Left Atrial Area Research Articles

Ethnic and sex-related differences at presentation in apical hypertrophic cardiomyopathy: An observational cross-sectional study

BackgroundWe investigated whether ethnicity and sex are associated with different clinical presentations and cardiovascular magnetic resonance (CMR) findings in individuals with apical hypertrophic cardiomyopathy (ApHCM). MethodsA retrospective observational cohort study of consecutive ApHCM patients from a large tertiary referral center in the United Kingdom (UK). Demographic, clinical, 12‑lead electrocardiogram (ECG) and CMR findings were collected. Participants presented in our clinics between 2010 and 2020. ‘Pure’ ApHCM was defined as isolated apical hypertrophy and ‘mixed’ with both apical and septal hypertrophy but with the apical segments of a greater wall thickness. Deep T-wave inversion was defined as ≥5 mm in any electrocardiogram lead. ResultsA total of 150 consecutive ApHCM patients (75% men, 25% women; 37% White, 25% Black, 24% Asian and 15% of Mixed/Other ethnicity) were included. Females were diagnosed at an older age compared to men, had less prominent ECG changes, had higher left atrial area index, and were more hypertensive. Black patients had higher left ventricular mass index, more hypertension, and more of the ‘mixed’ type of ApHCM. The majority of hypertensive male patients showed the ‘mixed’ phenotype. ConclusionsIndividuals of Black ethnicity and hypertensive male patients are more likely to present with mixed apical and basal hypertrophy, whereas White, Asian and non-hypertensive male patients tend to have hypertrophy limited to the apex. Females present at an older age and are less likely to have deep T wave inversion on ECG.

Impact of Device Implant Depth After Left Atrial Appendage Occlusion

BackgroundDevice-related thrombus (DRT) remains one of the main concerns after left atrial appendage occlusion (LAAO). Several risk factors have been proposed, but most cannot be modulated. A modifiable factor such as device implantation depth is a potential target to adjust the risk for DRT. ObjectivesThe aim of this study was to assess the impact of LAAO device implantation depth as a predisposing factor for DRT. MethodsThe study included patients who underwent successful LAAO at 9 centers in Europe and Canada. Patients were classified into 2 groups: proximal device implantation (covered pulmonary ridge [PR] in the lobe and disc cohort or <5 mm from the PR in the single-lobe cohort) and distal device implantation (uncovered PR in the disc and lobe cohort and ≥5 mm in the single-lobe cohort). ResultsA total of 1,317 patients were included. Among these, proximal and distal device implantation was achieved in 732 (55%) and 585 (45%) patients, respectively. No differences in procedural outcomes were observed between the groups. At follow-up, patients with proximal implantation had a lower incidence of DRT (2.3%) than those with distal implantation (12.2%) (P < 0.001). Deeper device implantation and a larger uncovered left atrial appendage area were associated with a higher incidence of DRT (P < 0.001), regardless of device type. In multivariable analysis, distal implant (HR: 5.92; 95% CI: 3.39-10.36) and no or single antiplatelet therapy (HR: 1.62; 95% CI: 0.99-2.62) emerged as independent predictors of DRT. ConclusionsLAAO device implantation depth is an independent risk factor for DRT. Deeper device implantation and larger uncovered left atrial appendage areas were associated with a higher incidence of DRT.

Baseline Intraoperative Left Ventricular Diastolic Function Is Associated with Postoperative Atrial Fibrillation after Cardiac Surgery.

Detailed understanding of the association between intraoperative left atrial and left ventricular diastolic function and postoperative atrial fibrillation is lacking. In this post hoc analysis of the Posterior Left Pericardiotomy for the Prevention of Atrial Fibrillation after Cardiac Surgery (PALACS) trial, we aimed to evaluate the association of intraoperative left atrial and left ventricular diastolic function as assessed by transesophageal echocardiography (TEE) with postoperative atrial fibrillation. PALACS patients with available intraoperative TEE data (n = 402 of 420; 95.7%) were included in this cohort study. We tested the hypotheses that preoperative left atrial size and function, left ventricular diastolic function, and their intraoperative changes were associated with postoperative atrial fibrillation. Normal left ventricular diastolic function was graded as 0 and with lateral e' velocity 10 cm/s or greater. Diastolic dysfunction was defined as lateral e' less than 10 cm/s using E/e' cutoffs of grade 1, E/e' 8 or less; grade, 2 E/e' 9 to 12; and grade 3, E/e' 13 or greater, along with two criteria based on mitral inflow and pulmonary wave flow velocities. A total of 230 of 402 patients (57.2%) had intraoperative diastolic dysfunction. Posterior pericardiotomy intervention was not significantly different between the two groups. A total of 99 of 402 patients (24.6%) developed postoperative atrial fibrillation. Patients who developed postoperative atrial fibrillation more frequently had abnormal left ventricular diastolic function compared to patients who did not develop postoperative atrial fibrillation (75.0% [n = 161 of 303] vs. 57.5% [n = 69 of 99]; P = 0.004). Of the left atrial size and function parameters, only delta left atrial area, defined as presternotomy minus post-chest closure measurement, was significantly different in the no postoperative atrial fibrillation versus postoperative atrial fibrillation groups on univariate analysis (-2.1 cm2 [interquartile range, -5.1 to 1.0] vs. 0.1 [interquartile range, -4.0 to 4.8]; P = 0.028). At multivariable analysis, baseline abnormal left ventricular diastolic function (odds ratio, 2.02; 95% CI, 1.15 to 3.63; P = 0.016) and pericardiotomy intervention (odds ratio, 0.46; 95% CI, 0.27 to 0.78, P = 0.004) were the only covariates independently associated with postoperative atrial fibrillation. Baseline preoperative left ventricular diastolic dysfunction on TEE, not left atrial size or function, is independently associated with postoperative atrial fibrillation. Further studies are needed to test if interventions aimed at optimizing intraoperative left ventricular diastolic function during cardiac surgery may reduce the risk of postoperative atrial fibrillation.

