Abstract

Patients with manifest atrioventricular accessory pathways (mAPs) have a greater tendency to develop atrial fibrillation (AF) compared with patients with concealed atrioventricular accessory pathways (cAPs). However, the risk factors of developing AF in patients with various atrioventricular accessory pathways (APs) are not clear. This retrospective study included 460 symptomatic patients with either cAPs (n = 246) or mAPs (n = 214) who underwent electrophysiological study and successful radiofrequency catheter ablation of APs. Clinical and electrophysiological characteristics were compared between cAPs and mAPs and between AF and non-AF groups with cAPs or mAPs. Independent risk factors of AF were analyzed using multivariate logistic regression. AF was more frequent in mAPs group than in cAPs group (23.4% vs 9.8%, p < 0.01). Clinical features were similar between cAPs and mAPs. Anterograde conduction properties served as the major electrophysiological feature of mAPs. Multivariate analysis indicated that mAPs, hypertension, post-ablation P wave dispersion (Pd), N-terminal proB-type natriuretic peptide (NT-proBNP) and creatinine were independent risk factors of AF in the complete cohort. Hypertension, post-ablation Pd and high-sensitivity C-reactive protein (hsCRP) were independent risk factors of AF in cAPs group. Post-ablation Pd, NT-proBNP, creatinine and shorter effective refractory period of anterograde accessory pathways (AAP ERP) were independent risk factors of AF in mAPs group. Results from this study demonstrate that the risk factors of AF are not homogenous between concealed and manifest APs, which might suggest heterogeneous pathogenesis of AF in these two types of APs.

Abstract

We hypothesized that pulmonary vein (PV) orientation influences tissue contact of the contact force (CF) sensing radiofrequency ablation catheter (CFC) and therefore atrial fibrillation (AF) free survival after pulmonary vein isolation (PVI). The aim of this study was to determine the association between PV orientation, CF and AF free survival in patients undergoing CFC PVI. Sixty consecutive patients undergoing CFC PVI were included. ECG-triggered cardiac CT scans were obtained in all patients before PVI, and the PV orientation was measured at the insertion in the LA for all PVs in both the transverse and frontal plane. PVs were assigned to 1 of 4 orientation groups: ventral–caudal, dorsal–caudal, ventral–cranial and dorsal–cranial. Mean age was 59 years, 88% had paroxysmal AF. AF free survival off anti-arrhythmic drugs after a median follow-up of 12 months was 58% after a single PVI procedure. No association was found between PV orientation and CF. Furthermore, no association was found between PV orientation and AF free survival. In univariate analysis, the number of lesions with a mean CF of 10 g was associated with AF free survival. However, in multivariate analysis, only the AF duration was significantly associated with AF free survival. This study shows that in patients undergoing PVI with the CFC ablation system, PV orientation does not affect CF and is not associated with AF free survival. PV orientation assessment does not appear to be necessary in patients undergoing CFC PVI.

Abstract

Pulmonary vein isolation (PVI) for atrial fibrillation (AF) is performed with the endoscopically assisted laser balloon ablation system (EAS). We hypothesized that placement of a circular mapping catheter (CMC) in the pulmonary vein (PV) distal to the laser balloon during ablation is feasible and safe. Out of 58 included patients, 37 underwent mapping-guided EAS PVI, with the CMC inside the PV during laser ablation, and 21 patients underwent standard EAS PVI, with the CMC outside the PV during laser ablation. Mean age was 56 years and 81% had paroxysmal AF. In the mapping-guided ablation group, 91% of PVs were isolated with the CMC in the PV during EAS ablation, isolation was completed in 9% of PVs after the CMC was removed from the PV. After passing a learning curve in 18 patients, a significant drop in unsuccessfully isolated PVs was observed in the mapping guided EAS PVI group (15% to 4%, P = 0.020). No major complications were seen in the mapping-guided EAS PVI group. However, in the standard EAS PVI group, laser ablation was complicated by a temporary phrenic nerve palsy in 1 patient. After a median follow-up of 16.7 months, there was no statistical difference in AF free survival among treatment groups (mapping-guided: 56% vs. 52%, P = 0.875). Mapping guided EAS PVI with a distal CMC in the PV during laser ablation is feasible and seems safe as the standard EAS PVI approach.

