Impact of body mass index on the outcome of catheter ablation of atrial fibrillation.

OBJECTIVES: The association between obesity and atrial fibrillation (AF) is well-established. We aimed to evaluate the impact of index body mass index (BMI) on AF recurrence at 12 months following catheter ablation using propensity-weighted analysis. In addition, periprocedural complications and fluoroscopy details were examined to assess overall safety in relationship to increasing BMI ranges. METHODS: Baseline, periprocedural and follow-up data were collected on consecutive patients scheduled for AF ablation. There were no specific exclusion criteria. Patients were categorised according to baseline BMI in order to assess the outcomes for each category. RESULTS: Among 3333 patients, 728 (21.8%) were classified as normal (BMI <25.0 kg/m2), 1537 (46.1%) as overweight (BMI 25.5-29.0 kg/m2) and 1068 (32.0%) as obese (BMI ≥30.0 kg/m2). Procedural duration and radiation dose were higher for overweight and obese patients compared with those with a normal BMI (p=0.002 and p<0.001, respectively). An index BMI ≥30 kg/m2 led to a 1.2-fold increased likelihood of experiencing recurrent AF at 12-months follow-up as compared with overweight patients (HR 1.223; 95% CI 1.047 to 1.429; p=0.011), while no significant correlation was found between overweight and normal BMI groups (HR 0.954; 95% CI 0.798 to 1.140; p=0.605) and obese versus normal BMI (HR 1.16; 95% CI 0.965 to 1.412; p=0.112). CONCLUSIONS: Patients with a baseline BMI ≥30 kg/m2 have a higher recurrence rate of AF following catheter ablation and therefore lifestyle modification to target obesity preprocedure should be considered in these patients.

Selección de lo mejor del año 2016 en aritmología clínica / Selection of the best of 2016 in clinical arrhythmology

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Ablation of Atrial Fibrillation in Combination with Left Atrial Appendage Occlusion in A Single Procedure. Rationale and Technique.

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, and is associated with a fivefold increase in the risk of ischemic stroke and systemic embolism. Left atrial appendage (LAA) is the source of thrombi in up to 90% of patients with nonvalvular atrial fibrillation (AF). Although thromboembolic prophylaxis by means of oral anticoagulants (OAC) has been shown to be very effective (OAC), they also confer an inevitably risk of serious bleeding. Catheter ablation (CA) is an effective treatment for symptomatic AF but its role in stroke prevention remains unproved. Recently, LAA percutaneous occlusion has been demonstrated to be equivalent to OACs in reducing thromboembolic events. The aim of this review is to describe the rationale, feasibility, outcomes and technique of a combined procedure of AFCA and percutaneous LAAO, two percutaneous interventions that share some procedural issues and technical requirements, in patients with symptomatic drug-refractory AF, high risk of stroke, and contraindications to OACs.

Emerging risk factors and the dose-response relationship between physical activity and lone atrial fibrillation: a prospective case-control study.

AIMS: The role of high-intensity exercise and other emerging risk factors in lone atrial fibrillation (Ln-AF) epidemiology is still under debate. The aim of this study was to analyse the contribution of each of the emerging risk factors and the impact of physical activity dose in patients with Ln-AF. METHODS AND RESULTS: Patients with Ln-AF and age- and sex-matched healthy controls were included in a 2:1 prospective case-control study. We obtained clinical and anthropometric data transthoracic echocardiography, lifetime physical activity questionnaire, 24-h ambulatory blood pressure monitoring, Berlin questionnaire score, and, in patients at high risk for obstructive sleep apnoea (OSA) syndrome, a polysomnography. A total of 115 cases and 57 controls were enrolled. Conditional logistic regression analysis associated height [odds ratio (OR) 1.06 [1.01-1.11]], waist circumference (OR 1.06 [1.02-1.11]), OSA (OR 5.04 [1.44-17.45]), and 2000 or more hours of cumulative high-intensity endurance training to a higher AF risk. Our data indicated a U-shaped association between the extent of high-intensity training and AF risk. The risk of AF increased with an accumulated lifetime endurance sport activity ≥ 2,000 h compared with sedentary individuals (OR 3.88 [1.55-9.73]). Nevertheless, a history of <2000 h of high-intensity training protected against AF when compared with sedentary individuals (OR 0.38 [0.12-0.98]). CONCLUSION: A history of ≥ 2,000 h of vigorous endurance training, tall stature, abdominal obesity, and OSA are frequently encountered as risk factors in patients with Ln-AF. Fewer than 2000 total hours of high-intensity endurance training associates with reduced Ln-AF risk.

