Arrhythmia Recurrence In Patients Research Articles

P1369Predictors of atrial fibrillation recurrence after radiofrequency ablation in patients with chronic heart failure with preserved ejection fraction

Abstract Introduction. Randomized controlled trials and meta-analyzes have shown high efficacy of the radiofrequency ablation (RFA) for both initial and secondary strategies after unsuccessful drug therapy (DT) to maintain sinus rhythm (SR) and improve functional and morphological quality of life; in patients with chronic heart failure (CHF), RFA were associated with a significant relative reduction in the risk of overall mortality, atrial fibrillation (AF) recurrence, and hospitalization for cardiac pathology (compared with DT). High risk of arrhythmia recurrence (up to 45% within 6 - 12 months after intervention) remains a major RFA problem. Purpose. to evaluate predictive properties of demographic, hemodynamic and electrocardiographic parameters for recurrence after atrial fibrillation ablation in patients with chronic heart failure with preserved ejection fraction. Methods. We included 120 patients, aged 59.80 ± 10.08 years with CHF with preserved ejection fraction (EF) of left ventricle (LV) who underwent first time RFA for AF with LV EF(> 40%) I-III FC NYHA. Baseline clinical data, ECG before and after the procedure, ECHO parameters were collected Results Thirty-two patients had AF recurrence after a mean follow-up of twelve months. Those experiencing recurrence were more female (50% vs.39%, p <0,01), had a longer QTc interval before ablation than those without recurrence (387,23 ± 2,31 vs. 341,22 ± 8,91 ms, p < 0,01) and after ablation (439,01 ± 4,73 vs. 373,21 ± 7,92 ms, p < 0,001), lower LV EF (59% vs. 63%, p < 0,05), higher left atrium diameter (4,59 ± 0,45 vs. 4,08 ± 0,61 cm, p < 0,001) and higher mean pulmonary artery gradient (32,86 ± 9,67 vs. 25,15 ± 9,73, p < 0,01). Conclusions. QTc duration to radiofrequency ablation and its prolongation after intervention are independent predictors of arrhythmia recurrence in patients with chronic heart failure with a preserved left ventricular ejection fraction. The size of the left atrium before ablation is a highly sensitive predictor of recurrence of arrhythmia

Arrhythmia recurrence is more common in females undergoing multiple catheter ablation procedures for persistent atrial fibrillation: Time to close the gender gap

Female gender is associated with an increased recurrence of atrial fibrillation (AF) after catheter ablation (CA). Although AF is more common in men, women constitute a significant proportion with persistent atrial fibrillation (PsAF). The purpose of this study was to determine whether multiple ablation procedures improves arrhythmia outcomes in females with PsAF compared to men. We performed a multicenter observational study to determine long-term arrhythmia outcomes in patients undergoing >1 CA for PsAF. CA involved pulmonary vein (PV) isolation with additional ablation including linear, posterior wall isolation, electrogram-guided, or a combination of these. A total of 281 patients had >1 ablation procedure for PsAF and were included in this analysis (mean age 58.7 ± 9.3 years; 86 [30.6%] female; left atrial [LA] area 27.0 ± 5.3 cm2; PsAF duration 1.7 ± 1.7 years). At mean follow-up of 45.5 ± 31.8 months, freedom from recurrent AF was present in 148 patients(52.7%) after 2.2 ± 0.5 procedures. After multivariate analysis, female gender (hazard ratio [HR] 2.10; P <.001) and enduring PV isolation (HR 1.64; P = .01) were independently associated with AF recurrence. Enduring PV isolation was significantly higher in women than in men (33.7% vs 19.5%; P = .01). Female gender was independently and strongly associated with arrhythmia recurrence in patients undergoing multiple procedures for PsAF. PV reconnection was less likely, and fewer reconnected PVs occurred in women. Further studies are required to better understand the mechanisms responsible for AF in females to assist in closing the gender gap in the success of CA.

Very late arrhythmia recurrences in patients with sinus rhythm within the first year after catheter ablation: The Leipzig Heart Center AF Ablation Registry.

