Aims To assess left atrial (LA) function in sinus rhythm in veteran athletes with a history of paroxysmal atrial fibrillation (AF) exposed to prolonged endurance exercise compared with veteran athletes without AF and controls with and without paroxysmal AF from a non-athletic population. Methods and results Three hundred and two male participants from four groups, veteran recreational skiers with paroxysmal AF (n = 62), veteran skiers without AF (n = 89), and controls from a non-athletic population with (n = 62) and without paroxysmal AF (n = 89) underwent an echocardiographic examination in sinus rhythm to evaluate LA anatomy and function. The skiers (mean age 70.8±6.7 years) reported an average exposure to regular endurance exercise for 40–50 years. LA maximum and minimum volumes were larger in skiers (P < 0.001). LA volumes differed within the athletic and non-athletic groups with larger volumes in the AF groups ( P < 0.001). We observed a considerable overlap in LA volumes among non-athletes with AF and athletes without AF. LA reservoir strain (33.6% ± 4.8% vs. 28.3% ± 6.7% P < 0.001) and contractile strain (18.3% ± 4.0% vs. 15.0% ± 5.2% P < 0.001) were lower in both AF groups regardless of athletic status. LA reservoir strain was superior to volumetric measurements at identifying participants with AF (area under the curve 0.740 ±0.041). Conclusion Male veteran athletes had significantly larger LA volumes than non-athletes. In contrast, LA strain values were similar in athletes and non-athletes with paroxysmal AF, and significantly lower than in subjects without AF.

Aims The current study aimed to describe normal values of left atrial (LA) volumes and LA emptying fraction (LAEF) in a large sample in their mid-60s from the general population and to explore sex differences. Methods and results In the Akershus Cardiac Examination (ACE) 1950 Study, body surface area-indexed LA maximum (LAVimax) and minimum (LAVimin) volumes and LAEF were measured in 3489 individuals aged 63.9 ± 0.6 years from the general population. A healthy group of 832 individuals was defined. Data are presented as mean ± standard deviation (SD) and a normal range of mean ± 2 SD. T-tests were used for comparisons. In the healthy group, mean LAVimax was 25.5 ± 6.2 mL/m2 and the normal range was 13.1–37.9 mL/m2. Men had significantly larger body surface area-indexed volumes than women, but there was no difference in LAEF. The mean LAVimax for healthy men was 26.4 ± 6.5 mL/m2, for healthy women 24.9 ± 5.8 mL/m2 (P < 0.001) and the upper normal limits were 39.4 and 36.5 mL/m2, respectively. In the healthy group, 13.0% of all men and 5.4% of all women had LAVimax above the current upper normal limit of 34 mL/m2. Conclusion A large proportion of healthy individuals, in particular men, had LAVimax >34 mL/m2. Our findings suggest that the recommended cut-off may be too low at the age of 65 years and above and that sex-specific cut-offs should be considered.

ObjectiveAtrial fibrillation is a common arrhythmia associated with risk of stroke, heart failure and death. We aimed to elucidate the associations of cardiac biomarkers, echocardiographic left atrial volumetric indices and risk of prevalent and incident atrial fibrillation in the general population.MethodsWe assessed cardiac troponin T (cTnT), N-terminal pro-B-type natriuretic peptide (NT-proBNP), growth differentiation factor 15 (GDF-15), maximum (LAVimax) and minimum (LAVimin) indexed left atrial volumes and left atrial emptying fraction (LAEF) in subjects born in 1950 participating in the prospective observational cohort, Akershus Cardiac Examination 1950 Study. The Cohorts for Heart and Ageing Research in Genomic Epidemiology for Atrial Fibrillation risk score and sex was used to adjust for residual risk of atrial fibrillation.ResultsOut of 3487 subjects, 157 (4.5%) had prevalent and 123 (3.5%) had incident atrial fibrillation. Echocardiographic left atrial volumes and cardiac biomarkers associated with prevalent atrial fibrillation, but GDF-15 was non-significant in adjusted analysis. Incident atrial fibrillation was predicted by LAVimax(adjusted HR 1.51, 95% CI 1.30 to 1.75), LAVimin(adjusted HR 1.52, 95% CI 1.35 to 1.72), LAEF (adjusted HR 1.24, 95% CI 1.04 to 1.48) and NT-proBNP (adjusted HR 1.57, 95% CI 1.32 to 1.85). cTnT and NT-proBNP provided incremental prognostic information to left atrial volumes, but GDF-15 demonstrated no prognostic value for incident atrial fibrillation.ConclusionsIn the general population, echocardiographic left atrial volumetric indices and NT-proBNP, but not cTnT and GDF-15, associate with prevalent atrial fibrillation and with risk of incident atrial fibrillation. cTnT and NT-proBNP provide incremental prognostic information to echocardiography.