Gastroparesia: una complicación poco reconocida de la ablación percutánea de la fibrilación auricular / Gastroparesis: An under-recognized complication after atrial fibrillation catheter ablation procedure

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Combined catheter ablation and left atrial appendage closure as a hybrid procedure for the treatment of atrial fibrillation.

AIMS: Left atrial appendage (LAA) is the source of thrombi in up to 90% of patients with non-valvular atrial fibrillation (AF). Catheter ablation (CA) is an effective treatment for symptomatic AF and, in selected cases, LAA occlusion devices have been introduced as an alternative to oral anticoagulants (OACs). The safety and feasibility of combining CA and percutaneous LAA closure (LAAC) are unknown. METHODS AND RESULTS: Patients with symptomatic drug-refractory AF, CHADS2 score of ≥1, and CHA2DS2-VASc score ≥2 were included. Catheter ablation consisted in pulmonary vein isolation with or without roof line with radiofrequency and LAA was occluded with the Watchman or Amplatzer Cardiac Plug (ACP) devices guided by angiography and transoesophageal echocardiography. A total of 35 patients were included (71% male; 70 years). Median score was 3 on both CHA2DS2-VASc and HAS-BLED, 9% had prior stroke under OAC, and 48% had bleeding complications. Successful CA and device implantation were achieved in 97% of cases. The Watchman device was used in 29 patients and ACP in 6 patients. Periprocedural complications included three cases of cardiac tamponade. At 3 months, all patients met the criteria for successful sealing of the LAA. After a mean follow-up of 13 months (3-75), 78% of patients were free of arrhythmia recurrences and OAC was withheld in 97% of patients. CONCLUSIONS: The combination of CA and percutaneous LAAC in a single procedure is technically feasible in patients with symptomatic drug-refractory AF, high risk of stroke, and contraindications to OACs, although it is associated with a significant risk of major complications.

Endocardial left ventricular lead placement from the left subclavian vein approach.

AIMS: In up to 10-15% of cases, the traditional epicardial approach for left ventricular (LV) lead placement is not feasible and surgical implantation is considered the alternative. We present the implantation of a transseptal LV lead through a left subclavian access. METHODS AND RESULTS: Through the left subclavian vein access and using a system which includes a guiding catheter, a puncture screw catheter and a puncture stylet, access to the LV was achieved and the LV stimulation lead was successfully implanted. CONCLUSION: We describe the implantation of a transseptal LV stimulation lead through a left subclavian access.

Reversal of spherical remodelling of the left atrium after pulmonary vein isolation: incidence and predictors.

