Silvia Montserrat

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

Abstract 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 ≥2000 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 ≥2000 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.

Left atrial size and function by three-dimensional echocardiography to predict arrhythmia recurrence after first and repeated ablation of atrial fibrillation

AIMS Left atrial (LA) size has been related to the success of radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF). However, potential predictors after a repeated procedure are unknown. We evaluate predictive factors related to successful AF ablation after a first and a repeated RFCA. METHODS AND RESULTS A total of 154 patients with AF were treated with RFCA. LA size and function were assessed with three-dimensional echocardiography (3D Echo) before RFCA. The effectiveness of RFCA was evaluated after 6 months. Recurrence of the arrhythmia was defined as any documented (clinically or by 24-h Holter recording) atrial tachyarrhythmia lasting >30 s after 12 weeks following RFCA. Of 154 patients, 103 (67%) underwent a first ablation (Group 1) and 51 (33%) a repeated RFCA (Group 2). At follow-up, arrhythmias were eliminated in 56 of 103 (54%) patients after a first RFCA and in 20 of 51 (40%) after a repeated ablation. In Group I, hypertension and LA expansion index derived from 3D Echo were independent predictors of arrhythmia elimination. In Group 2, only age predicted persistence of sinus rhythm; and only in younger patients (≤54 year old), though 3D LA maximal volumes were significantly smaller in those without when compared with those with AF recurrences. CONCLUSION A combination of the analysis of LA function with 3D Echo and clinical data predicts elimination of AF after a first ablation procedure for AF, beyond LA size. Among patients undergoing a repeated procedure, age and 3D echocardiographic LA maximum volume in younger patients predict the success of RFCA.

Usefulness of transoesophageal echocardiography before circumferential pulmonary vein ablation in patients with atrial fibrillation: is it really mandatory?

AIMS Transoesophageal echocardiography (TEE) is recommended prior to circumferential pulmonary vein ablation (CPVA) in patients with atrial fibrillation (AF) to identify left atrial (LA) or left atrial appendage (LAA) wall thrombi. It is not clear whether all patients undergoing CPVA should receive pre-procedural TEE. We wanted to assess the incidence of LA thrombus in these patients and to identify factors associated with its presence. METHODS AND RESULTS Consecutive patients referred for CPVA from 2004 to 2009 underwent TEE within 48 h prior to the procedure. Of 408 patients included in the study, 6 patients (1.47%) had LA thrombi, persistent AF, and LA dilation. Compared with patients without thrombus, these six patients had larger LA diameter (P = 0.0001) and more frequently were women (P = 0.002), had persistent AF (P = 0.04), and had underlying structural cardiac disease (P = 0.014). The likelihood of presenting LA thrombus increased with the number of these four risk factors present (P < 0.001). None of the patients with paroxysmal AF and without LA dilation had LA thrombus. A cut-off value of 48.5 mm LA diameter yielded 83% sensitivity, 92% specificity, and a 10.1 likelihood ratio to predict LA thrombus appearance. CONCLUSION The incidence of LA thrombus prior to CPVA is low. Persistent AF, female sex, structural cardiopathy, and LA dilation were associated with the presence of LA thrombus. Our data suggest that the use of TEE prior to CPVA to detect LA thrombi might not be needed in patients with paroxysmal AF and no LA dilation or structural cardiopathy.

Left atrial deformation predicts success of first and second percutaneous atrial fibrillation ablation.

BACKGROUND Predictors of second radiofrequency catheter ablation (RFCA) success are not well known. Surgical ablation is accepted for failed first RFCA, but second RFCA has fewer complications. OBJECTIVE The purpose of this study was to evaluate left atrial (LA) size and function as potential predictors of second RFCA for atrial fibrillation (AF). METHODS Thirty-three healthy volunteers (group I) and 83 patients with symptomatic drug-refractory AF treated with a first RFCA (group II, n = 48) or a second RFCA (group III, n = 35 patients) were included. Echocardiography was performed in all patients in sinus rhythm before RFCA and in all volunteers. LA size and function were measured using longitudinal strain and strain rate during ventricular systole (LASs, LASRs) and during early diastole (LASRe) or late diastole (LASRa) with speckle tracking echocardiography. The effectiveness of RFCA on arrhythmia recurrence was evaluated at 6-month follow-up. RESULTS LASs, LASRs, and LASRa were significantly lower in group III patients compared to other groups (P < .001 for all). LA diameter or volumes did not predict success after RFCA. LASs was an independent predictor of arrhythmia suppression after a first RFCA and after a second RFCA, with the best cutoff at LASs >20% (sensitivity 86%, specificity 70%) and LASs >12% (sensitivity 84%, specificity 90%), respectively. CONCLUSION LA myocardial deformation imaging is a reliable tool for predicting success after a first and a second RFCA. These parameters could improve candidate selection, especially for a second RFCA.