Arrhythmia recurrences after catheter ablation of atrial fibrillation (AF) still remain an important management issue. Recently, the APPLE score had been introduced to predict rhythm outcomes within 12 months after catheter ablation, while the simple MB-LATER score was developed for the prediction of very late recurrence of AF (VLRAF) occurring after 12 months. The aim of this study was to compare APPLE and MB-LATER scores in predicting VLRAF. The study population included arrhythmia-free patients within first 12 months after first radiofrequency catheter ablation from The Heart Center Leipzig AF Ablation Registry. The APPLE [one point for Age >65 years, Persistent AF, imPaired eGFR <60 mL/min/1.73 m2, Left atrial (LA) diameter ≥43 mm, EF <50%] and MB-LATER scores [one point for Male gender, Bundle branch block or QRS >120 ms, LA diameter ≥47 mm, AF Type (persistent AF), Early Recurrence <3 months] were calculated before and 3 months after ablation, respectively. We followed 482 patients {age 61 [interquartile range (IQR) 54-68] years, 66% males, 32% persistent AF} for median 40 (IQR 35-50) months. There were 184 patients (38.3%) with arrhythmia recurrences within 13-60 months after ablation. On multivariate analysis, APPLE [odds ratio (OR) 1.517, 95% confidence interval (CI) 1.244-1.850, P < 0.001] and MB-LATER (OR 1.437, 95% CI 1.211-1.705, P < 0.001) scores and diabetes mellitus (OR 2.214, 95% CI 1.353-3.625, P = 0.002) were significantly associated with arrhythmia recurrences. Receiver operating characteristic curve analyses demonstrated moderate prediction for both scores [area under the curve (AUC) 0.607, P < 0.001 for APPLE score, AUC 0.604, P < 0.001 for MB-LATER]. Prediction of VLRAF is similar for both APPLE and MB-LATER scores. A better score remains still a clinical unmet need.

Management of arrhythmia recurrence in patients with pulmonary vein stenosis following atrial fibrillation ablation.

Arrhythmia recurrence is a common clinical problem in patients with pulmonary vein stenosis (PVS) following catheter ablation of atrial fibrillation. The study sought to analyse the management of arrhythmia recurrence in patients with PVS. Retrospective analysis was performed on 29 patients with high-degree PVS. Follow-up contained clinical visits, Holter-electrocardiogram recordings and invasive pulmonary vein (PV) angiography and electrophysiological studies. Arrhythmia recurrence was observed in 18 patients (62%) after PVS formation. Fifteen of 18 patients (83.3%) with and 1 of 11 patients (9.1%) without arrhythmia recurrence had electrical PV reconnection (P = 0.0003). In 14 of 16 patients repeat pulmonary vein isolation (PVI) was conducted (radiofrequency ablation in 12 and cryoballoon ablation in 2 cases). Repeat PVI was successful in all PVs in nine patients and incomplete in five patients (failed attempt in two patients with stent implantation, no attempt in three patients with stenotic PVs). Freedom from arrhythmia recurrence was estimated at 56.3% [95% confidence interval (CI) 36.4-72.0%] after 24 months. At the end of the follow-up, complete PVI was documented in 19 of 23 patients (82.6%) with stable sinus rhythm and in 2 of 6 patients with arrhythmia recurrence (33.3%) (P = 0.0335). The Kaplan-Meier estimate of recurrence-free survival of restenosis after interventional PVS treatment was similar in patients without and with repeat ablation [75.6% (95% CI 57.0-94.3%) and 67.0% (95% CI 43.2-90.7%) after 500 days, P = 0.77]. Pulmonary vein reconnection is the major driver of arrhythmia recurrence in PVS patients. Repeat PVI is feasible and does not lead to progression of PVS or restenosis if the procedure is carefully performed.

Effect of Postablation Statin Treatment on Arrhythmia Recurrence in Patients With Paroxysmal Atrial Fibrillation.

Statins have been proposed as a means to prevent postablation atrial fibrillation (AF) recurrences, mainly on the basis of their pleiotropic effects. The objective of this subanalysis of a prospectively randomized controlled study population of patients undergoing radiofrequency ablation for paroxysmal AF was to test the hypothesis that statin treatment is associated with longer time to recurrence. This is a subanalysis over an extended follow-up period of a prospective randomized study (ClinicalTrials.gov Identifier NCT01791699). Among 291 patients, 2 propensity score-matched subgroups of patients who received or did not receive statins after pulmonary vein isolation were created. In the unmatched cohort, there was no difference in the rate of recurrence between statin-treated and not treated patients, with a 1-year recurrence estimate of 19% and 23%, respectively (Gehan statistic 0.59, P = 0.443). In the propensity-matched cohort (N = 166, 83 per group), recurrence-free survival did not differ significantly between groups (839 days, 95% confidence interval 755-922 days, in the no statin group vs. 904 days, 95% confidence interval 826-983 in the statin group; P = 0.301). The 1-year recurrence rate estimate was 30% in the no statin group versus 27% in the statin group (Gehan statistic 0.56, P = 0.455). Statin treatment does not seem to affect AF recurrence in following radiofrequency ablation for paroxysmal AF, over a follow-up time of about 2.5 years.

