‐created geometry using an average of 24 user‐defined fiducial pairs (range 9 to 48). The average distance from NavX‐measured lesion positions to the CT surface was 3.2 ± 0.9 mm (median 2.4 mm). A large, automated, retrospective test using registrations with random subsets of each patient's fiducial pairs showed this average distance decreasing as the number of fiducial pairs increased, although the improvement ceased to be significant beyond 15 pairs. In confirmation, those studies which had used 16 or more pairs had a smaller average lesion‐to‐surface distance (2.9 ± 0.7 mm) than those using 15 or fewer (4.3 ± 0.8 mm, P < 0.02). Finally, for the 13 patients who underwent left atrial circumferential ablation (LACA), there was no significant difference between the circumference computed using NavX‐measured positions and CT surface positions for either the left pulmonary veins (178 ± 64 vs. 177 ± 60 mm; P = 0.81) or the right pulmonary veins (218 ± 86 vs. 207 ± 81 mm; P = 0.08). Conclusion: CT image integration into the EnSite NavX Fusion system was successful in all patients undergoing catheter ablation. A learning curve exists for the Verismo segmentation tool; but once the 3D model was created, the registration process was easily accomplished, with a registration error that is comparable with registration errors using other mapping systems with CT image integration. All patients went on to have subsequent successful ablation procedures. Where LACA was performed (13 patients), only four patients required segmental ostial lesions to achieve electrical isolation.     

Relationship of the esophagus and aorta to the left atrium and pulmonary veins: Implications for catheter ablation of atrial fibrillation

BACKGROUND: A potential complication during ablation of atrial fibrillation (AF) is damage to adjacent structures such as the esophagus and aorta. Fatal atrio-esophageal fistulas have developed after surgery- or catheter-based AF ablation procedures. OBJECTIVES: The purpose of this study was to analyze multidetector computed tomography (MDCT) angiographic images to determine the anatomic relationship of the aorta and esophagus to the left atrium (LA). METHODS: Sixty-five subjects underwent CT imaging using a 16-slice MDCT scanner: 24 with paroxysmal AF, 21 with chronic AF, and 20 "control" subjects without a history of AF. Measurements assessed included LA diameters, width of the esophagus and aorta in contact with the posterior LA wall, and distance from the esophagus to the four pulmonary veins (PVs), spine, and LA endocardium. RESULTS: Mean LA diameters were significantly larger in patients with AF vs the control group (P = .003 for anteroposterior diameter; P = .009 for transverse diameter). The anterior aspect of the esophagus was directly apposed to the LA in all cases (contact width 18.9 +/- 4.4 mm). The position of the esophagus varied in the posterior mediastinum but on average was closer to the ostia of the left PVs (P = .0001). The descending aorta was in contact with the LA and/or left PVs in 50 of 65 subjects. The esophagus was closer to the spine in the chronic AF vs control group (P = .007), likely due to increased LA dimension. CONCLUSION: In addition to its ability to assess PV anatomy, preprocedural MDCT imaging can investigate the variable relationship of adjacent structures, such as the esophagus and aorta to the LA and PVs.     

VIRTUAL ENTEROSCOPY USING AIR AS THE CONTRAST MATERIAL: A PRELIMINARY FEASIBILITY STUDY

Background: There are no studies to date using air as an enteral contrast medium for small bowel expansion in virtual enteroscopy. We examine the feasibility of air as an enteral contrast medium for virtual enteroscopy to achieve small bowel expansion. Patients and Methods: Two volunteers and six patients were examined. The six patients included three with small bowel tumors, one with small bowel hemorrhage and two with suspected cases of post‐operative small bowel stenosis. A duodenal tube was inserted under fluoroscopy and approximately 2000 ml air was administered prior to scanning. A 16‐detector row computed tomography apparatus was used with 2‐mm thick slices. Intravenous contrast material was administered to the patients, but not to the volunteers. Computed tomography scanning was performed two to three times until the air reached the colon. Two examiners reconstructed multi‐planar reformation, volume rendering and virtual endoscopy. These images were compared with double balloon enteroscopic findings and/or resected specimens. Results: There were no complications associated with this examination. In the volunteers the difference between the circular folds of the jejunum and those of the ileum was clearly visualized on virtual endoscopy. Angiodysplasia (9 mm), gastrointestinal stromal tumor (15 mm) and arteriovenous malformation were clearly detected by virtual endoscopy. In contrast, one tumor could not be detected because of inadequate intestinal distension. In the two suspected cases of the stenosis, the lesion was not identified because stenotic lesions were not differentiated from normal peristalsis of the small bowel. Conclusions: Air is a feasible enteral contrast material for virtual enteroscopy.