Aims Left atrial (LA) strain is promising in prediction of clinical atrial fibrillation (AF) in stroke patients. However, prediction of subclinical AF is critical in patients with embolic strokes of undetermined source (ESUS). The aim of this prospective study was to investigate novel LA and left atrial appendage (LAA) strain markers in prediction of subclinical AF in ESUS patients. Methods and results A total of 185 patients with ESUS, mean age 68 ± 13years, 33% female, without diagnosed AF, were included. LAA and LA function by conventional echocardiographic parameters and reservoir strain (Sr), conduit strain (Scd), contraction strain (Sct), and mechanical dispersion (MD) of Sr were assessed with transoesophageal and transthoracic echocardiography. Subclinical AF was detected by insertable cardiac monitors during follow-up. LAA strain was impaired in 60 (32%) patients with subclinical AF compared to those with sinus rhythm: LAA-Sr, 19.2 ± 4.5% vs. 25.6 ± 6.5% (P < 0.001); LAA-Scd, −11.0 ± 3.1% vs. −14.4 ± 4.5% (P < 0.001); and LAA-Sct, −7.9 ± 4.0% vs. −11.2 ± 4% (P < 0.001), respectively, while LAA-MD was increased, 34 ± 24 ms vs. 26 ± 20 ms (P = 0.02). However, there was no significant difference in phasic LA strain or LA-MD. By ROC analyses, LAA-Sr was highly significant in prediction of subclinical AF and showed the best AUC of 0.80 (95% CI 0.73–0.87) with a sensitivity of 80% and a specificity of 73% (P < 0.001). LAA-Sr and LAA-MD were both independent and incremental markers of subclinical AF in ESUS patients. Conclusion LAA function by strain and mechanical dispersion predicted subclinical AF in ESUS patients. These novel echocardiographic markers may improve risk stratification in ESUS patients.

Funding Acknowledgements Type of funding sources: Public hospital(s). Main funding source(s): Akerhus University Hospital Dept. of Cardiology Background Cryptogenic stroke/TIA (CS) is supposed to be associated with intracardiac thrombus formation and left atrial (LA) structure, in particular thrombus formation in left atrial appendage (LAA). However, there is little evidence if thromboembolic risk is associated with LAA morphology in patients with CS. Purpose We aimed to investigate, if different LAA morphology types may predict thromboembolic risk in patients with CS. Methods In this prospective study (mean follow-up 859 ± 226 days), 185 patients with CS (mean age 68 ±13 years, 33% female) without history of AF were included. All patients underwent complete transesophageal echocardiography in sinus rhythm after index CS (mean 5 ± 3days). Occurrence of LAA thrombus, sludge or spontaneous echo contrast (SEC) were defined as thromboembolic risk and LAA structure was evaluated by 2D and 3D transesophageal echocardiography. Multilobate LAA was defined as LAA with  > 1 lobes. Results Of the 185 included patients, LAA type chicken wing was found in 79 (43%), type windsock in 64 (35%), type cactus in 35 (19%) and type cauliflower in 7 (4%). Thrombus formation occurred in 29/185 (16%), LAA sludge in 112/185 (61%), and LAA SEC in 74/185 (40%), which is increased compared to data in the general population. We found SEC in sludge in 65/112 (58%), SEC in thrombus in 18/29 (62%) and sludge in thrombus in 27/29 (93%). SEC and sludge were significantly associated with thrombus formation, (p < 0.001 and p < 0.01, respectively). Finally, thromboembolic risk occurred in 123 (67%) of all patients with CS. Moreover, LAA type chicken wing was significantly associated with thromboembolic risk (p < 0.01), while all other LAA types were not. Multilobate LAA occurred in 115 (62%) of all patients and predicted thromboembolic risk vs. non-lobated LAA (p= 0.04). In a multivariate analysis LAA type chicken wing and multilobate LAA were independently predictors of thromboembolic risk, figure 1. Conclusions Patients with cryptogenic stroke/TIA without history of AF showed increased thromboembolic risk, and SEC and sludge were significantly associated with LAA thrombus formation. Only LAA type chicken wing and multilobate LAA predicted independently thromboembolic risk in this study. Abstract Figure.

Background Left atrial (LA) strain measurements by speckle tracking echocardiography (STE) are predictive markers of cardiovascular morbidity, including atrial fibrillation (AF). LA mechanical dispersion (LA MD) is a new parameter derived from STE. A reduction of LA strain is considered to reflect LA dysfunction, while increased LA MD may reflect LA dyssynchrony. Purpose To assess LA dysfunction and dyssynchrony, as measured by STE, in patients with paroxysmal AF (pAF). Methods A subset of 616 participants in the Akershus Cardiac Examination 1950 Study were divided into three groups: (1) A healthy group (n=179) defined by excluding AF, coronary artery disease, stroke, hypertension, chronic obstructive pulmonary disease, body mass index >30, left ventricular ejection fraction <50%, transmitral E/e' >14 or E/A >2.0, (2) A non-healthy group (n=350) of participants without pAF, but with any of the above conditions, (3) A group with pAF, but in sinus rhythm at examination (n=87). LA reservoir strain (LASr), conduit strain (LAScd) and contractile strain (LASct), as well as LA MD were assessed by STE. MD was defined as the standard deviation (SD) of time from ECG R to peak atrial longitudinal strain (SD-TPS), and corrected by RR-interval (SD-TPS/RR), expressing LA MD as a percentage of the cardiac cycle. Comparisons were made by Mann-Whitney U-test due to non-normal distributions. Results Mean age was 63.5±0.5 years and 46.6% were women. LASr, LAScd and LASct were significantly lower, and LA MD significantly higher in the pAF group compared to the healthy and non-healthy groups (Table; Figure). Conclusion The present study has demonstrated LA dysfunction and dyssynchrony in patients with pAF, which may reflect LA remodeling and increased fibrosis. Figure 1 Funding Acknowledgement Type of funding source: Public Institution(s). Main funding source(s): South-Eastern Norway Regional Health Authority