Comparing Left Atrial Low Voltage Areas in Sinus Rhythm and Atrial Fibrillation Using Novel Automated Voltage Analysis: A Pilot Study.

Low voltage areas (LVAs) have been proposed as surrogate markers for left atrial (LA) scar. Correlation between voltages in sinus rhythm (SR) and atrial fibrillation (AF) have previously been measured via point-by-point analysis. We sought to compare LA voltage composition measured in SR to AF, utilizing a high-density automated voltage histogram analysis (VHA) tool in those undergoing pulmonary vein isolation (PVI) for persistent AF (PeAF). We retrospectively analyzed patients with PeAF undergoing de novo PVI. Maps required ≥ 1,000 voltage points in each rhythm and had a standardized procedure (mapped in AF then remapped in SR post-PVI). We created six anatomical segments (AS) from each map: anterior, posterior, roof, floor, septal and lateral AS. These were analyzed by VHA, categorizing atrial LVAs into 10 voltage aliquots 0 - 0.5 mV. Data were analyzed using SPSS v.26. We acquired 58,342 voltage points (n = 10 patients, mean age: 67 ± 13 years, three females). LVA burdens of ≤ 0.2 mV, designated as "severe LVAs", were comparable between most AS (except on the posterior wall) with good correlation. Mapped voltages between the ranges of 0.21 and 0.5 mV were labeled as "diseased LA tissue", and these were found significantly more in AF than SR. Significant differences were seen on the roof, anterior, posterior, and lateral AS. Diseased LA tissue (0.21 - 0.5 mV) burden is significantly higher in AF than SR, mainly in the anterior, roof, lateral, and posterior wall. LA "severe LVA" (≤ 0.2 mV) burden is comparable in both rhythms, except with respect to the posterior wall. Our findings suggest that mapping rhythm has less effect on the LA with voltages < 0.2 mV than 0.2 - 0.5 mV across all anatomical regions, excluding the posterior wall.

An experimental model of chronic severe mitral regurgitation.

To develop a minimally invasive, reproducible model of chronic severe mitral regurgitation (MR) that replicates the clinical phenotype of left atrial (LA) and left ventricular dilation and susceptibility to atrial fibrillation. Under transesophageal echocardiographic guidance, chordae tendinae were avulsed using endovascular forceps until the ratio of regurgitant jet area to LA area was ≥70%. Animals survived for an average of 8.6±1.6months (standard deviation) and imaged with monthly transthoracic echocardiography (TTE). Animals underwent baseline and preterminal magnetic resonance imaging. Terminal studies included TTE, transesophageal echocardiography, and rapid atrial pacing to test inducibility of atrial tachyarrhythmias. Eight dogs underwent creation of severe MR and interval monitoring. Two were excluded-one died from acute heart failure, and the other had resolution of MR. Six dogs underwent the full experimental protocol; only one required medical management of clinical heart failure. MR remained severe over time, with a mean terminal regurgitant jet area to LA area of 71±14% (standard deviation) and regurgitant fraction of 52±11%. Mean LA volume increased over 130% (TTE: 163±147%, P=.039; magnetic resonance imaging: 132±54%, P=.011). Mean left ventricular end-diastolic volume increased by 38±21% (P=.008). Inducible atrial tachyarrhythmias were seen in 4 of 6 animals at terminal surgery, and none at baseline. Within the 6 dogs that successfully completed the full experimental protocol, this model replicated the clinical phenotype of severe MR, which led to marked structural and electrophysiologic cardiac remodeling. This model allowed for precise measurements at repeated time points and will facilitate future studies to elucidate the mechanisms of atrial and ventricular remodeling secondary to MR and the pathophysiology of valvular atrial fibrillation.

Gender Differences in Atrial Fibrosis and Cardiomyopathy Assessed by Left Atrial Low-Voltage Areas During Catheter Ablation of Atrial Fibrillation

Atrial myocardial degeneration predisposes to atrial fibrillation (AF), ischemic stroke, and heart failure. Studies suggest the presence of gender differences in atrial myocardial degeneration. This study aimed to delineate gender differences in the prevalence, predictors, and prognostic impact of left atrial low-voltage areas (LVAs). This observational study included 1,488 consecutive patients who underwent initial ablation for AF. Voltage mapping was performed after pulmonary vein isolation during sinus rhythm. LVAs were defined as regions where bipolar peak-to-peak voltage was <0.50mV. LVA prevalence was higher in women (38.7%) than in men (16.0%). High age, persistent form of AF, diabetes mellitus, and a large left atrium were shown to be common predictors in both gender categories. Heart failure and history of stroke/thromboembolic events were men-specific predictors of LVA existence. Women experienced more AF recurrence than men (31.1% vs 25.7%, p=0.027). LVA existence was significantly associated with increased AF recurrence in each gender category, with a respective hazard ratio, 95% confidence interval, and pvalue of 2.45, 1.87 to 3.22, and <0.0001 in men and 1.82, 1.33 to 2.49, and <0.0001 in women. In conclusion, LVA was more frequent in women than men, and predicted frequent AF recurrence irrespective of gender category.

