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Cardiorespiratory fitness (CRF) has been shown to correlate with incident atrial fibrillation (AF) and AF burden. In recent years there has been increasing recognition of the pivotal role of modifying risk factors before AF ablation.The purpose of this study was to investigate whether higher baseline CRF measured using exercise stress testing (EST) was associated with improved outcomes after AF ablation.We studied 591 patients who underwent EST within 12 months before AF ablation. Patients were categorized into low (85% predicted), adequate (85%-100% predicted), and high (100% predicted) CRF groups. Outcomes of interest included arrhythmia recurrence, cessation of antiarrhythmic therapy, repeat hospitalization for arrhythmia, repeat rhythm control procedures, and all-cause mortality.During mean follow-up of 32 months after ablation, arrhythmia recurrence was observed in 79% of patients in the low CRF group compared to 54% in the adequate CRF group and 27.5% in the high CRF group (P.0001). Similarly, rates of repeat arrhythmia-related hospitalization, repeat rhythm control procedures, and need for ongoing antiarrhythmic therapy were significantly lower in the high CRF group (P.0001). Death occurred in 2.5% of patients in the high CRF group compared to 4% in the adequate CRF group and 11% in the low CRF group (P.0001). In Cox proportional hazards analyses, high CRF was significantly associated with lower arrhythmia recurrence.Higher CRF is associated with reduced arrhythmia recurrence rates and death among patients undergoing AF ablation. Efforts should be made to enhance CRF before AF ablation.

Left atrial (LA) size and low-voltage areas (LVA) mirror atrial fibrillation (AF) progression. Whether these factors are important for the impairment of total atrial emptying fraction is understudied.The aim of the present analysis was to investigate the association between LA volume and total atrial emptying fraction with AF progression phenotypes: persistent AF and LVA.Patients undergoing first AF ablation were included in the analysis. LVA were determined using high-density maps and defined as0.5 mV. All patients underwent cardiovascular magnetic resonance imaging before the intervention. Cardiovascular magnetic resonance data (LA volume, LA emptying fraction [LA-EF], and right atrial emptying fraction [RA-EF]) were measured in all patients.The study population included 211 patients (65 ± 11 years; 124 (59%) men; 122 (58%) persistent AF; 54 (26%) LVA). There were 4 disease progression groups: paroxysmal AF without LVA, paroxysmal AF with LVA, persistent AF without LVA, and persistent AF with LVA. While LA volume increased according to the AF progression phenotype (98 ± 27, 145 ± 34, 134 ± 41, 141 ± 39 mL, respectively; P.001), total LA-EF (51% ± 17%, 32% ± 17%, 33% ± 17%, 22% ± 11%; P .001) and RA-EF (47% ± 13%, 36% ± 17%, 30% ± 16%, 23% ± 12%; P.001) decreased. In multivariable analysis, age (odds ratio [OR] 1.084; 95% confidence interval [CI] 1.028-1.142; P = .003), persistent AF (OR 3.478; 95% CI 1.117-10.830; P = .031), and total LA-EF (OR 0.933; 95% CI 0.899-0.968; P.001) showed a significant association for LVA. Using receiver operating characteristic curve analysis, LA-EF (area under the curve 0.778; 95% CI 0.711-0.846; P.001) and RA-EF (area under the curve 0.726; 95% CI 0.650-0.802; P .001) were significantly associated with the absence of LVA.LVA and persistent AF are associated with worse total atrial emptying fraction.

Background Anatomic studies have reported the presence of shared myocardial fibers between approximately half of ipsilateral pulmonary veins (IPVs). Objective The purpose of this study was to assess the prevalence of electrical connection between IPVs and the impact of antral isolation with or without carina ablation on IPV connection. Methods Thirty consecutive patients undergoing atrial fibrillation (AF) ablation (14 redo) were included. Wide antral pulmonary vein isolation (PVI) was performed with or without carina lesions. For each PV set, IPV electrical connection was assessed before and after PVI by pacing and recording from the ostium of both IPVs using a circular mapping catheter and the ablation catheter. Adenosine was given after PVI to assess for acute PV reconnection. Results Before PVI without preceding AF ablation procedure, all the PVs had ipsilateral connection albeit frequently via the left atrium. After PVI, 65.6% of the IPVs were connected without carina ablation vs 17.7% if prior carina ablation (P = .001). Left vs right IPVs were connected in 57.1% and 72.2% of the cases without carina ablation, respectively, vs 30% and 0% of cases with carina ablation (P = .19 and P = .001). When transient PV reconnection was demonstrated during adenosine challenge, connected IPVs uniformly demonstrated simultaneous reconnection. Conclusion Electrical connection between IPVs is uniformly demonstrated before any ablation. Two-thirds of the IPVs are connected after antral PVI, and carina ablation decreases IPV connection. Connected IPVs consistently show the same response to adenosine challenge; therefore, a single catheter positioned in either of the IPVs with electrical connection is sufficient to confirm reconnection in both veins.

Background There is an association between obesity and atrial fibrillation (AF). The impact of obesity on AF ablation procedures is unclear. Objective The purpose of this study was to evaluate the influence of body mass index (BMI) on patient characteristics, long-term ablation outcomes, and procedural complications. Methods We evaluated 2715 patients undergoing 3742 AF ablation procedures. BMI was ≥30 kg/m2 in 1058 (39%) and ≥40 kg/m2 in 129 (4.8%). Patients were grouped by BMI ranges ( Results As BMI increased from Conclusion In patients undergoing AF ablation, increasing BMI is associated with more patient comorbidities and more persistent and long-standing AF. BMI ≥35 kg/m2 adversely impacts ablation outcomes, and BMI ≥40 kg/m2 increases minor complications.

w i D h C C Ablative procedures to cure atrial fibrillation (AF) have gained popularity worldwide and prompted the development of new, complex, and expensive tools to achieve a high level of success (new energy sources, ablation tools, sophisticated mapping systems, etc). Despite the initial reports of very high procedural success, later revelations from a number of high-volume centers have postulated a more modest efficacy that decreases further with higher complexity and chronicity of AF substrate. Long-term maintenance of sinus rhythm has also been called into question recently. The unbiased analysis of these varying results is further complicated by the fact that they were obtained with a number of different ablation approaches, all stemming from the fact that our understanding of AF mechanism is far from agreed upon. Focal AF source theory initially was introduced by Sir Thomas Lewis in 1925 and later was replaced by the multiple wavelet hypothesis of Moe and Abildskov in 959. More recently, pioneering work by Haissaguerre et l has again called attention to arrhythmogenic foci inside he pulmonary veins. Thus, the old focal source AF theory as again revived. However, subsequent suboptimal clinial results with pulmonary vein isolation, particularly in atients with persistent AF, have again called into question he theory of underlying AF mechanisms, prompting the evival of the multiple wavelet hypothesis at a new level. his time, meandering wavefronts, mother rotors, and reakthrough waves are suggested to explain the perpetuaion of AF. Observation of complex fractionated atrial elecrograms (CFAEs) and dominant frequencies (DFs) seemed o fit the changing hypothesis and provide the sought-after linical result of cure. It also has brought forward further technological development to “check the harmony by algebra” and automate and standardize the definitions of these complex phenomena. Unfortunately, subsequent exploration of the subject brought a wide variety of conflicting data in both time and frequency domain.