P6463Association of left atrial strain with arrhythmia recurrences in patients with persistent atrial fibrillation undergoing cardioversion

P6463Association of left atrial strain with arrhythmia recurrences in patients with persistent atrial fibrillation undergoing cardioversion

ФЕНОТИПОВІ ОЗНАКИ І ПОЛІМОРФІЗМ RS10465885 ГЕНА КОНЕКСИНУ-40 ЯК ПРЕДИКТОРИ ВИНИКНЕННЯ РЕЦИДИВУ АРИТМІЇ У ПАЦІЄНТІВ З ФІБРИЛЯЦІЄЮ ПЕРЕДСЕРДЬ НЕКЛАПАННОГО ҐЕНЕЗУ ПІСЛЯ ВІДНОВЛЕННЯ СИНУСОВОГО РИТМУ ПРИ 1-РІЧНОМУ СПОСТЕРЕЖЕННІ: РЕЗУЛЬТАТИ НЕЙРОМЕРЕЖЕВОГО АНАЛІЗУ

Atrial fibrillation (AF) is a violation of the heart rhythm associated with 1 % (or even more) of the health budget expenditure in Europe. Despite the fact that there is a constant increase in the socio-economic burden of AF, and there has been significant progress in understanding the pathophysiology of this arrhythmia, the effectiveness of its treatment is still far from satisfactory. One of the reasons for the insufficient effectiveness of modern strategies for the prevention and treatment of AF is the existence of limitations in understanding the complex pathophysiology of this disturbance of the heart rhythm.The aim of the study – to leran the phenotypic and genotypic (rs10465885 polymorphism in connexin-40 [Cx40] gene) predictors of arrhythmia recurrence in patients with non-valvular atrial fibrillation (AF) after sinus rhythm restoring (SRR ) at 1-year follow-up (AF360), in particular by the use of artificial neural networks (ANN ) analysis.Materials and Methods. We enrolled 104 patients (pts) with non-sustained non-valvular AF (average age (53±10) years, 80 (76.9 %) men). The distribution of rs10465885 polymorphic variants in Cx40 gene (n=73) was as follows: TT – 17 (23.3 %) pts, CT – 33 (45.2 %), СС – 23 (31.5 %). We analyzed 122 cases of SR restoring: 32 (26.2 %) – pharmacological cardioversion (29 pts); 63 (51.6 %) – electrical cardioversion (53 pts); 27 (22.2 %) – radiofrequency catheter ablation (22 pts). AF360 occurred in 76 (65.5 %) of 116 cases. In order to identify AF360 predictors, we used logistic regression analysis, as well as ANN analysis (building the linear [LIN] and nonlinear [multilayer perceptron (MLP )] ANN`s).Results and Discussion. Genetic algorithm Input Selection revealed 16 parameters, associated with AF360, including SRR type, rs10465885 polymorphism, and certain clinical (in particular, CHA 2DS 2-VAS c score), lab and echo parameters. CHA 2DS 2-VAS c score was the only independent AF360 predictor, according to the results of multivariable logistic regression analysis. The area under curve (AU C) for MLP , included all 16 variables, revealed by the Genetic algorithm, was significantly higher than in linear LIN: 0.874 (95 % confidence interval [CI] 0.798–0.929) vs. 0.678 (CI 0.583–0.763), respectively (p&lt;0.001). In order to obtain the maximal reduction of predictors, we built the MLP , included the set of 5 variables (MLP 5): SRR type; rs10465885 polymorphism; the heart failure presence and its stage; AF type (recurrent or first diagnosed); and antero-posterior left atrial dimension. MLP 5 AU C (0.808 (95 % CI 0.723–0.876)) was significantly higher than those for LIN (р = 0.027).Conclusion. AF360 was non-linearly associated with SRR type, rs10465885 polymorphism in Cx40 gene, as well as certain phenotypic parameters. The further search of the most significant genetic and epigenetic predictors of AF recurrence at different terms after SRR is of crucial importance.