Baseline left atrial low-voltage area predicts recurrence after pulmonary vein isolation: WAVE-MAP AF results.

Electro-anatomical mapping may be critical to identify atrial fibrillation (AF) subjects who require substrate modification beyond pulmonary vein isolation (PVI). The objective was to determine correlations between pre-ablation mapping characteristics and 12-month outcomes after a single PVI-only catheter ablation of AF. This study enrolled paroxysmal AF (PAF), early persistent AF (PsAF; 7 days-3 months), and non-early PsAF (>3-12 months) subjects undergoing de novo PVI-only radiofrequency catheter ablation. Sinus rhythm (SR) and AF voltage maps were created with the Advisor HD Grid™ Mapping Catheter, Sensor Enabled™ for each subject, and the presence of low-voltage area (LVA) (low-voltage cutoffs: 0.1-1.5 mV) was investigated. Follow-up visits were at 3, 6, and 12 months, with a 24-h Holter monitor at 12 months. A Cox proportional hazards model identified associations between mapping data and 12-month recurrence after a single PVI procedure. The study enrolled 300 subjects (113 PAF, 86 early PsAF, and 101 non-early PsAF) at 18 centres. At 12 months, 75.5% of subjects were free from AF/atrial flutter (AFL)/atrial tachycardia (AT) recurrence. Univariate analysis found that arrhythmia recurrence did not correlate with AF diagnosis, but LVA was significantly correlated. Low-voltage area (<0.5 mV) >28% of the left atrium in SR [hazard ratio (HR): 4.82, 95% confidence interval (CI): 2.08-11.18; P = 0.0003] and >72% in AF (HR: 5.66, 95% CI: 2.34-13.69; P = 0.0001) was associated with a higher risk of AF/AFL/AT recurrence at 12 months. Larger extension of LVA was associated with an increased risk of arrhythmia recurrence. These subjects may benefit from substrate modification beyond PVI.

Automated analysis of echocardiograms at diagnosis is able to predict prognosis in ATTR cardiomyopathy

Abstract Funding Acknowledgements Type of funding sources: None. Background Transthyretin amyloidosis cardiomyopathy (ATTR-CM) is progressive and ultimately fatal cause of heart failure. ATTR-CM often displays characteristic echocardiographic features, and manual measurements of both stroke volume and longitudinal strain are independent predictors of mortality. We sought to investigate whether automated analysis of echocardiographic parameters at the time of diagnosis were able to predict prognosis in this population. Methods We analysed all consecutive patients between 2006–2021 who underwent an echocardiogram at the time of diagnosis, and analysed their echocardiograms using artificial intelligence software that has been developed and validated by Us2.ai. Results We identified 1972 patients with ATTR-CM (age: 75.6±8.7 years, male: 86.9%), comprising of 1329 wild-type ATTR-CM and 643 hereditary ATTR-CM (V142I = 376, T80A = 171, other = 96). Patients with V142I had an increased relative wall thickness (P&amp;lt;0.001) lower stroke volume indexed (P&amp;lt;0.001), and worse longitudinal strain (P&amp;lt;0.001) than patients with wild-type and T80A ATTR-CM. In a multi-variable analysis of echocardiographic parameters selected a priori (interventricular septal diameter, relative wall thickness, left and right atrial area indexed, biplane stroke volume indexed, full thickness longitudinal strain, and E/e’ lateral), left atrial area indexed (HR=1.08, 95%CI[1.02–1.14], P=0.005), biplane stroke volume indexed (HR=0.96, 95%CI[0.94–0.98], P&amp;lt;0.001) and full thickness longitudinal strain (HR=1.04, 95%CI[1.01–1.08], P=0.009) all remained independent predictors of mortality. Conclusions Automated of analysis echocardiograms using artificial intelligence demonstrated that patients with V142I had more advanced cardiac disease at diagnosis. Automated measurements produced by artificial intelligence software are able to predict prognosis and identify the same parameters as those identified using manual analysis as powerful independent predictors of mortality.

The left atrial morphologic and functional parameters as predictors of paroxysmal atrial fibrillation in patients after ischemic stroke

