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.     

A randomised comparison of Cartomerge vs. NavX fusion in the catheter ablation of atrial fibrillation: The CAVERN Trial

Purpose

Integration of a 3D reconstruction of the left atrium into cardiac mapping systems can aid catheter ablation of atrial fibrillation (AF). The two most widely used systems are NavX Fusion and Cartomerge. We aimed to compare the clinical efficacy of these systems in a randomised trial.

Methods

Patients undergoing their first ablation were randomised to mapping using either NavX fusion or CartoMerge. Pulmonary vein isolation by wide area circumferential ablation was performed for paroxysmal AF with additional linear and fractionated potential ablation for persistent AF. Seven-day Holter monitoring was used for confirmation of sinus rhythm maintenance at 6?months.

Results

Ninety-seven patients were randomised and underwent a procedure. There was no difference in the primary endpoint of freedom from arrhythmia at 6?months (51% in the Cartomerge group vs. 48% in the NavX Fusion group, p?=?0.76). 3D image registration was faster with Cartomerge (24 vs. 33?min, p?=?0.0001), used less fluoroscopic screening (11 vs. 15?min, p?=?0.039) with a lower fluoroscopic dose (840 vs. 1,415?mGyCm², p?=?0.043). There was a strong trend to lower ablation times in the Cartomerge group, overall RF time (3,292?s vs. 4,041, p?=?0.07). Distance from 3D lesion to 3D image shell was smaller in the Cartomerge group (2.7?±?1.9 vs. 3.3?±?3.7?mm, p?Conclusions Cartomerge appears to be faster and uses less fluoroscopy to achieve registration than NavX Fusion, but overall procedural times and clinical outcomes are similar.     

Association of rs11643718 SLC12A3 and rs741301 ELMO1 Variants with Diabetic Nephropathy in South Indian Population

This study reports on the association of genetic variants selected from previous genome‐wide association studies for type 2 diabetic nephropathy in south Indians. Eight variants were genotyped in 601 type 2 diabetic subjects without nephropathy (DM) and 583 type 2 diabetic subjects with nephropathy (DN) by MassARRAY. The minor allele frequencies of rs11643718 SLC12A3 variant and rs741301 ELMO1 variant were significantly different between DM and DN groups (P = 0.029 and 0.016, respectively). A combined analysis showed that the subjects carrying the risk genotypes of both these variants (GG of rs11643718 + AG/AA of rs741301) had a significant association with DN with an odds ratio [adjusted for age, sex, Body Mass Index (BMI), HbA1c, and systolic Blood Pressure (BP)] of 1.73 (1.30–2.30, P = 1.72 × 10^–4) as compared to subjects carrying all other genotype combinations. This is the first study to report a significant association of the SLC12A3 rs11643718 and ELMO1 rs741301 (Single nucleotide Polymorphism) SNPs with diabetic nephropathy in south Indians.     

Ultrastructural changes during spermatogenesis,biochemical and hormonal evidences of testicular toxicity caused by TBT in freshwater prawn Macrobrachium rosenbergii (De Man, 1879)

The present investigation documents the impact of tributyltin (TBT) on the ultrastructural variation of spermatogenesis in freshwater prawn Macrobrachium rosenbergii. The environmentally realistic concentration of TBT can cause damages to the endocrine and reproductive physiology of crustaceans. In this context, three concentrations viz. 10, 100, and 1000 ng/L were selected and exposed to prawns for 90 days. The TBT exposed prawn exhibited decrease the reproductive activity as evidenced by sperm count and sperm length compared to control. Histopathological results revealed the retarded testicular development, abnormal structure of seminiferous tubule, decrease in the concentration of spermatozoa, diminution of seminiferous tubule membrane, abundance of spermatocytes and vacuolation in testis of treated prawns. Ultrastructural study also confirmed the impairment of spermatogenesis in treated prawns. Furthermore, radioimmunoassay (RIA) clearly documented the reduction of testosterone level in TBT exposed groups. Thus, TBT substantially reduced the level of male sex hormone as well as biochemical constituents which ultimately led to impairment of spermatogenesis in the freshwater male prawn M.rosenbergii. © 2013 Wiley Periodicals, Inc. Environ Toxicol 29: 1171–1181, 2014.     

Ceftriaxone-Resistant Salmonella enterica Serotype Typhimurium Sequence Type 313 from Kenyan Patients Is Associated with the blaCTX-M-15 Gene on a Novel IncHI2 Plasmid

Multidrug-resistant bacteria pose a major challenge to the clinical management of infections in resource-poor settings. Although nontyphoidal Salmonella (NTS) bacteria cause predominantly enteric self-limiting illness in developed countries, NTS is responsible for a huge burden of life-threatening bloodstream infections in sub-Saharan Africa. Here, we characterized nine S. Typhimurium isolates from an outbreak involving patients who initially failed to respond to ceftriaxone treatment at a referral hospital in Kenya. These Salmonella enterica serotype Typhimurium isolates were resistant to ampicillin, chloramphenicol, cefuroxime, ceftriaxone, aztreonam, cefepime, sulfamethoxazole-trimethoprim, and cefpodoxime. Resistance to β-lactams, including to ceftriaxone, was associated with carriage of a combination of bla_CTX-M-15, bla_OXA-1, and bla_TEM-1 genes. The genes encoding resistance to heavy-metal ions were borne on the novel IncHI2 plasmid pKST313, which also carried a pair of class 1 integrons. All nine isolates formed a single clade within S. Typhimurium ST313, the major clone of an ongoing invasive NTS epidemic in the region. This emerging ceftriaxone-resistant clone may pose a major challenge in the management of invasive NTS in sub-Saharan Africa.