Diagnostic Accuracy of a Novel Mobile Phone Application for the Detection and Monitoring of Atrial Fibrillation

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in adults, associated with significant morbidity, increased mortality, and rising health-care costs. Simple and available tools for the accurate detection of arrhythmia recurrence in patients after electrical cardioversion (CV) or ablation procedures for AF can help to guide therapeutic decisions. We conducted a prospective, single-center study to evaluate the accuracy of Cardiio Rhythm Mobile Application (CRMA) for AF detection. Patients >18 years of age who were scheduled for elective CV for AF were enrolled in the study. CRMA finger pulse recordings, utilizing an iPhone camera, were obtained before (pre-CV) and after (post-CV) the CV. The findings were validated against surface electrocardiograms. Ninety-eight patients (75.5% men), mean age of 67.7 ± 10.5 years, were enrolled. No electrocardiogram for validation was available in 1 case. Pre-CV CRMA readings were analyzed in 97 of the 98 patients. Post-CV CRMA readings were analyzed for 92 of 93 patients who underwent CV. One patient left before the recording was obtained. The Cardiio Rhythm Mobile Application correctly identified 94 of 101 AF recordings (93.1%) as AF and 80 of 88 non-AF recordings (90.1%) as non-AF. The sensitivity was 93.1% (95% confidence interval [CI] = 86.9% to 97.2%) and the specificity was 90.9% (95% CI = 82.9% to 96.0%). The positive predictive value was 92.2% (95% CI = 85.8% to 95.8%) and the negative predictive value was 92.0% (95% CI = 94.8% to 95.9%). In conclusion, the CRMA demonstrates promising potential in accurate detection and discrimination of AF from normal sinus rhythm in patients with a history of AF.

Predictors of arrhythmia recurrence in patients with heart failure undergoing left atrial ablation for atrial fibrillation.

Atrial fibrillation (AF) ablation is increasingly used in patients with reduced left ventricular ejection fraction (LVEF). The aim of the present study was to evaluate the long-term results of a single radiofrequency catheter ablation procedure in heart failure (HF) patients with AF. We tested the hypothesis that left atrial ablation is an effective therapeutic modality in patients with heart failure. Our study included HF patients with LVEF <50% who underwent catheter ablation for AF at our department between January 2010 and March 2017. All patients underwent our institution's protocol for follow-up post-ablation. The study enrolled a total of 38 patients (mean age, 54.1 ± 12.2 years; 28 [73.7%] males; mean LVEF, 38.2% ± 6.3%). After a mean follow-up period of 38.2 months (range, 5-92 months), 28 patients (73.7%) were free from arrhythmia recurrence. In multivariate analysis, early arrhythmia recurrence (P = 0.03) and amiodarone antiarrhythmic drug administration (P = 0.003) remained independent predictors of arrhythmia recurrence. The main findings of this study are that (1) a single radiofrequency catheter ablation procedure is an effective and safe modality for AF in patients with concomitant HF; (2) after a mean 3.3 years of follow-up, 73.7% of HF patients remained in sinus rhythm; and (3) early arrhythmia recurrence was a significant predictor of arrhythmia recurrence after the blanking period.

Hybrid procedures for persistent atrial fibrillation: necessity and timing of the catheter ablation stage.

In our recent paper (1) we tried to identify predictors of arrhythmia recurrence in patients undergoing a hybrid ablation procedure consisting of both an epicardial and endocardial radiofrequency (RF) ablation, performed in a delayed sequential manner, in patients with persistent atrial fibrillation (AF), with the majority presenting with long-standing persistent arrhythmia (87%). By design, our cohort of patients consisted of one of the “less curable” forms of arrhythmia, especially if treated using only conventional catheter ablation techniques. The majority of our patients might very well have been precluded from receiving invasive therapy if they had been assessed just for a catheter ablation, particularly in less experienced centers.

Predictors of Left Atrial Thrombus and Short-Term Recurrence of Arrhythmia in Patients Undergoing Electrical Cardioversion for Atrial Fibrillation, a Single-Centre Experience

Background: Systemic thromboembolism is a serious complication of electrical cardioversion. Even in the absence of such complications there exists a significant rate of arrhythmia recurrence post cardioversion. Aims: The aim of this study was to identify factors that may aid clinicians in identifying those patients at increased risk of atrial thrombus formation and short-term arrhythmia recurrence. Methods: One-hundred and twelve patients were retrospectively identified across a 2.5 year period as having undergone electrical cardioversion at the Gold Coast University Hospital for atrial fibrillation or atrial flutter. Demographic, clinical and echocardiogram data was analysed to identify potential predictors of thrombus, unsuccessful cardioversion and arrhythmia recurrence. Results: Cardioversion was successful in 87.6% of patients. Cardioversion was more successful initially in males (p&lt;0.01) and those with reduced atrial volume (p&lt;0.01) and higher left ventricular ejection fraction (p&lt;0.01). Arrhythmia recurrence within 3 months occurred in 57.7% of patients. Recurrence was more likely in those with congestive heart failure (p&lt;0.05) and a longer pre-cardioversion duration of arrhythmia (p&lt;0.05). Spontaneous echo contrast was observed in 3 (2.6%) of patients, whilst left atrial thrombus was observed in 7 (6.2%) of patients. Potential predictors of thrombus were congestive heart failure (p&lt;0.05) and increased left atrial volume (p&lt;0.01). Conclusions: This retrospective study identified a number of factors that may useful in the clinical setting in predicting cardioversion success, both initially and short-term, in addition to predicting thrombus formation.

