Search

Following atrial fibrillation (AF) ablation procedures, patients may present with atrial tachycardias (ATs) that show remarkable stability for short periods of time but degenerate in unstable forms right afterwards. In order to map these types of ATs, we applied the sequential mapping capabilities only for time segments where ATs exhibited constant cycle length (CL) and activation sequence, excluding the segments with unstable recordings. We herein describe two cases of ATs after AF ablation which were mapped with this technique that allowed for the successful identification and subsequent ablation of the tachycardia circuit. [ABSTRACT FROM AUTHOR]

Purpose: A possible consequence of atrial fibrillation (AF) ablation is the occurrence of organized atrial tachycardias (ATs). ATs after AF ablation (ATAAF) may be more symptomatic than AF itself, thus necessitating catheter ablation. We evaluated the prognostic significance of clinical and invasive characteristics for long-term sinus rhythm (SR) maintenance following ATAAF ablation and assessed the effect of technological developments on these results., Methods and Results: Fifty-six consecutive patients with symptomatic ATAAF participated in the study and 114 ATAAF were revealed (2.04 ± 0.93 per patient). Sixty-eight ATAAF (60%) were macroreentrant and 33 (29%) were microreentrant circuits, while 13 (11%) were focal automatic tachycardias. The mean follow-up was 40 ± 18 months with 34 (61%) patients maintaining SR. Treatment with contact force (CF) catheters and EnSite AutoMap module (n = 11) showed significantly better AT/AF free rates at 1-year follow-up (10/11, 91%) compared with treatment using CF catheters but not AutoMap module (n = 13) (8/13, 62%) and treatment with use of neither of these modalities (n = 32) (16/32, 50%). Among patients with macroreentrant circuits around the mitral annulus or left atrial roof (n = 38), the group treated with complete linear lesions in anatomical isthmuses (n = 25) showed significantly better SR maintenance (19/25, 76%) compared with patients (n = 13) treated by empirical ablation in critical functional areas (6/13, 46%)., Conclusions: Technology advancement contributes substantially to long-term success in SR maintenance, by achieving detailed mapping and more effective ablation of ATAAF. The targeting of macroreentrant circuits by creating anatomical linear lesions appears to provide better results.

Background: Radiofrequency (RF) ablation of the slow pathway (SP) in atrioventricular nodal reentry tachycardia (AVNRT) is occasionally complicated with atrioventricular block (AVB) often predicted by junctional beats (JB) with loss of ventriculo-atrial (VA) conduction., Methods: We analyzed retrospectively 153 patients undergoing ablation of SP for typical AVNRT. Patients were divided into two age groups: 127 ≤ 70 years and 26 > 70 years. We analyzed the interval between the atrial electrogram in the His-bundle position and the distal ablation catheter [A(H)-A(RFd)] and between the distal ablation catheter and the proximal coronary sinus catheter [A(RFd)-A(CS)] before RF applications with and without JB. We evaluated if these intervals can be used as predictors of JB incidence and also of JB with loss of VA conduction. We also assessed if age influences the risk of loss of VA conduction., Results: The A(H)-A(RFd) and A(RFd)-A(CS) intervals were significantly shorter in RF applications causing JB than those without JB (33 ± 11 ms vs 39 ± 9 ms, P < 0.001, 14 ± 9 ms vs 20 ± 7 ms, P < 0.001, respectively). The A(H)-A(RFd) and A(RFd)-A(CS) intervals were also significantly shorter in RFs causing JB with VA block than those with VA conduction (29 ± 11 ms vs 35 ± 11 ms, P < 0.001, 8 ± 8 ms vs 17 ± 8 ms, P < 0.001, respectively). Patients > 70 years had shorter intervals (36 ± 11 ms vs 29 ± 8 ms, P  =  0.012, 17 ± 8 ms vs 13 ± 7 ms, P  =  0.027, respectively), while VA block was more common in this age group., Conclusions: The A(H)-A(RFd) and A(RFd)-A(CS) intervals can be used as markers for predicting JB occurrence as well as impending AVB. JB with loss of VA conduction occur more often in older patients possibly due to a higher position of SP., (© 2017 Wiley Periodicals, Inc.)

Introduction: Atrial fibrillation (AF) is a common arrhythmia with evidence of genetic susceptibility. The rs2200733 single-nucleotide polymorphism (SNP) in a non-coding region on chromosome 4q25 has been associated with AF. The purpose of this case-control study was to examine the possible association of the rs2200733 polymorphism with AF in the Greek population., Methods: A total of 295 individuals, 167 AF patients and 128 controls, were genotyped for the presence of the rs2200733 polymorphism using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLPs) method., Results: The T/T genotype and the T allele were detected more frequently in patients with AF compared to controls (13.2% vs. 2.3%, p=0.001, and 29.6% vs. 17.9%, p=0.001), suggesting that the rs2200733 polymorphism increases susceptibility to AF in the Greek population. In a multivariate stepwise analysis that included many conventional precipitating factors for AF, T/T genotype and left atrium (LA) diameter were the only independent predictors of AF (OR 1.74, 95% CI: 1.40-2.98, p=0.005, and OR 2.88, 95% CI: 1.835.62, p<0.001, respectively). A trend of association was observed between the T/T genotype and lone AF (p=0.08)., Conclusions: Our results suggest that SNP rs2200733 confers a significant risk of AF in the Greek population, providing further support to the previously reported association between AF and rs2200733 polymorphism on chromosome 4q25.