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Cardiogenic source of embolism is the most common cause of non-lacunar ischemic stroke (IS). Identifying the patients with undiagnosed paroxysmal atrial fibrillation (PAF) may reduce the risk of recurrent cardiogenic strokes. Reliable predictors of PAF seems to be crucial for selection the patients to prolonged ECG monitoring after IS. Purpose To assess the feasibility of echocardiography in selecting the patients with highest risk of PAF. Methods We present the preliminary data of prospective cohort study of patients after IS or transient ischemic attack of unknown aetiology and possible cardiogenic origin. The examined group comprises of 40 consecutive patients without history of AF, capable to perform ECG recording. All patients included in the study had transthoracic echocardiography (TTE) prior the monitoring period. An offline analysis including left atrial functional and morphologic assessment was performed. Every patient enrolled in the study was equipped for 2 weeks with a mobile, on demand 1-minute single lead ECG recorder and was asked for at least two exams per day. After two weeks all recorded ECGs were checked for AF occurrence. The level of statistical significance was set at p&amp;lt;0.05. Results From 40 patients (aged 64,5 yrs in average) included in the study 45% were males; (n=18). 15% (n=6) of patients were diagnosed with PAF during ECG monitoring and comprised PAF subgroup, the rest of patients formed non PAF subgroup (nPAF). Mean number of ECG records was 56,5 per patient, during the monitoring period. There were no significant differences between PAF/nPAF in age, past medical history, and left ventricular (LV) size or systolic function. Patients from PAF group have statistically significant higher values of left atrial (LA) area and volume see table 1. PAF group has significantly lower (in absolute values) left atrial contraction strain – (LASct). There were no differences in conduit and reservoir LA (LASr) strains nor in LA ejection fraction. The highest PAF diagnosis efficacy according to area under the curve (AUC) of ROC curves was noted for parameters of: LA size: LA atrium volume index (LAVI) in 4 chamber view (AUC=0,82) and LA area index (0,81) LA contraction function: LASct (Avg) (AUC =0,80) LV diastolic function: E/E’ (0,81) For the threshold of 100% sensitivity the highest specificity was found for LA volume before active atrial contraction in 4 chamber view with cut-off value of &amp;gt;=37,6 ml (specificity 64,7%) (Figure 1.) and LASct (Avg) with cut-off value &amp;lt;=17% in absolute values (specificity 47,1%). Conclusions Both functional and morphologic parameters of LA can predict PAF diagnosis during ECG monitoring after IS. TTE after IS can be used to select patients who would benefit the most from prolonged ECG monitoring. High PAF detectability (100% sensitivity) with approximately 1/2 negative results of ECG monitoring can be achieved by both LA volumetric (LAV preA) and strain (LASct) analysis.

Effect of resistance exercise on cardiac perturbations and systolic performance: A cross-over randomized trial comparing volumes and techniques

ABSTRACT This study investigated the magnitude and time-course of resistance exercise (RE) technique induced transient cardiac perturbations. Twenty-four participants were assigned to one of four arms: sets to failure or non-failure with 8–10 repetition maximum (RM), and sets to failure or non-failure with 15RM. Echocardiographic and blood pressure (BP) data were recorded at baseline and 30 min, 6 h and 24 h post-exercise. In all groups end-systolic circumferential wall stress (cESS), and ratio of transmitral inflow velocities (E/A) were significantly decreased while posterior wall thickness (PWT), global circumferential strain (GCS), GCS strain rate (GCSR), global longitudinal strain rate (GLSR), and stroke volume (SV) were significantly increased for up to 6 h of follow-up. In the 15RM groups, left ventricular (LV) mass and interventricular septal thickness (IVST) were significantly increased, and left atrial (LA) area was significantly decreased (p < 0.05) compared to the 8–10 RM groups. In the 15RM groups, RE decreased global longitudinal strain (GLS) and increased ejection fraction (EF) (p<0.01). After RE, transient cardiac perturbations, the reduction in LA compliance, and the improvement in LV myofibril geometry were volume dependent and influenced more by sets to failure technique. RE increased GCS and reduced the afterload, thus helping to preserve SV and EF.

Targeted ablation of arrhythmogenic substrate in complex cases of very long-standing persistent atrial fibrillation: successful ablation of spatio-temporal dispersions

Abstract Funding Acknowledgements Type of funding sources: None. Introduction In persistent AF, outcomes after PVI alone is worse as the pathophysiology remains unclear. Prolonged AF duration is an independent predictor for worse success rates after catheter ablation. In this study, we investigated efficacy and safety of ablation of spatio-temporal dispersions, as additional ablation strategy after PVI in patients with long-standing persistent AF. Methods All consecutive patients with long-standing persistent AF treated with an AI-based algorithm for detection of spatio-temporal dispersion in our institution between 05/21 and 10/22 were included (n = 41, see table 1). The procedure was done using a high-density 3D-Map and an algorithm for detection of right and left atrial areas with spatio-temporal dispersion (DISPERS). Ablation of DISPERS was aiming at homogenizing, dissecting, isolating or connecting DISPERS areas to non-conducting structures. Follow-up contained regular visits at our out-patient-clinic and repetitive 7 day Holter ECGs. Late recurrence (LR) was defined as recurrence after 90 days or as recurrence, which caused further ablation. All complications requiring intervention or causing long-term sequelae were classified as major complications. Results In 24/41 pts (58.5%), the DISPERS guided ablation was the first AF ablation. Patients were suffering from very long-standing persistent AF with a mean AF duration of 64.89 ± 54.77 months. Additional to circumferential PVI, ablation of all detected left atrial (100%) and right atrial (68.3%) DISPERS areas was performed, leading to significant slowing of AF cycle length (mean 23.3%) or termination of AF to AT (5/41, 12.2%) or direct conversion to SR (6/41, 14.6%). One major complication occurred (1/41 (2.4%), pseudoaneurysm, resolving after manual compression). Three patients (7.3%) required temporary external pacing due to delayed sinus recovery after the procedure. No patient was in need of permanent pacemaker implantation. LR occurred in 25 patients (61.0 %): In 8/25 patients (32 %), LR was solely AF, whereas in 15/25 patients (60%) LR was a left AFlutt. In 2 patients (8%), AF and left AFlutt was detected. During a follow-up of 231 ± 129 days, 72.9 % of patients remained in sinus rhythm undergoing 1.6 ± 0.68 ablations (s. Figure 1; 4,9% of patients on AAD). Additionally, Figure 2 illustrates the AF-free outcome in all patients. Conclusion Ablation of arrhythmogenic substrate identified by spatio-temporal dispersion yielded in this cohort of extensively long-standing persistent AF patients in high success rates regarding elimination of AF. Most arrhythmia recurrences were reentrant AT. After a total of 1.6 procedures, freedom from AF and AT was &amp;gt;72%. Despite prolonged procedure times, complication rates remained very low. Extending study population and follow-up is needed to evaluate long-term efficacy of dispersion-guided ablation.