Arrhythmia recurrence in patients following cardiac surgery with concomitant therapy of atrial fibrillation – Experience of our cardiac center

IntroductionSurgical treatment of atrial fibrillation (AF) is a common and time-proven treatment method for this type of arrhythmias both as a separate procedure and as a procedure related to cardiac surgery for another indication (concomitant procedure). Patients experience arrhythmia recurrence despite highly efficient surgical treatment. These arrhythmias are often resistant to pharmacological treatment (due to an extensive fibrous substrate); therefore, electroanatomical mapping accompanying catheter ablation is significantly more effective. The arrhythmogenic fibrous substrate is a result of both a primary cardiac disease (an underlying disease causing atrial dilation) and surgical intervention (incision, cannula insertion sites, MAZE lines with a renewed spread of electrical signal in these blocks). Method and patientsElectroanatomical mapping and ablation were performed in 92 patients with arrhythmia recurrence following concomitant surgical treatment for AF between January 2010 and November 2015. The Cox maze procedure was performed using a disposable cryoablation catheter. The heart rhythm in patients following radiofrequency ablation procedure was monitored in half-year intervals (24-h Holter ECG, 7-day loop recorder, in some patients also by means of implanted pacemakers or implantable loop recorders). The average left atrial size (PLAX) was 50mm, 59% of patients underwent mitral valve surgery, 54% of patients had tricuspid valve surgery, 16% were operated for congenital developmental disorders, in 17% of patients, repeated cardiac surgery was performed. The above-mentioned facts show that these are patients with an extensive arrhythmogenic substrate. ResultsThe Cox maze procedure resulted in an extensive fibrous arrhythmogenic substrate in the atrium (arrhythmia recurrence following the maze procedure is more often regular atrial tachycardias while AF is predominant among arrhythmias for which the maze procedure was indicated). All patients had a follow-up visit after 12 months, 80% of patients presented for a follow-up visit after 24 months. Early recurrence after ablation (within 3 months following the procedure) was found in 21% of patients. Early recurrence after ablation was statistically significantly related to arrhythmia recurrence within 12 months (p=0.003) and arrhythmia recurrence within 24 months (p=0.003). 73% of patients had no recurrent AF or atrial tachycardia (AT) after 12 months and 53% after 24 months. A total of 146 arrhythmias were ablated, i.e. 1/3 of patients had more than 1 arrhythmia. These were persistent AF found in 24% of patients, paroxysmal AF seen in 13% of patients and regular AT detected in 53% of patients. More than one half of regular AT originated in LA (as perimitral atrial flutter in most cases). Remaining arrhythmias originated from the right atrium (as typical atrial flutter in half of the cases). 57% of patients had a renewed spread of signal in the mitral isthmus (ablation of the coronary sinus was necessary in 1/3 of patients). No domination in the number of reconnections was found for any of the pulmonary veins. The finding of a significantly reduced signal amplitude in the entire LA was associated with a higher risk of acute ablation failure (p=0.001). Acute ablation failure was associated with a higher risk of arrhythmia recurrence after 12 months (p=0.07). There was a trend of a higher AT incidence originating from the RA in patients who underwent surgery for a congenital heart defect (p=0.06). The diagnosis of arterial hypertension was associated with a higher risk of arrhythmia recurrence (p=0.13). The finding of persistent AF on ECG (compared to other findings, i.e. paroxysmal AF and regular AT) before ablation did not increase the risk of recurrence after ablation. ConclusionIn patients after cardiac surgery, catheterization performed to treat arrhythmia recurrence is a effective method of subsequent treatment, despite an extensive arrhythmogenic substrate. A rather large number of AT cases originate from the right atrium, in particular in patients after surgery for congenital heart defects. Patients with a significantly reduced signal in the larger part of the atrium due to an extensive arrhythmogenic substrate present the most complicated cases.

Family history of atrial fibrillation as a predictor of atrial substrate and arrhythmia recurrence in patients undergoing atrial fibrillation catheter ablation.

