Bidirectional Association Among the Type of Atrial Fibrillation, Sleep-Disordered Breathing Severity, Heart Failure Progression, and Left Atrial Enlargement, in Patients with Atrial Fibrillation.

This study aimed to clarify (1) the association among the atrial fibrillation (AF) type, sleep-disordered breathing (SDB), heart failure (HF), and left atrial (LA) enlargement, (2) the independent predictors of LA enlargement, and (3) the effects of ablation on those conditions in patients with AF. The study's endpoint was LA enlargement (LA volume index [LAVI] ≥ 78 mL/m2).Of 423 patients with nonvalvular AF, 236 were enrolled. We evaluated the role of the clinical parameters such as the AF type, SDB severity, and HF in LA enlargement. Among them, 141 patients exhibiting a 3% oxygen desaturation index (ODI) of ≥ 10 events/hour underwent polysomnography to evaluate the SDB severity measured by the apnea-hypopnea index (AHI). The LA enlargement and HF were characterized by the LA diameter/LAVI, an increase in the B-type natriuretic peptide level, and a lower left ventricular ejection fraction.This study showed that non-paroxysmal AF (NPAF) rather than paroxysmal AF (PAF), the SDB severity, LA enlargement, and HF progression had bidirectional associations and exacerbated each other, which generated a vicious cycle that contributed to the LA enlargement. NPAF (OR = 4.55, P < 0.001), an AHI of ≥ 25.10 events/hour (OR = 1.55, P = 0.003), and a 3% ODI of ≥ 15.43 events/hour (OR = 1.52, P = 0.003) were independent predictors of an acceleration of the LA enlargement. AF ablation improved the HF and LA enlargement.To break this vicious cycle, AF ablation may be the basis for suppressing the LA enlargement and HF progression subsequently eliminating the substrates for AF and SDB in patients with AF.

Left atrial function in middle-aged men and women with and without paroxysmal atrial fibrillation: Data from the Akershus Cardiac Examination (ACE) 1950 study.

PURPOSE: To assess left atrial (LA) function in individuals with known paroxysmal atrial fibrillation (AF) compared with healthy and nonhealthy individuals without atrial fibrillation. METHODS: The Akershus Cardiac Examination 1950 Study included 3,706 individuals all born in 1950. LA strain assessment of reservoir (LASr), conduit (LAScd) and contractile (LASct) functions were performed in all participants by investigators blinded to clinical data. Participants with cardiovascular disease, obesity, diabetes, pulmonary or renal disease were defined as nonhealthy, and those without as healthy. Patients with paroxysmal AF were identified through medical history and ECG documentation. RESULTS: LA strain assessment was feasible in 3,229 (87%) of the participants (50% women). The healthy group (n = 758) had significantly higher LASr and LAScd than the nonhealthy (n = 2,376), but LASct was similar between the groups. Participants with paroxysmal AF had significantly lower values of all strain parameters than the other groups. Multivariable logistic regression showed a significantly reduced probability of having AF per standard deviation increase in LASr and LASct. A nonlinear restricted cubic spline model fitted better with the association of LASr with paroxysmal AF than the linear model, and LA strain values below the population mean associated with an increased probability of having AF, but for values above the population mean no such association was present. CONCLUSION: Compared to participants without AF, those with known paroxysmal AF had significantly lower values of all LA strain parameters during sinus rhythm. Lower values of LA strain were associated with a significantly increased probability of having AF.

Screening for Unrecognized HFpEF in Atrial Fibrillation and for Unrecognized Atrial Fibrillation in HFpEF.

Because of the bidirectional relationship between atrial fibrillation (AF) and heart failure with preserved ejection fraction (HFpEF), individuals with either condition require consideration of screening for the other. In this review, we summarize current evidence and rationale for screening for occult HFpEF in adults with clinical AF; and occult AF in patients with clinically recognized HFpEF. Assessment of pretest probability for occult HFpEF in symptomatic AF patients may help guide additional testing such as exercise right heart catheterization to diagnose HFpEF and guide HFpEF-specific therapies. In patients with HFpEF, AF screening will identify cases of occult AF where anticoagulation may decrease stroke risk, and correlation of previously unknown AF episodes with paroxysmal symptoms may prompt consideration for rhythm control. Therefore, screening may help clinicians understand the etiology of the often-overlapping symptoms, and it may help guide treatments to slow progression of both conditions and their complications.

Long-term cardiac computed tomography follow-up after left atrial appendage occlusion.

BACKGROUND: Left atrial appendage occlusion (LAAO) is performed increasingly, but long-term follow-up imaging data are lacking. AIMS: The aim of this study was to evaluate the safety and durability of the Amplatzer Amulet device >4 years after LAAO. METHODS: This was a prospective observational cohort study including 52 patients implanted with the Amplatzer Amulet device at Aarhus University Hospital, Denmark. A >4-year follow-up cardiac computed tomography (CT) scan after LAAO was performed and compared with the results from the 2-month and 12-month scans. The primary outcome was left atrial appendage (LAA) sealing based on distal LAA contrast patency and peridevice leakage (PDL), stratified into complete occlusion (grade 0 [G0]) and grade 1-3 leakage (G1-3), respectively. Secondary outcomes were low- and high-grade hypoattenuated thickening (HAT), device-related thrombosis (DRT) and device durability. RESULTS: The median (interquartile range [IQR]) follow-up time from LAAO to the latest CT scan was 5.8 years (4.5; 6.3). At 2-month (n=52), 12-month (n=27) and >4-year CT follow-ups (n=52), rates of both complete occlusion (33%, 37%, 35%) and G2 leaks (52%, 52%, 48%) remained stable. Rates of G1 leaks varied (14%, 4%, 6%) and G3 leaks rose (2%, 7%, 12%) from earliest to latest follow-up. The median left atrial (LA) volume increased from 127 mL (96; 176) to 144 mL (108; 182) and 147 mL (107; 193). No DRT was found. The structural device integrity was preserved. CONCLUSIONS: This study indicates a stable LAA sealing status throughout the follow-up period, emphasising the importance of the procedural result in avoiding PDL. Few patients displayed PDL progression, which might partly be related to LA remodelling with increasing volume. The long-term device durability appears excellent. Larger studies are warranted to confirm these findings.