Left atrial Strain as a predictor of atrial fibrillation recurrence after catheter ablation

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Atrial fibrillation (AF) is one of the most common cardiac arrhythmias. In arrhythmology, catheter ablation methods are successfully used in the treatment of AF. Objective To assess the significance of left atrial (LA) longitudinal deformity in predicting AF recurrence after catheter ablation. Research material and methods: The study was carried out on the basis of NJSC "National Scientific Cardiac Surgery Center" in the Department of Interventional Arrhythmology. The study included 150 patients, whose average age was 62.4 ± 7.47 years. All patients underwent catheter ablation of the pulmonary veins. Patients were divided into 2 groups depending on the effectiveness of ablation: with recurrent AF (47) and patients who maintained sinus rhythm for 12 months (103). Heart parameters were assessed in two-dimensional (2D) conventional and speckle-tracking echocardiography of the left atrium (LA). Results According to the results of Speckle-tracking echocardiography, the peak values of longitudinal and contractile LA deformity were significantly lower in the group where AF relapsed soon and amounted to -17.4319±0.52 and -22.9194±1.13, respectively (p&amp;lt;0, 0001). According to the results of an echocardiographic study, the LA volume was 100.10±28.5 ml in the first group and 74.85±14.44 ml in the 2nd group (p&amp;lt;0.01), which exceeds normal values. Statistical difference revealed (p&amp;lt;0.01), such indicators as the indexed volume of the LA and its area, which amounted to 47.27±9.21 ml/m²; 38.13±6.85 ml/m²; and 26.61±3.37 cm²; 22.72±3.12 cm², respectively. LVML in group 1 was 225.3±44.1, in group 2 160.29±40.61 (p&amp;lt;0.01), LVMI was 112±19.25 and 83.30±20.17 (p&amp;lt;0.01). Correlation analysis revealed a positive relationship between AF recurrence and LA area (r=0.599; p&amp;lt;0.01), longitudinal LA deformity (r=-0.804), RA area (r=0.479; p&amp;lt;0.01), LVMI (r=0.557; p&amp;lt;0.01), LVMI (r=0.367; p&amp;lt;0.01), LV EDR (r=0.381; p&amp;lt;0.01), LV ESR (r=0.375; p&amp;lt;0 .01). Analysis of the ROC curve of the relationship between relapse and LA volume showed that the area under the ROC curve was 0.786 ± 0.045 with 95% CI: 0.679-0.858. Assessing the relationship between AF recurrence and LA area, the area under the ROC curve was 0.783 ± 0.043 with 95% CI: 0.699-0.867. The threshold value of the volume and area of the LA at the cut-off point is 81.5 (sensitivity and specificity were 70.2% and 66%%) and 24.5 (sensitivity and specificity were 68.1% and 68.9%) ( p&amp;lt;0.001). Conclusion Speckle tracking echocardiography is a valuable tool for evaluating left atrial function in patients with AF and may be of diagnostic value for the prognostic detection of AF recurrence in patients after catheter ablation. Evaluation of echocardiographic parameters in patients with AF revealed that an increase in such parameters as the volume and area of the left and right atrium, LVMI, MMLV, LV EDD, LV ESD has a moderate positive correlation with recurrent AF.

Predictive value of clinical risk scores for determination of left atrial low voltage area and arrhythmia recurrences in patients undergoing atrial fibrillation ablation

Abstract Funding Acknowledgements Type of funding sources: None. Background Presence of left atrial low voltage area (LVA) is an independent predictor of atrial tachyarhythmia (ATa) recurrences after atrial fibrillation (AF) ablation. Thus identifying patients with LVA by using non-invasive methods is an important endeavour. Purpose In this study; we investigated the predictors of LVA and postablation recurrences especially focusing on clinical risk scores. Methods We enrolled 328 consecutive patients who underwent initial AF ablation procedure using high density mapping. LVAs were assessed and segmental distribution was noted in each patient. CHA2DS2-VASc, HATCH, APPLE and SPEED scores were calculated. Predictive value and arrhythmia recurrences were evaluated. Results Two hundred and twenty one patients (67.37%) were paroxysmal AF and 107 (32.62%) patients were non-paroxysmal AF at the time of ablation. Mean CHA2DS2-VASc score was 1.88±1.66, mean APPLE score was 1.20±1.20, HATCH score was 0.93±1.00 and SPEED score was 1.54±1.27 in the whole study group. LVA was detected in 131 patients (39.93%). Female gender [OR:2.94, CI: 1.34-6.43, p=0.007), non-paroxsymal AF (OR: 2.49 CI:1.13-5.46, p=0.023), APPLE score ≥1 (OR:1.69 CI:1.12-2.55, p=0.012) and SPEED score ≥ 1 (OR: 1.47 CI:1.00-2.14, p=0.045] were independent predictors for the presence of LVA in multivariate analysis. Presence of LVA (OR:1.98; CI:1.13-4.15; p=0.017) and HT (OR:2.00; CI:1.19-3.38; p=0.009) were the independent predictors of recurrences. Conclusion Higher clinical scores are associated with more LVA which is associated with ATa recurrence. However the predictive value of these risk scores is limited. Better risk scoring systems are needed to precisely identify the underlying atrial substrate in this patient group.