A commonly held notion is that patients with a family history of atrial fibrillation (AF) have worse atrial substrate and higher rates of arrhythmia recurrence following ablation. We sought to examine differences in atrial substrate and catheter ablation outcomes in patients with a 1st degree family member with paroxysmal or persistent AF (PeAF) compared to those without. A total of 256 consecutive patients undergoing their 1st ablation for AF (123 paroxysmal, 133 persistent) with >1 year follow up were included. The presence of one 1st-degree family relative was defined as a 'positive family history'. Clinical characteristics, electroanatomic map findings, ablation characteristics and outcomes were compared in patients with and without a positive family history of AF. Patients with paroxysmal fibrillation with a positive family history (n = 57; 46%) had similar clinical characteristics and arrhythmia recurrence after catheter ablation as those without. Of those that recurred, patients with a positive family history were more likely to have progressed to PeAF (P = 0.05). Patients with PeAF with a positive family history (n = 75; 56%) had similar clinical characteristics, electroanatomic mapping findings and ablation characteristics, but worse long term arrhythmia free survival (P = 0.04). The presence of a 1st-degree family member with AF does not impact the clinical outcomes of catheter ablation for paroxysmal AF. However, a positive family history is associated with worse arrhythmia free survival in patients with PeAF. This finding is not explained by differences in clinical characteristics, atrial substrate assessed by voltage maps or ablation characteristics.

Ablation of Complex Fractionated Electrograms With or Without ADditional LINEar Lesions for Persistent Atrial Fibrillation (The ADLINE Trial).

For persistent atrial fibrillation (AF) ablation, different strategies including complex fractionated atrial electrograms (CFAE) ablation and linear lesions (LL) have been used in addition to pulmonary vein isolation (PVI). However, it is still a matter of debate if extended substrate modification improves long-term outcome. The aim of this study was to determine the benefit of LL in addition to PVI and CFAE ablation regarding freedom from arrhythmia recurrence in patients with persistent AF. The study was a prospective randomized trial including 90 patients with persistent and longstanding persistent AF. All patients underwent PVI and CFAE ablation. If AF did not terminate to atrial tachycardia (AT) or sinus rhythm, patients were randomized to direct current cardioversion (Group 1; n = 45) or LL (Group 2; n = 45). Primary endpoint was freedom from any atrial arrhythmia off antiarrhythmic drugs at 12 months. (NCT02059369) RESULTS: Baseline characteristics were similar between the two groups with more than half of the patients having structural heart disease. The primary endpoint was reached in 37% in Group 1 (G1) and 16% in Group 2 (G2; P = 0.03). After a total number of 1.4 ± 0.5 (G1) versus 1.7 ± 0.4 (G2; P = 0.01) procedures, freedom from any arrhythmia was reached in 54% in G1 and 65% in G2 (P = 0.35). In persistent AF ablation, LL in addition to PVI and CFAE show a significantly lower success rate after a single procedure compared to PVI and CFAE. Following LL, significantly more patients needed a reablation to reach a similar success rate during a 12-month follow-up.

Predictors of Left Atrial Thrombus and Short-Term Recurrence of Arrhythmia in Patients Undergoing Electrical Cardioversion for Atrial Fibrillation, a Single-Centre Experience

Background: Systemic thromboembolism is a serious complication of electrical cardioversion. Even in the absence of such complications there exists a significant rate of arrhythmia recurrence post cardioversion. Aims: The aim of this study was to identify factors that may aid clinicians in identifying those patients at increased risk of atrial thrombus formation and short-term arrhythmia recurrence. Methods: One-hundred and twelve patients were retrospectively identified across a 2.5 year period as having undergone electrical cardioversion at the Gold Coast University Hospital for atrial fibrillation or atrial flutter. Demographic, clinical and echocardiogram data was analysed to identify potential predictors of thrombus, unsuccessful cardioversion and arrhythmia recurrence. Results: Cardioversion was successful in 87.6% of patients. Cardioversion was more successful initially in males (p&lt;0.01) and those with reduced atrial volume (p&lt;0.01) and higher left ventricular ejection fraction (p&lt;0.01). Arrhythmia recurrence within 3 months occurred in 57.7% of patients. Recurrence was more likely in those with congestive heart failure (p&lt;0.05) and a longer pre-cardioversion duration of arrhythmia (p&lt;0.05). Spontaneous echo contrast was observed in 3 (2.6%) of patients, whilst left atrial thrombus was observed in 7 (6.2%) of patients. Potential predictors of thrombus were congestive heart failure (p&lt;0.05) and increased left atrial volume (p&lt;0.01). Conclusions: This retrospective study identified a number of factors that may useful in the clinical setting in predicting cardioversion success, both initially and short-term, in addition to predicting thrombus formation.

Predictors of late atrial fibrillation recurrence after cryoballoon-based pulmonary vein isolation: a meta-analysis.