Usefulness of Echocardiography in Preparticipation Screening of Competitive Athletes

INTRODUCTION AND OBJECTIVES Despite the established diagnostic value of the electrocardiogram in preparticipation screening of athletes, some cardiac structural changes can be missed, particularly in early disease stages. The aim of this study was to evaluate the prevalence of cardiac structural changes via the systematic use of echocardiography in preparticipation screening of competitive athletes. METHODS Professional athletes or participants in a competitive athletic program underwent a screening that included family and personal medical history, physical examination, electrocardiography, exercise testing, and Doppler echocardiography. RESULTS A total of 2688 athletes (67% men; mean age [standard deviation], 21 [10] years) were included. Most of the echocardiographic evaluations (92.5%) were normal and only 203 (7.5%) showed changes; the most frequent change was left ventricular hypertrophy, seen in 50 athletes (1.8%). Cessation of athletic activity was indicated in 4 athletes (0.14%): 2 for hypertrophic cardiomyopathy (electrocardiography had shown changes that did not meet diagnostic criteria), 1 pectus excavatum with compression of the right ventricle, and 1 significant pulmonary valve stenosis; the rest of the changes did not entail cessation of athletic activity and only indicated periodic monitoring. CONCLUSIONS Although rare, some cardiac structural changes can be missed on physical examination and electrocardiography; in contrast, they are easily recognized with echocardiography. These findings suggest the use of echocardiography in at least the first preparticipation screening of competitive athletes to improve the effectiveness of programs aimed at preventing sudden death in athletes.

Effect of repeated radiofrequency catheter ablation on left atrial function for the treatment of atrial fibrillation.

Radiofrequency catheter ablation (RFCA) is a potential curative treatment for atrial fibrillation (AF) by eliminating the arrhythmia and inducing left atrial (LA) reverse remodeling. However, the effect on LA function, especially after repeated procedures, has scarcely been studied. The aim of this study was to evaluate the impact of RFCA on LA size and function in patients with AF after a first and a repeated procedure. RFCA was performed in 154 patients with symptomatic drug-refractory AF. LA volumes and function were assessed with real-time 3-dimensional echocardiography before and 6 months after the procedure. Recurrence of the arrhythmia was defined as any atrial tachyarrhythmia lasting >30 seconds, clinically documented or by 24-hour Holter recording, after the first 6 months after ablation. Of the 154 patients, 104 (67%) required only a first ablation, and 50 (33%) required redo RFCA. LA volume was reduced after first RFCA (from 60 ± 19 to 52 ± 17 ml for 3-dimensional LA maximum volume, p <0.001, and from 38 ± 18 to 33 ± 15 ml for 3-dimensional LA minimum volume, p <0.000) without impairment of LA contractile function, measured as the active emptying percentage of total volume (39 ± 25% vs 43 ± 26%, p = NS). After repeated RFCA procedures, 3-dimensional LA maximum volume was reduced (from 57 ± 18 to 52 ± 18 ml, p = 0.04), also without further LA contractile function impairment (active emptying percentage of total volume) (36 ± 24% vs 36 ± 25% of total volume, p = NS). This effect was similar in paroxysmal and persistent AF. In conclusion, RFCA induces reductions in LA volumes without a deleterious impact on contractile function, even after repeated ablation.

Gender influence on the adaptation of atrial performance to training

Abstract Background: High-intensity training has been associated with atrial remodelling and arrhythmias in men. Our purpose was to analyse atrial performance in female endurance athletes, compared to male athletes and controls. Methods: This was a cross-sectional study. We included four groups: female athletes, females controls, male athletes and male controls. Left (LA) and right atrial (RA) volumes and function were assessed using 2D and speckle-tracking echocardiography to determine peak atrial strain-rate at atrial (SRa) and ventricular contraction (SRs), as surrogates of atrial contractile and reservoir function, respectively. ANOVA and Bonferroni’s statistical tests were used to compare variables among groups. Results: We included 82 subjects, 39 women (19 endurance athletes, 20 controls) and 43 men (22 endurance athletes, 21 controls). Mean age was similar between groups (36.6 ± 5.6 years). Athletes had larger bi-atrial volumes, compared to controls (women, LA 27.1 vs. 15.8 ml/m2, p < 0.001; RA 22.31 vs. 14.2 ml/m2, p = 0.009; men, LA: 25.0 vs. 18.5 ml/m2, p = 0.003; RA 30.8 vs. 21.9 ml/m2, p < 0.001) and lower strain-rate (women, LASRa −1.60 vs. −2.18 s−1, p < 0.001; RASRa −1.89 vs. −2.38 s−1, p = 0.009; men, LASRa −1.21 vs. −1.44 s−1, p = 1; RASRa −1.44 vs. −1.60 s−1, p = 1). However, RA indexed size was lower and bi-atrial deformation greater in female athletes, compared to male athletes. Conclusions: The atria of both male and female athletes shows specific remodelling, compared to sedentary subjects, with larger size and less deformation at rest, particularly for the RA. Despite a similar extent of remodelling, the pattern in women had greater bi-atrial myocardial deformation and smaller RA size.