The relationship between high dominant frequency and low voltage areas in patients with atrial fibrillation: digital twin study

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): a grant [2022R1I1A1A0106342211] from the Basic Science Research Program run by the National Research Foundation of Korea (NRF) which is funded by the Ministry of Science, ICT &amp; Future Planning (MSIP) Background It has been suggested that the high dominant frequency (DF) site plays an atrial fibrillation (AF) driver, but its relationship with the atrial substrate voltage map (Vm) in the entire chamber AF map has yet to be studied. We explored the relationship between the DF site during AF and Vm in the entire chamber maps by applying the human left atrial (LA) electroanatomical map (EAM) to the digital twin AF map. Methods We acquired LA substrate Vm (at sinus rhythm, &amp;gt;800 points bipolar electrograms) of 110 patients with persistent AF (male 72.7%, 58.7±9.8 years old) who underwent AF catheter ablation. We applied EAM to digital twins (0.4 million nodes), reflecting anatomy, histology, and electrophysiology. We evaluated the highest 10% DF areas for 6 sec after inducing virtual AF. The correlation between the highest 10% DF and the low Vm areas (&amp;lt;0.2mV) was evaluated in the LA region of 10 segments. Results The mean voltage of the entire LA area was 1.96±0.85 mV (2.19±0.82 mV extra-PV area, 1.33±0.93 mV PV area) in 110 patients. The correlation between low Vm and high DF areas was not significant in the entire LA (r=0.106, p&amp;lt;0.001), extra-PV (r=0.157, p&amp;lt;0.001), and PV (r=0.079, p=0.097) areas. In the LA 10 segment regional analysis, 72 patients (65.5%) showed the co-localization of the highest DF in the region with the lowest Vm, and 14 patients (12.7%) had the lowest Vm segment in the region with the highest DF. The mean voltage where high DF appeared was 0.69±1.35 mV, and the mean voltage of the region where high DF did not appear was 0.59±1.15 mV (p=0.171). Conclusion High DF site, a parameter representing a localized focal source, had statistically significant but very poor correlations with LA extra-PV voltage substrate in patients with persistent AF.

Fetal Cardiac Function at Midgestation in Women Who Subsequently Develop Gestational Diabetes

Fetuses in women with gestational diabetes (GD) compared with those without GD show evidence of subclinical cardiac functional and morphological changes. However, it is uncertain whether glycemia or the adverse maternal underlying risk factor profile is the main driver for fetal cardiac remodeling. To assess cardiac morphology and function at midgestation in fetuses of mothers prior to development of GD and compare them with those of unaffected controls. During this prospective nonintervention screening study at 19 to 23 weeks' gestation, fetal cardiac morphology and function were assessed in all participants. Pregnancy complications were obtained from the medical records of the women. Fetal cardiac morphology and function were assessed in all participants at Harris Birthright Research Institute at King's College Hospital, London, United Kingdom. Participants included pregnant women with singleton pregnancy who attended their routine fetal ultrasound examination at midgestation and agreed to participate in the Advanced Cardiovascular Imaging Study in pregnancy. Comparison of fetal cardiac morphology and function between mothers who subsequently developed GD and those who did not develop GD. This was a prospective nonintervention screening study of 5620 women with singleton pregnancies at 19 to 23 weeks' gestation. Conventional and more advanced echocardiographic modalities, such as speckle tracking, were used to assess fetal cardiac function in the right and left ventricle. The morphology of the fetal heart was assessed by calculating the right and left sphericity index. The 5620 included patients had a mean age of 33.6 years. In 470 cases, the women were diagnosed with GD after the midgestation echocardiographic assessment (8.4%). Women with GD, compared with the non-GD group, were older, had higher BMI, higher prevalence of family history of diabetes, non-White ethnicity, chronic hypertension, and GD in a previous pregnancy. In fetuses of the GD group compared with the non-GD group, there was mild increase in interventricular millimeter thickness (0.04; 95% CI, 0.03-0.06 mm) and left atrial area (0.04; 95% CI, 0.04-0.05), whereas left and right functional indices were comparable between groups with the exception of left ventricular ejection fraction, which was marginally improved in the GD group (0.02; 95% CI, 0.03-0.03). This study demonstrates that prior to development of GD, there was mild alteration in fetal cardiac morphology without affecting cardiac function. This suggests that the adverse maternal risk factor profile and not only the glycemia might contribute to cardiac remodeling noted in fetuses of women with GD.

Low atrial natriuretic peptide to brain natriuretic peptide ratio is associated with left atrial remodeling.