AIMS: Pulmonary vein isolation (PVI) induces left atrial (LA) volume reduction, known as reverse remodelling (RR). The related changes in LA shape have not yet been evaluated. Left atrial sphericity (LASP) is a new shape-based marker of remodelling that compares LA geometry and a perfect sphere and is a powerful predictor of PVI success. We aimed to evaluate the effect of PVI on LASP and describe the concept of spherical and volumetric RR. METHODS AND RESULTS: Left atrial sphericity and volume were automatically obtained with self-customized software using a magnetic resonance imaging-based three-dimensional reconstruction of LA. Reverse remodelling was defined as improvement in LASP (spherical RR) or volume reduction (volumetric RR). In a series of 102 patients, spherical and volumetric RR was observed in 42.2 and 69%, respectively. Patients with paroxysmal atrial fibrillation (AF) had higher probability to present spherical RR as compared with patients with persistent AF (50.8 vs. 29.3%, P = 0.03). Patients with persistent AF showed significant post-procedural worsening of LASP (81.9 vs. 82.9%, P = 0.04). Patients with no recurrence showed a trend towards a higher proportion of spherical RR compared with those with recurrences (46.2 vs. 32.4%, respectively); no differences were observed in volumetric RR (62.1 vs. 62.9%, respectively). Paroxysmal AF was the only independent predictor of spherical RR. CONCLUSION: Pulmonary vein isolation leads to spherical RR in a substantial proportion of patients, and in higher proportion of patients with paroxysmal AF. Reverse remodelling may be caused by a combination of scarring and myocardial structural recovery. Changes in LASP might be more specific than volume reduction to detect favourable remodelling.

Transthoracic epicardial ablation of mitral isthmus for treatment of recurrent perimitral flutter.

BACKGROUND: Perimitral flutter (PMF) is a common form of left atrial tachycardia after atrial fibrillation (AF) ablation. The mitral isthmus (MI) is the standard ablation target. However, in some cases bidirectional block cannot be achieved. OBJECTIVE: The purpose of this study was to describe the first experience using a transthoracic epicardial (TTE) approach to treat recurrent PMF after prior unsuccessful ablation. METHODS: This is a case series of four patients with recurrence of highly symptomatic drug-refractory PMF (all male, median age 55 years, 3/4 hypertensive, 2/4 persistent AF, median AF period 24 months). Three patients presented with PMF-related tachymyocardiopathy. TTE ablation of MI was performed after a median of two prior endocardial MI and coronary sinus ablation attempts, using an open-tip 3.5-mm irrigated catheter (40 W, 45ºC). Persistent bidirectional block was assessed by activation mapping and differential pacing and was achieved in all patients. RESULTS: No PMF recurrence was observed after median follow-up of 18 months (range 15-22 months; two patients without antiarrhythmic drugs and two with previously ineffective amiodarone). Left ventricular function normalized in all three patients with tachycardiomyopathy. There were no complications related to TTE approach. CONCLUSION: The present study is the first to report the feasibility of a TTE approach for highly symptomatic PMF refractory to endocardial and coronary sinus MI ablation.

Impact of atrial fibrillation-induced tachycardiomyopathy in patients undergoing pulmonary vein isolation.

INTRODUCTION: Atrial fibrillation (AF) is a recognized treatable cause of tachycardiomyopathy (TMP), with class IIb indication for catheter ablation (CA). The aim of this study is to analyze the prevalence, clinical characteristics and effect of CA in patients with TMP and to evaluate TMP as a prognostic factor for AF recurrence in these patients (TMP group), compared to controls with normal left ventricular ejection fraction (LVEF) and patients with heart failure due to structural cardiomyopathy (HF group). METHODS AND RESULTS: The study groups included 659 consecutive patients undergoing CA between 2003 and 2011: TMP group (n = 61), HF group (n = 36) and control group (n = 562). Compared to controls, patients with TMP were younger, had a shorter AF course and more often had persistent AF. Regarding echocardiographic parameters, the TMP group had lower LVEF (40% vs. 62%, P < 0.05), larger left atrial diameter (LAD: 46 vs. 41 mm, P < 0.05) and LV end-diastolic diameter (LVEDD: 55 vs. 51 mm, P < 0.05) compared to controls, with significant improvement at six-month follow-up, including those patients with AF recurrence. The probability of being arrhythmia-free did not differ between the TMP group and the other groups after a first or last procedure. The only independent predictor of AF recurrence was LAD. CONCLUSIONS: Patients with tachycardiomyopathy secondary to AF benefit from CA, with a significant improvement in LVEF, LVEDD and LAD. The outcome after CA of this group did not differ from patients with no structural cardiomyopathy.