The recurrence rate of atrial fibrillation (AF) after cryoballoon ablation in drug refractory AF patients is high. Late-recurrence of AF has various predictors. The aim of the study was to explore the related risk factors that can effectively predict late AF recurrence after cryoballoon-based pulmonary vein isolation. The PubMed and Web of Science databases were searched from 1 January 2013 to 1 August 2016, and studies were chosen that met the pre-stated inclusion criteria. The reference lists of the retrieved articles were also reviewed. Two authors independently extracted information on the designs of the studies. The strength of the relationship between different risk factors and late recurrence was assessed by the adjusted hazard ratio. A total of 16 papers met the inclusion criteria and were included in the meta-analysis. The hazard ratio of late atrial arrhythmia recurrence in patients with early recurrence was 4.19 compared with the reference group (95% CI 2.73-6.44, p < 0.00001); that of increased left atrial diameter was 1.25 (95% CI 1.12-1.3, p < 0.0001); that of a long duration of AF before ablation was 1.10 (95% CI 1.04-1.17, p < 0.0009); and that of persistent AF was 2.44 (95% CI 1.30-4.58, p < 0.006). However, there exists significant heterogeneity for each indicator, and a slight publication bias was observed. Our study suggests that early recurrence in the blanking period, increased left atrial size, a longduration of AF before ablation and persistent AF are independent predictors of late recurrence after cryoballoon ablation.

Pulmonary Vein Antral Isolation and Nonpulmonary Vein Trigger Ablation Are Sufficient to Achieve Favorable Long-Term Outcomes Including Transformation to Paroxysmal Arrhythmias in Patients With Persistent and Long-Standing Persistent Atrial Fibrillation.

Transformation from persistent to paroxysmal atrial fibrillation (AF) after ablation suggests modification of the underlying substrate. We examined the nature of initial arrhythmia recurrence in patients with nonparoxysmal AF undergoing antral pulmonary vein isolation and nonpulmonary vein trigger ablation and correlated recurrence type with long-term ablation efficacy after the last procedure. Three hundred and seventeen consecutive patients with persistent (n=200) and long-standing persistent (n=117) AF undergoing first ablation were included. AF recurrence was defined as early (≤6 weeks) or late (>6 weeks after ablation) and paroxysmal (either spontaneous conversion or treated with cardioversion ≤7 days) or persistent (lasting >7 days). During median follow-up of 29.8 (interquartile range: 14.8-49.9) months, 221 patients had ≥1 recurrence. Initial recurrence was paroxysmal in 169 patients (76%) and persistent in 52 patients (24%). Patients experiencing paroxysmal (versus persistent) initial recurrence were more likely to achieve long-term freedom off antiarrhythmic drugs (hazard ratio, 2.2; 95% confidence interval, 1.5-3.2; P<0.0001), freedom on/off antiarrhythmic drugs (hazard ratio, 2.5; 95% confidence interval, 1.6-3.8; P<0.0001), and arrhythmia control (hazard ratio, 5.2; 95% confidence interval, 2.9-9.2; P<0.0001) after last ablation. In patients with persistent and long-standing persistent AF, limited ablation targeting pulmonary veins and documented nonpulmonary vein triggers improves the maintenance of sinus rhythm and reverses disease progression. Transformation to paroxysmal AF after initial ablation may be a step toward long-term freedom from recurrent arrhythmia.

Early repolarization pattern is the strongest predictor of arrhythmia recurrence in patients with idiopathic ventricular fibrillation: results from a single centre long-term follow-up over 20 years.

Idiopathic ventricular fibrillation (iVF) accounts for up to 14% of VF incidence. Data regarding long-term outcome and clinical risk markers of arrhythmia recurrence are scarce. The objective of our study was to describe a long-term follow-up (FU) of a cohort of iVF survivors in our centre during the past 20 years, and to investigate the influence of clinical parameters, e.g. presence of an early repolarization pattern (ERP), on recurrence rate of arrhythmias. Thirty-five iVF survivors were identified and retrospectively analysed regarding recurrent implantable cardioverter-defibrillator (ICD) interventions and covariates potentially influencing arrhythmia recurrence. Appropriate ICD interventions occurred in 15 patients (43%) after a median of 6.6 years during a median FU period of 8.8 years. Two patients (13%) received the first appropriate therapy after an assumed average ICD battery longevity of 7 years, while in all other patients, the first therapy occurred within the first ICD period. Appropriate interventions were observed more often and earlier in patients with ERP (HR 3.9; 1.4-11.0; P = 0.01), whereas all other covariates failed to predict subsequent events. A high incidence of inappropriate ICD therapies (67 interventions in 14 patients) could be attributed to the occurrence of atrial fibrillation (66% of all inappropriate therapies). The recurrence rate of ventricular arrhythmias in iVF survivors is high and recurrence might occur delayed (>7 years after the initial event). ERP seems to be highly predictive with respect to early arrhythmia recurrence. Our results highlight that better pathophysiologic understanding of ERP might facilitate a better risk stratification before and an optimal treatment after an iVF event. The high rate of AF and ERP in iVF survivors might indicate an underlying heart disease or myocardial electrical disorder not apparent at the index event.