Atrial natriuretic peptide (ANP) deficiency is thought to be one of the causes of heart failure induced by atrial fibrillation (AF). Although ANP deficiency is thought to occur as a result of atrial remodeling, data to explain this mechanism are limited. The purpose of this study was to investigate the association between ANP and left atrial remodeling or prognosis of heart failure in patients with AF ablation. In total, 373 consecutive patients who underwent initial ablation for persistent AF [age, 67 ± 10 years; female, 97 (26%)] were retrospectively enrolled. ANP and brain natriuretic peptide (BNP) were measured before the procedure and the ANP/BNP ratio was calculated. Left atrial volume index, left atrial appendage emptying velocity, and left atrial low-voltage areas (LVAs) were used as left atrial-remodeling parameters. The primary outcome of heart failure was defined as the composite of all-cause death or hospitalization due to worsening heart failure. The median ANP level was 116 (71-178) pg/ml and the median ANP/BNP ratio was 0.65 (0.46-1.00). The ANP/BNP ratio decreased with increasing left atrial volume index or LVAs and with decreasing left atrial appendage emptying velocity. During the 5-year follow-up, freedom from the primary outcome was significantly lower in patients with ANP/BNP ratio ≤0.65 than in those with ANP/BNP ratio >0.65 (84.6% versus 95.6%, P < 0.01). Secretion of ANP relative to BNP decreased with progression of left atrial remodeling in patients with AF ablation. Furthermore, prognosis of heart failure was poor in patients with a low ANP/BNP ratio.

Left atrial area as a simple predictor of paroxysmal AF in patient with acute ischemic stroke

Abstract Funding Acknowledgements Type of funding sources: None. Introduction The most important cardiogenic reason of acute Ischemic stroke (AIS) is atrial fibrillation (AF). Left atrial (LA) enlargement (atriopathy) is one of the risk factors of atrial fibrillation. Basic bio-metric measurements (height , weight and BSA) in patients with AIS can be challenging due to immobilization, therefor estimation of LA size using recommended parameter (left atrial volume index) is often not possible in every day practice. Aim To assess the discriminant value of different LA size parameters for detection of known paroxysmal AF in patients with acute ischemic stroke. To estimate best cut-off value of LA size parameters which predict presence of paroxysmal AF in patients with AIS. Materials and methods A database of 663 consecutive patients admitted to a neurology department with the diagnosis of acute ischemic stroke (AIS) who underwent transthoracic echocardiography (TTE) were analysed. After exclusion of 117 patient with persistent or permanent AF (present during TTE) the examined group comprised of 546 patients. Average age was 70,1years (20-97yrs), 53% were women. From the examined group 56 (10,3%) had known (from past medical history or diagnosed during the hospitalization in ecg, telemetry or holter monitoring) paroxysmal AF. 35,6% of examined patients required bedside echocardiography due to immobilization. The predictive values for the presence of paroxysmal AF were assessed for: LA antero-posterior diameter (LAd) in parasternal long axis , LA area in four chamber diameter (LAA), as well as LAd and LAA indexed to aorta diameter(Ao) (innere-to-inner method on the level of sinus of Valsalvy). Receiver Operating Characteristic (ROC) curves, area under the curve (AUC), specificity and sensitivity were analysed, Younden index was used for the estimation of cut-off values. Results ROC – curves of all examined parameters are presented in fig. 1. The AUC of LAd, LAA, LAd/Ao and LAA/Ao were: 0,60; 0,73 0,72; 0,81 respectively. Differences in AUC were statistically significant (p&amp;lt;0,05). The best cut of value for LAA/Ao was 7,2cm2/cm , with sensitivity of 0,90 and specificity of 0,59. 112 of 490 (23%) patient without known paroxysmal AF exceeded the estimated cut-off point. Conclusions 1. In 1/3 of patients with AIS the assessment of recommended parameter of LA size (LAVI) can be difficult in clinical practice. 2. A simple, widely available parameter of left atrial size (LAA/Ao) has the best predictive value for the detection of patients with known paroxysmal AF. 3. Nearly ¼ of patients without known AF presenting with AIS have atriopathy which can be connected to not recognized arrhythmia. 4. LAA/Ao can be used as a simple, widely available parameter for the selection of patient for more profound prospective screening for AF in patients with AIS.

Electrocardiographic and echographic predictive factors of silent AF in ESUS stroke