Background Even though physical activity is inversely associated with cardiovascular disease, long-term endurance exercise increases the risk of AF in middle-aged and older men, and has been linked to cardiac structural changes mimicking arrhythmogenic cardiomyopathy on susceptible individuals. Healthy younger athletes adapt to the increased demands of exercise with symmetric enlargement of the cardiac chambers with preserved functional properties. Data describing cardiac structure and function in older veteran athletes after decades of performing endurance exercise are scarce and add essential information when wanting to discern physiological from pathological remodeling in this group. Purpose To investigate cardiac structural and functional remodeling in relation to long-term endurance exercise in veteran athletes. Methods To cover the entire range of physical activity in the population, the study comprised two independent cohorts; Veteran male athletes who had participated in the annual 54 km Birkebeiner cross-country ski race and men who had participated in a population-based health survey. Individuals with a history of cardiac arrhythmias were excluded. Regular endurance exercise was defined as exercise for ≥30 minutes at least three times weekly with the purpose of increasing physical endurance capacity and self-reported as categories of years of regular endurance exercise. All participants underwent a resting echocardiographic examination. A One-way ANOVA with polynomial contrasts was conducted to explore the effect of years of endurance exercise on cardiac size and function. Results 178 men with a mean age of 70.9±6.5 years were included in the study, 89 veteran athletes, who had practiced regular endurance exercise for an average of 40–50 years, and completed an average of 19 annual Birkebeiner ski races and 89 individuals from the general population. Fifty-seven had never performed regular endurance exercise, 29 1–20 years of exercise, 25 20–40 years of exercise, and 67 >40 years of endurance exercise. Left atrial, left ventricular, right atrial, and right ventricular dimensions increased with cumulative years of exercise (p<0.001), while function remained similar in all cardiac chambers. Conclusion Atrial and ventricular dimensions increased with cumulative years of endurance exercise. Atrial and ventricular function assessed by strain, however, seemed to be unaffected by long-term exposure to exercise. These results suggest recreational endurance athletes preserve normal cardiac function despite athletic remodeling. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): A Ph.D. grant from the DAM foundationA grant from the Raagholt foundation

Background: Prolonged endurance exercise is associated with an increased risk of atrial fibrillation (AF) in men. Left atrial (LA) dilation is a marker of pathological atrial remodeling and associated with AF in the general population. In athletes, however, atrial dilation is part of a physiological response to exercise, and functional parameters may help separate physiological from pathological atrial remodeling in this group. LA mechanical dispersion (LA MD) is a novel marker of LA mechanical dyssynchrony associated with AF in the general population. The associations between prolonged endurance exercise, LA MD and AF are yet to be investigated. Purpose: To investigate LA MD in male veteran athletes who had regularly participated in an annual 54-kilometer cross-country (XC) ski race in Norway with and without paroxysmal AF and to investigate the ability of LA MD to identify veteran athletes with paroxysmal AF. Methods: Two hundred and ninety-three men from four groups, veteran XC skiers with (n=57) and without (n=87) AF, and men from a non-athletic population with (n=61) and without AF (n=88) underwent an echocardiographic exam while in sinus rhythm. Using speckle-tracking echocardiography, LA strain was measured in each of the six atrial segments in an atrial-focused apical four-chamber view. We defined LA MD as the standard deviation of time-to-peak strain (SD-TPS) and report the average from three consecutive loops. Results: XC-skiers (mean age 70.9 ± 5.7 years) reported an average of 40-50 years of regular endurance exercise and an average of 16 completed annual Birkebeiner XC ski races. LA volumes were associated with both AF and athletic status (p<0.001). SD-TPS was associated with AF (p<0.001), but not with athletic status (p=0.173). We found no significant trend between years of endurance exercise and SD-TPS in individuals without AF (p=0.846). SD-TPS did not add incremental value in identifying athletes with AF in addition to clinical markers, QRS width, LA volume, and LA reservoir strain (p=0.056). Conclusion: LA MD was associated with paroxysmal AF regardless of athletic status. However, it was not associated with years of performing endurance exercise, suggesting LA MD could be a promising marker of pathological atrial remodeling in endurance athletes, less affected by physiological exercise-induced atrial remodeling than absolute volumetric measurements. We found no incremental value of LA MD in identifying veteran athletes with paroxysmal AF when LA reservoir strain was included in the model.