Aims: Amiodarone is used commonly for pharmacological cardioversion of atrial fibrillation (AF), but it is limited by moderate efficacy and delayed action. Ranolazine and amiodarone are markedly synergistic in suppressing experimental AF in vitro, yet the clinical efficacy of ranolazine combined with amiodarone for AF conversion has only undergone minimal investigation. This prospective, single-blinded, randomized study compared the safety and efficacy of ranolazine added to amiodarone vs. amiodarone alone for conversion of recent-onset AF., Methods and Results: We enroled 121 patients (64 ± 10 years, 45% male) with recent-onset (<48 h duration) AF who were eligible for pharmacological cardioversion. Patients received either 24 h amiodarone infusion (loading dose 5 mg/kg followed by maintenance dose of 50 mg/h; n = 60), or amiodarone infusion at the same dosage plus a single oral dose of ranolazine 1500 mg (n = 61). Patients in the amiodarone plus ranolazine group compared with the amiodarone-only group showed significantly higher conversion rates at 24 h (87 vs. 70%, respectively; P = 0.024) and at 12 h (52 vs. 32%; P = 0.021), and shorter time to conversion (10.2 ± 3.3 vs. 13.3 ± 4.1 h; P = 0.001). Subgroup analysis identified higher 24 h conversion in patients with left atrial (LA) diameter >46 mm who received the combination treatment vs. amiodarone alone (81 vs. 54%; P = 0.02), whereas the efficacy of the two interventions did not differ among patients with LA diameter ≤46 mm (P = 0.77). There was modest QT prolongation in both the groups, no serious adverse reactions, and no pro-arrhythmic events., Conclusion: Addition of ranolazine to amiodarone was safe and well tolerated in this study, and it demonstrated efficacy superior to amiodarone alone for conversion of recent-onset AF. These findings may have clinical implications by offering a simple therapeutic manoeuvre to enhance amiodarone's effectiveness for conversion of AF., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.)

This study aimed to determine systolic dysfunction and estimate resting left ventricular ejection fraction (LVEF) from information collected during routine evaluation of patients with suspected or known coronary heart disease. This approach was then compared to gated single photon emission tomography (SPET). Patients having undergone stress (201)Tl myocardial perfusion imaging followed by equilibrium radionuclide angiography (ERNA) were separated into derivation (n=954) and validation (n=309) groups. Logistic regression analysis was used to develop scoring systems, containing clinical, electrocardiographic (ECG) and scintigraphic data, for the discrimination of an ERNA-LVEF<0.50. Linear regression analysis provided equations predicting ERNA-LVEF from those scores. In 373 patients LVEF was also assessed with (201)Tl gated SPET. Our results showed that an ECG-Scintigraphic scoring system was the best simple predictor of an ERNA-LVEF<0.50 in comparison to other models including ECG, clinical and scintigraphic variables in both the derivation and validation subpopulations. A simple linear equation was derived also for the assessment of resting LVEF from the ECG-Scintigraphic model. Equilibrium radionuclide angiography-LVEF had a good correlation with the ECG-Scintigraphic model LVEF (r=0.716, P=0.000), (201)Tl gated SPET LVEF (r=0.711, P=0.000) and the average LVEF from those assessments (r=0.796, P=0.000). The Bland-Altman statistic (mean+/-2SD) provided values of 0.001+/-0.176, 0.071+/-0.196 and 0.040+/-0.152, respectively. The average LVEF was a better discriminator of systolic dysfunction than gated SPET-LVEF in receiver operating characteristic (ROC) analysis and identified more patients (89%) with a

Background: Many criteria have been published to localize accessory pathways from the 12-lead ECG during sinus rhythm. This study analyzed whether the localization of an accessory pathway could be predicted by using the polarity of the QRS complex during sinus rhythm on the surface ECG, instead of the delta wave polarity as used in many reports., Methods: The ECGs of 140 patients with an overt and single accessory pathway were evaluated. Eight localizations were taken into account. The precise location was previously known from successful radiofrequency ablation sites., Results: In 128 patients (92%), the new algorithm allowed an accurate diagnosis of the site of implantation of the accessory pathway., Conclusion: Analysis of the polarity of the QRS complex on five electrocardiographic leads provides an easy, fast and reliable way to localize accessory pathways during sinus rhythm.

The incidence and consequences of inappropriate sinus tachycardia following modification of the AV nodal area with radiofrequency energy were prospectively studied in a consecutive series of 118 patients. Twelve (10%) patients developed this complication, which persisted less than 1 week in all but three patients. Inappropriate sinus tachycardia was only observed after fast pathway ablation. Only four patients required temporary treatment with a beta blocker.