Adenosine-guided pulmonary vein isolation for the treatment of paroxysmal atrial fibrillation: an international, multicentre, randomised superiority trial

Catheter ablation is increasingly used to manage atrial fibrillation, but arrhythmia recurrences are common. Adenosine might identify pulmonary veins at risk of reconnection by unmasking dormant conduction, and thereby guide additional ablation to improve arrhythmia-free survival. We assessed whether adenosine-guided pulmonary vein isolation could prevent arrhythmia recurrence in patients undergoing radiofrequency catheter ablation for paroxysmal atrial fibrillation. We did this randomised trial at 18 hospitals in Australia, Europe, and North America. We enrolled patients aged older than 18 years who had had at least three symptomatic atrial fibrillation episodes in the past 6 months, and for whom treatment with an antiarrhythmic drug failed. After pulmonary vein isolation, intravenous adenosine was administered. If dormant conduction was present, patients were randomly assigned (1:1) to additional adenosine-guided ablation to abolish dormant conduction or to no further ablation. If no dormant conduction was revealed, randomly selected patients were included in a registry. Patients were masked to treatment allocation and outcomes were assessed by a masked adjudicating committee. Patients were followed up for 1 year. The primary outcome was time to symptomatic atrial tachyarrhythmia after a single procedure in the intention-to-treat population. The trial is registered with ClinicalTrials.gov, number NCT01058980. Adenosine unmasked dormant pulmonary vein conduction in 284 (53%) of 534 patients. 102 (69·4%) of 147 patients with additional adenosine-guided ablation were free from symptomatic atrial tachyarrhythmia compared with 58 (42·3%) of 137 patients with no further ablation, corresponding to an absolute risk reduction of 27·1% (95% CI 15·9-38·2; p<0·0001) and a hazard ratio of 0·44 (95% CI 0·31-0·64; p<0·0001). Of 115 patients without dormant pulmonary vein conduction, 64 (55·7%) remained free from symptomatic atrial tachyarrhythmia (p=0·0191 vs dormant conduction with no further ablation). Occurrences of serious adverse events were similar in each group. One death (massive stroke) was deemed probably related to ablation in a patient included in the registry. Adenosine testing to identify and target dormant pulmonary vein conduction during catheter ablation of atrial fibrillation is a safe and highly effective strategy to improve arrhythmia-free survival in patients with paroxysmal atrial fibrillation. This approach should be considered for incorporation into routine clinical practice. Canadian Institutes of Health Research, St Jude Medical, Biosense-Webster, and M Lachapelle (Montreal Heart Institute Foundation).

Flecainide-induced prolongation of ventricular repolarization contributes to the proarrhythmic profile of action

Flecainide is class Ic Na + channel blocker that is used to restore sinus rhythm and to prevent the arrhythmia recurrence in patients with atrial fibrillation. Antiarrhythmic effect of flecainide is attribut- ed to prolonged atrial effective refractory period and depressed car- diac action potential upstroke. Nevertheless, flecainide has been reported to produce arrhythmogenic responses in ventricular myo- cardium. In this regard, the Cardiac Arrhythmia Suppression Trial (CAST) has shown that flecainide therapy is associated with marked- ly increased risk of sudden arrhythmic death in patients with healed myocardial infarction, an effect possibly accounted for by the drug- induced anisotropic conduction slowing in the peri-infarct zone. Based on these findings, indications for flecainide therapy are cur- rently limited to the atrial fibrillation control in patients with no structural heart disease. Although flecainide-induced conduction abnormalities are unlikely to occur in the absence of myocardial ischemia or fibrosis, there is in- creasing evidence to suggest that flecainide may promote arrhythmo- genic responses in patients with structurally normal hearts. Flecainide administration has been reported to induce torsade de pointes, a poten- tially life-threatening polymorphic ventricular tachycardia, in patients with no coronary artery disease or severe heart failure (1,2). This kind of arrhythmia is thought to be attributed to the prolonged QT interval and increased spatial dispersion of ventricular repolarization. However, the contribution of these factors to flecainide-induced proarrhythmia is often overlooked, because flecainide (along with other class Ic Na + channel blockers) is generally regarded asanagentproducingonly little or no effect on ventricular repolarization.