Left atrial sphericity: a new method to assess atrial remodeling. Impact on the outcome of atrial fibrillation ablation.

BACKGROUND: Atrial fibrillation (AF) ablation outcome is mainly determined by atrial remodeling that, nowadays, is only estimated through clinical presentation (persistent vs. paroxysmal) and left atrial (LA) dimension. The aim of the study was to stage the atrial remodeling process using the Left Atrial Sphericity (LASP) and determine whether this technique may help to predict AF ablation outcome. METHODS: Consecutive patients who underwent contrast-enhanced cardiac magnetic resonance angiography before AF ablation were included in the study. Three-dimensional reconstruction of LA excluding pulmonary veins and the LA appendage was used to define the LA cavity. The LASP was automatically obtained with self-customized software. RESULTS: 106 patients were included and categorized in 3 groups (Gs): discoid-LA (G1), intermediate-LA (G2), and spherical-LA (G3). The G3 patients had larger LA anteroposterior diameter than G1 and G2 patients (47 ± 7 vs 43 ± 6 and 39 ± 5 mm; P < 0.001), greater LA volume (90 ± 39 vs 86 ± 24 and 73 ± 20 mm; P = 0.012), and higher prevalence of persistent AF (75% vs 48% and 29%; P = 0.034) structural heart disease (75% vs 19% and 19%; P < 0.001), and AF recurrence at 12 months follow-up (58% vs 29% and 5%, P < 0.001). The LASP had linear correlation to predicted probability of recurrence. Multivariate analysis identified LASP (OR 1.320 [1.096-1.591], P = 0.004) and hypertension (OR 3.694 [1.282-10.645]; P = 0.016) as independent risk factors for arrhythmia recurrence. CONCLUSION: Left Atrial Sphericity is a new independent predictor of recurrence after AF ablation and may be useful in selecting the best candidates for AF ablation.

Radiofrequency catheter ablation of idiopathic right ventricular outflow tract arrhythmias.

Idiopathic ventricular arrhythmias (VA) consist of various subtypes of VA that occur in the absence of clinically apparent structural heart disease. Affected patients account for approximately 10% of all patients referred for evaluation of ventricular tachycardia (VT). Arrhythmias arising from the outflow tract (OT) are the most common subtype of idiopathic VA and more than 70-80% of idiopathic VTs or premature ventricular contractions (PVCs) originate from the right ventricular (RV) OT. Idiopathic OT arrhythmias are thought to be caused by adenosine-sensitive, cyclic adenosine monophosphate (cAMP) mediated triggered activity and, in general, manifest at a relatively early age. Usually they present as salvos of paroxysmal ventricular ectopic beats and are rarely life-threatening. When highly symptomatic and refractory to antiarrhythmic therapy or causative for ventricular dysfunction, ablation is a recommended treatment with a high success rate and a low risk of complications.

[Current status of cardiac resynchronization therapy]. / Estado actual de la terapia de resincronización cardiaca.

The present document reviews various aspects of the current status of cardiac resynchronization therapy: mechanisms of action, current indications and implantation technique.

Atrial fibrillation and atrial flutter in athletes.

Atrial fibrillation (AF) is the most common arrhythmia in clinical practice, with an estimated prevalence of 0.4% to 1% in the general population, increasing with age to 8% in those above 80 years. The recognised risk factors for developing AF include age, structural heart disease, hypertension, diabetes mellitus or hyperthyroidism. However, the mechanisms underlying the initiation of AF in patients below 60 years of age, in whom no cardiovascular disease or any other known causal factor is present, remain to be clarified. This condition, termed as lone AF, may be responsible for as many as 30% of patients with paroxysmal AF seeking medical attention. Recent studies suggest that long-term endurance exercise may increase the incidence of AF and atrial flutter (AFl) in this population. This review article is intended to analyse the prevalence of AF and AFl, the pathophysiological mechanisms responsible for the association between endurance sport practice and AF or AFl and the recommended therapeutic options in endurance athletes.