Abstract

We determined the effectiveness of the HATCH score in patients with typical atrial flutter (AFl) undergoing cavotricuspid isthmus (CTI) ablation to predict long-term atrial fibrillation (AF). We conducted an observational retrospective single-center cohort study including all patients admitted to our hospital for a CTI ablation between 1998 and 2010. The patients were divided into four categories: 1) new-onset AF (no prior AF and AF during follow-up (FU)), 2) old AF (prior AF and no AF during FU), 3) prior and post AF (AF prior and post CTI ablation), and 4) no AF. Four hundred and eight patients were included. In patients without prior AF, the hazard ratio (HR) for new-onset AF during FU was 0.98 (CI 95%: 0.65–1.50, p = 0.95) and 1.00 (CI 95%: 0.57–1.77, p = 0.98) for HATCH ≥ 2 and HATCH ≥ 3, respectively. In patients with prior AF, the HR for AF was 1.41 (CI 95%: 0.87–2.28, p = 0.17) and 1.79 (CI 95%: 0.96–3.35, p = 0.06), for HATCH ≥ 2 and HATCH ≥ 3, respectively. Left atrial enlargement was positively correlated with the occurrence of AF during FU, especially in the subgroup without prior AF, which had a HR of 2.44 (CI 95%: 1.35–4.40, p = 0.003), a HR of 2.88 (CI 95%: 1.36–6.10, p = 0.006) and a HR of 3.68 (CI 95%: 1.71–7.94, p = 0.001), for slight, moderate and severely dilated left atrial dimension, respectively, compared with a normal value. HATCH score did not predict AF in patients with typical AFl who underwent CTI ablation. Basal left atrium dimension could help predict new-onset AF.

Abstract

The diagnosis of thrombus in the left atrium in patients with persistent atrial fibrillation (AF) and may be inconsistent because of variability in thrombus morphology. In some cases it is challenging and requires unusual approach. New Doppler-derived methods might be helpful to identify such thrombi. We evaluated quantitative differences in mechanical function of the left atrial appendage (LAA) basal segments using tissue Doppler imaging (TDI)and speckle tracking echocardiography (STE) in patients with non-valvular AF with and without LAA thrombus and compared them with SR patients. A total of 80 patients with normal left ventricular ejection fraction underwent transesophageal echocardiography (40 patients with SR and 40 patients with AF on oral anticoagulants including patients with LAA thrombus). We analyzed the basal segments of LAA including left lateral ridge (LLR) and baso-medial appendage segment (BMAS). Quantitative analysis was used to calculate peak velocity, average velocity, strain, strain rate and deformation. In patients with AF the lower LLR strain rate was the sole new STE significant parameter differentiating patients with and without LAA thrombi: − 0.9(− 1.2, − 0.1)s− 1 vs. − 1.6(− 1.9, − 1.3)s− 1, (p = 0.004). Additionally, patients in SR demonstrated significantly better peak velocity, average velocity, strain, strain rate and deformation than those with AF (p < 0.001). LLR appeared to be an appropriate site for measuring Doppler derived parameters. It is possible that the strain rate in LLR area may be a novel parameter correlating with the presence of thrombus in patients with AF.

Abstract

With the publication of the 2014 Focused Update of the Canadian Cardiovascular Society Guidelines for the Management of Atrial Fibrillation, the Canadian Cardiovascular Society Atrial Fibrillation Guidelines Committee has introduced a new triage and management algorithm, the so-called “CCS Algorithm”. The CCS Algorithm is based upon expert opinion of the best available evidence, however, the CCS Algorithm has not yet been validated. Accordingly, the purpose of this study is to evaluate the performance of the CCS Algorithm in a cohort of real world patients. We compared the CCS Algorithm with the European Society of Cardiology (ESC) Algorithm in 172 hospital inpatients who are at risk of stroke due to non-valvular atrial fibrillation in whom anticoagulant therapy was being considered. The CCS Algorithm and the ESC Algorithm were concordant in 170/172 patients (99% of the time). There were two patients (1%) with vascular disease, but no other thromboembolic risk factors, which were classified as requiring oral anticoagulant therapy using the ESC Algorithm, but for whom ASA was recommended by the CCS Algorithm. The CCS Algorithm appears to be unnecessarily complicated in so far as it does not appear to provide any additional discriminatory value above and beyond the use of the ESC Algorithm, and its use could result in under treatment of patients, specifically female patients with vascular disease, whose real risk of stroke has been understated by the Guidelines.

Abstract

Left atrial appendage (LAA) thrombus is an accepted risk factor for ischemic stroke. Following a literature review we were unable to identify a study that determined the incidence of ischemic stroke in patients with a confirmed LAA thrombus. The purpose of this study was to establish the incidence of ischemic stroke in patients with a LAA thrombus confirmed on trans-oesophageal echocardiography (TOE). A ten year retrospective single centre study was conducted for the period March 2005 to February 2014 in St. Vincents University Hospital, Ireland. All TOE studies performed during this period were reviewed. A chart review was carried out on any patient who had a LAA thrombus, left atrial (LA) thrombus or pre-thrombus state identified. Charts were reviewed for documented neurological deficits consistent with ischemic stroke or transient ischemic attack within six months following TOE study. Overall 1903 TOE studies were reviewed. A total of 67 TOE studies detected a LAA thrombus, LA thrombus or pre-thrombus state. In the days prior to TOE, an ischemic stroke had occurred in two of the patients. Following detection of thrombus or pre-thrombus state on TOE and optimization of oral anti-coagulation (OAC), no patient had an ischemic stroke over the subsequent six months. This is the only study to date that has looked at the incidence of ischemic stroke following a confirmed LAA thrombus, LA thrombus or pre-thrombus state. This single centre study found low stroke rates over a six month follow-up period in patients with a confirmed LAA thrombus, LA thrombus or pre-thrombus state and optimization of OAC. Larger studies would be required to confirm these findings.