Prevention of sudden death in adolescent athletes: Incremental diagnostic value and cost-effectiveness of diagnostic tests

Introduction Pre-participation screening in athletes attempts to reduce the incidence of sudden death during sports by identifying susceptible individuals. The objective of this study was to evaluate the diagnostic capacity of the different pre-participation screening points in adolescent athletes and the cost effectiveness of the programme. Methods Athletes were studied between 12–18 years old. Pre-participation screening included the American Heart Association questionnaire, electrocardiogram, echocardiogram, and stress test. The cost of test was established by the Catalan public health system. Results Of 1650 athletes included, 57% were men and mean age was 15.09 ± 1.82 years. Positive findings were identified as follows: in American Heart Association questionnaire 5.09% of subjects, in electrocardiogram 3.78%, in echocardiogram 4.96%, and in exercise test 1.75%. Six athletes (0.36%) were disqualified from participation and 10 (0.60%) were referred for interventional treatment. Diagnostic capacity was assessed by the area under the curve for detection of diseases that motivated disqualification for sport practice (American Heart Association questionnaire, 0.55; electrocardiogram, 0.72; echocardiogram, 0.88; stress test, 0.57). The cost for each athlete disqualified from the sport for a disease causing sudden death was €45,578. Conclusion The electrocardiogram and echocardiogram were the most useful studies to detect athletes susceptible to sudden death, and the stress test best diagnosed arrhythmias with specific treatment. In our country, pre-participatory screening was cost effective to detect athletes who might experience sudden death in sports.

Characterizing the spectrum of right ventricular remodelling in response to chronic training

The significance and spectrum of reduced right ventricular (RV) deformation, reported in endurance athletes, is unclear. To comprehensively analyze the cardiac performance at rest of athletes, especially focusing on integrating RV size and deformation to unravel the underlying triggers of this ventricular remodelling. Hundred professional male athletes and 50 sedentary healthy males of similar age were prospectively studied. Conventional echocardiographic parameters of all four chambers were obtained, as well as 2D echo-derived strain (2DSE) in the left (LV) and in the RV free wall with separate additional analysis of the RV basal and apical segments. Left and right-sided dimensions were larger in athletes than in controls, but with a disproportionate RA enlargement. RV global strain was lower in sportsmen (−26.8 ± 2.8% vs −28.5 ± 3.4%, p < 0.001) due to a decrease in the basal segment (−22.8 ± 3.5% vs −25.8 ± 4.0%, p < 0.001) resulting in a marked gradient of deformation from the RV inlet towards the apex. By integrating size, deformation and stroke volume, we observed that the LV working conditions were similar in all sportsmen while a wider variability existed in the RV. Cardiac remodelling in athletes is more pronounced in the right heart cavities with specific regional differences within the right ventricle, but with a wide variability among individuals. The large inter-individual differences, as well as its acute and chronic relevance warrant further investigation.

Left Atrial Function Is Impaired in Some Patients With Stroke of Undetermined Etiology: Potential Implications for Evaluation and Therapy

INTRODUCTION AND OBJECTIVES Stroke etiology remains undetermined in up to 30% of cases. Paroxysmal atrial fibrillation is found in 20% to 28% of patients with stroke initially classified as being of undetermined etiology. The aim of our study was to analyze left atrial function in ischemic stroke patients to identify patterns associated with cardioembolic etiology and to determine whether the patterns identified can be found in individuals initially classified as having a stroke of undetermined etiology. METHODS We studied a cohort of in-hospital ischemic stroke patients referred for transthoracic echocardiography. Treating neurologists determined stroke etiology based on the TOAST classification. Left atrial contractile function was assessed using 2-dimensional echocardiography to determine their ejection fraction and speckle tracking to measure left atrial strain rate: a-wave. Left atrial function was compared between stroke etiology subgroups and healthy controls. RESULTS Ninety-seven patients (aged 67±15 years) with ischemic stroke (16.5% large-artery atherosclerosis, 15.5% small-vessel occlusion, 11.3% cardioembolic, 5.1% other determined etiology, 51.1% undetermined etiology) and 10 healthy volunteers (aged 63±7 years) were included. Left atrial ejection fraction was significantly decreased only in patients with stroke of cardioembolic and undetermined etiology compared with the control group (31.5±17.2%, 40.2±17.1%, and 59.1±8.4%, respectively; P=.004). The left atrial strain rate was significantly lower in patients with stroke caused by cardioembolic or undetermined etiology, or large-artery atherosclerosis compared with controls (-0.86±0.49, -1.31±0.56, -1.5±0.47, -2.37±1.18, respectively; P<.001). CONCLUSIONS Patients with stroke of undetermined etiology with left atrial function (ejection fraction and strain) similar to that of cardioembolic stroke patients may be misclassified and could potentially benefit from prolonged electrocardiography monitoring. Left atrial function analysis (ejection fraction and strain) might help to identify potential cardioembolic sources in patients with stroke of undetermined etiology.