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Background: Ablation of atrial fibrillation (AF) is one of the most time consuming procedures in interventional electrophysiology. Currently, the selection of catheters and ablation techniques is still a matter of debate. Due to the rapidly increasing demand of ablation procedures, technical advances would be helpful to reduce complexity and procedure time in AF ablation. Therefore we investigated the feasibility of a novel decapolar ablation catheter (PVAC) combined with a duty-cycled, low-power RF generator for pulmonary vein (PV) isolation. The system does not require 3D mapping and is the first to enable mapping, pacing and circular as well as segmental ablation with a single catheter. Methods: AF mapping and ablation was performed in 15 consecutive patients with intermittent AF (mean age 58±12 years, 6 males) using the PVAC- catheter. To visualize the pulmonary vein anatomy, CT or MRI scan was performed in addition to PV angiography before ablation procedure. Additionally all patients underwent transesophageal echocardiography to rule out left atrial (LA) thrombi. Ablation procedure was performed by introducing the PVAC to the LA via single transseptal puncture. An optimal and stable catheter position for mapping and ablation was achieved by using a steerable sheath and an over the wire technique. RF energy was typically delivered for 60s for circular and 30 to 60s for segmental ablations. Ablation success was defined by disappearance of PV signals and complete exit block obtained by PVAC stimulation. Results: Isolation of all four PVs could be achieved in 59/60 veins (98%). A very small and hypoplastic right inferior PV could not be reached. The median RF application time until all PV were isolated successfully was 23±7 min. First half of ablations were performed by circular RF application, second half with segmental applications until isolation. Procedure time for ablation was 81±14 min. Total fluoroscopy time was 31±9 min. There were no procedural complications. Conclusion: Mapping and ablation of pulmonary veins can be performed safe and fast, with low procedure times using a single catheter without 3D navigation or assisted steering. Thus this system may be of high interest not only for high volume but all centers performing AF ablation.

Cardiac QT interval represents both ventricular depolarization and repolarization events. Previous studies suggested significant genetic contribution to the normal QT interval length variation. In a candidate gene approach, we sought to identify novel genetic determinants of the normal QT interval length within the Ankyrin-2 (Ank-2) gene. Population and Methods: The study population consisted of 1492 participants of the WHO MONICA population survey. A standard measurement of the QT interval from the 12-lead ECG was available in 1212 individuals. The QT interval was corrected for covariates using different general and population specific formulas (QTc). Altogether, 22 SNPs within the Ank-2 gene were genotyped using the TaqMan technology. Statistical analyses included ANOVA and linear regression based trend test for comparisons of the QTc means. Results: In the promotor region of the alternative splicing Ank-2 variant, several SNPs and haplotypes were highly significantly associated with the QTc interval length. Specifically, a SNP rs1979086 (minor allele frequency f=0.44) was associated with the QTc length in the whole population (P=0.004 for ANOVA and P Conclusion: A small genomic region in the promotor of the Ank-2 gene contains SNPs and haplotypes that significantly influence the QTc interval in the normal population of German descent. A gender-specific effect with greater influence in male participants requires further evaluation.