Stroke is a major public health problem, the leading cause of acquired disability in adults and the third leading cause of death worldwide. Ischaemic stroke accounts for 80% of all strokes. Approximately 20% of DVAs are associated with atrial fibrillation (AF). However, 25% remain of undetermined origin (ESUS) with a risk of recurrence under anti-platelet therapy greater than 4% per year. In this population, the challenge is the detection of subclinical atrial fibrillation (AF), the incidence of which could reach 25%. The effectiveness of the probabilistic anticoagulation strategy has not been demonstrated in this population, making it necessary to identify ESUS patients at high risk of subclinical AF. The aim of this study is to determine the incidence and the electrocardiographic and echographic predictive factors of silent AF in ESUS stroke. Monocentric descriptive and analytical historical cohort study conducted at the Neurology Department between January 2016 and December 2020. Three hundred Esus patients were included. In our study, 42/300 (14%) patients had at least one episode of AF (> 30 s). In univariate analysis, the variables significantly associated with sluggish AF in ESUS-type stroke were age greater than or equal to 60 years (P = 0.004, OR = 3.76), female gender (P = 0.045, OR = 1.94), P-wave markers (abnormal axis, prolonged duration), P-wave dispersion (P < 10−3), a high number of supraventricular extrasystoles (P < 10−3, OR = 1.007), OG dilatation (P < 10−3, OR = 1.61) and diastolic dysfunction (P < 10−3, OR = 30.25). In multivariate analysis, p-wave dispersion (P < 10−3, OR = 57.77), number of SVSEs > 500/24 h (P < 10−3, OR = 185.83), and left atrial area > 20 cm2 (P < 10−3, OR = 74.7) appeared to be independent predictors of the occurrence of a subclinical AF episode. In this cohort of ESUS patients, several factors appeared to be predictive of subclinical AF. This result is consistent with the finding of several studies that the subgroup of ESUS patients with these factors appeared to benefit from probabilistic anticoagulation in preventing cerebral infarct recurrence.

PO-01-214 DEEP LEARNING EVALUATION OF ECHOCARDIOGRAMS TO IDENTIFY OCCULT ATRIAL FIBRILLATION

Atrial fibrillation (AF) can often be missed by routine screening given its frequently paroxysmal and asymptomatic presentation. Deep learning algorithms can identify patients with paroxysmal AF from sinus electrocardiograms. Transthoracic echocardiograms (TTEs) may provide additional structural information complementary to ECGs that could also be used to help identify occult AF. We sought to determine whether deep learning evaluation of echocardiograms of patients in normal sinus rhythm could predict concurrent atrial fibrillation. We identified patients who had TTE performed between 6/2004 and 6/2021. Cases were defined as patients who had a TTE in normal sinus rhythm (NSR) with AF documented on ECG within 90 days before/after the TTE. Controls had a NSR TTE (by report and confirmed by lack of noted mitral A wave velocity) and no documented AF within 90 days by ECG or ICD diagnosis. We trained a video-based convolutional neural network using TTE parasternal long axis (PLAX) videos to predict concurrent AF. Model performance was compared to AF prediction by logistic regression using clinical variables (age, sex, heart failure, hypertension, cerebrovascular disease, peripheral arterial disease, diabetes, height, weight, smoker), CHADS2VASc score, and left atrial (LA) size on TTE. Model was trained on 57,681 TTEs of patients who were on average 66.2 years old (SD 16.9), 44.9% female, with a mean CHADS2VASc score of 3.1 (SD 2.1) and LA area of 19.7cm2 (SD 5.8). When tested on a held-out sample of 7,283 TTEs, the model predicted the occurrence of atrial fibrillation within 90 days of a sinus TTE with an AUC of 0.71 (0.69-0.73). Using the max accuracy threshold, the PPV was 0.20 and the NPV was 0.95. The model performed better than predicting AF using clinical risk factors (AUC 0.67), LA area (AUC 0.63), and CHADS2VASc (AUC 0.61). A deep learning model predicted the occurrence of atrial fibrillation from TTEs moderately well, better than clinical variables or LA size alone. This may open up additional opportunities for screening patients for occult AF.

PO-02-065 CATHETER ABLATION WITH TERMINATION OF PERSISTENT ATRIAL FIBRILLATION USING SPATIOTEMPORAL DISPERSION

Several strategies of electrogram (EGM) guided catheter ablation of atrial fibrillation (AF) have been previously described. A spatiotemporal dispersion (SD) ablation strategy targeting AF drivers with very high termination rates has been reported; however, these sites have not been well characterized. The purpose of this study is to validate the prior experience with SD ablation in the persistent AF cohort and further characterize the regions of AF termination. Consecutive patients with persistent AF undergoing radiofrequency catheter ablation were included. Electroanatomic mapping of SD areas was performed during AF. Ablation was delivered initially at sites of continuous SD, followed by pulmonary vein isolation in all patients. If AF did not terminate, additional regions of intermittent SD were ablated. If AF terminated to atrial tachycardia or flutter, additional electroanatomic mapping and ablation was performed to achieve sinus rhythm. Representative EGMs at sites of continuous SD, intermittent SD, and no SD are shown in Figures 1A, 1B, and 1C, respectively. Left atrial (LA) volume and surface area, termination sites, and procedural characteristics are reported. A total of 20 consecutive patients (13 male, 67 ± 9 years) with persistent AF (median time from diagnosis 5 years) undergoing ablation were included in the study. The majority of continuous SD was seen on the anterior wall (18/20 patients) and septum (15/20 patients) and occasionally on the posterior wall (8/20 patients). 17/20 (85%) patients successfully terminated to sinus rhythm during the procedure. The majority of the termination sites were on the septum and anterior wall (12/17) with none on the posterior wall. LA volume by echocardiography was smaller in the termination group (84 vs. 105 mL, p < 0.01) and fluoroscopy use was less in the termination group (2.3 vs. 4.8 min, p = 0.03). There was no difference in ejection fraction, LA surface area, radiofrequency time, or procedure time (p = NS). A very high termination rate of persistent AF was achievable with ablation of SD regions. These regions likely represent drivers of AF and seem to localize predominantly on the septum and anterior wall of the LA, and rarely on the posterior wall. Ablation incorporating SD mapping may allow for patient-tailored approach to AF ablation.