Left atrial appendage closure in a patient previously implanted with an interatrial shunt device: a case report.

Patients with previous interatrial shunt device (IASD) implantation may face greater challenges during future left atrial interventional procedures. Herein, we report the first case of left atrial appendage closure (LAAC) in a patient with previous IASD implantation. The patient successfully underwent LAAC using the LAmbre device without complications.

The Impact of Sodium-Glucose Cotransporter-2 Inhibitors on Atrial Electromechanical Conduction Time.

OBJECTIVE: This study aims to explore the impact of sodium-glucose cotransporter-2 (SGLT-2) inhibitors, a newer class of oral antidiabetic drugs, on atrial electromechanical delay (EMD) in patients with type 2 diabetes mellitus (DM). This is particularly relevant given the significantly higher incidence of atrial fibrillation (AF) in diabetic patients compared to the general population. Atrial electromechanical delay is recognized as an important factor influencing the development of atrial fibrillation. METHODS: This study included 30 type 2 DM patients (53.3% female, mean age 60.07 ± 10.03 years), initiating treatment with SGLT-2 inhibitors. The patients were assessed using echocardiography at baseline and again at 6 months, focusing on basic echocardiographic parameters and atrial electromechanical delay times (EMD) measured via tissue Doppler imaging. RESULTS: No significant changes were observed in intra-atrial EMD times. However, significant reductions were noted in interatrial EMD times, decreasing from 15.13 ± 5.87 ms to 13.20 ± 6.12 ms (P = 0.029). Statistically significant shortening occurred in lateral pulmonary acceleration (PA) times (from 58.73 ± 6.41 ms to 54.37 ± 6.97 ms, P < 0.001), septal PA times (from 50.90 ± 6.02 ms to 48.23 ± 5), and tricuspid PA times (from 43.60 ± 6.28 ms to 41.30 ± 5.60 ms, P = 0.003). Additionally, there was a significant reduction in the E/e' ratio from 8.13 ± 4.0 to 6.50 ± 2.37 (P = 0.003). CONCLUSION: SGLT-2 inhibitors might positively influence atrial electromechanical conduction, reducing DM-related functional impairments and the risk of arrhythmias, particularly AF.

Multiscale dilated convolutional neural network for Atrial Fibrillation detection.

Atrial Fibrillation (AF), a type of heart arrhythmia, becomes more common with aging and is associated with an increased risk of stroke and mortality. In light of the urgent need for effective automated AF monitoring, existing methods often fall short in balancing accuracy and computational efficiency. To address this issue, we introduce a framework based on Multi-Scale Dilated Convolution (AF-MSDC), aimed at achieving precise predictions with low cost and high efficiency. By integrating Multi-Scale Dilated Convolution (MSDC) modules, our model is capable of extracting features from electrocardiogram (ECG) datasets across various scales, thus achieving an optimal balance between precision and computational savings. We have developed three MSDC modules to construct the AF-MSDC framework and assessed its performance on renowned datasets, including the MIT-BIH Atrial Fibrillation Database and Physionet Challenge 2017. Empirical results unequivocally demonstrate that our technique surpasses existing state-of-the-art (SOTA) methods in the AF detection domain. Specifically, our model, with only a quarter of the parameters of a Residual Network (ResNet), achieved an impressive sensitivity of 99.45%, specificity of 99.64% (on the MIT-BIH AFDB dataset), and an [Formula: see text] score of 85.63% (on the Physionet Challenge 2017 AFDB dataset). This high efficiency makes our model particularly suitable for integration into wearable ECG devices powered by edge computing frameworks. Moreover, this innovative approach offers new possibilities for the early diagnosis of AF in clinical applications, potentially improving patient quality of life and reducing healthcare costs.

Targeting subclinical ventricular dysfunction in atrial fibrillation: What can myocardial work add?

Atrial fibrillation (AF) could impact on left ventricular function leading to a sublinical myocardial dysfunction, as identified by myocardial work parameters in a population-based cohort of AF patients compared with healthy individuals; factors associated with these parameters are also shown. SBP: systolic blood pressure; LAVI: left atrial volume index.

Arrhythmias of the Left Atrial Appendage: Approaches to the Definitive Management of Atrial Tachycardia from the LAA Stump.

The left atrial appendage (LAA) is now recognized as a significant contributor to arrhythmia and thromboembolism in patients with a history of atrial fibrillation. Thoracoscopic exclusion of the LAA is made possible with the AtriClip device. In this report, we describe the case of a 65-year-old man with history of multiple left atrial ablation procedures and LAA clipping. He developed a microreentrant atrial tachycardia originating from the anterior base of the LAA stump, underwent complete isolation of the LAA, and had subsequent resolution of arrhythmogenic activity from the residual LAA stump.

Validity of a smartwatch for detecting atrial fibrillation in patients after heart valve surgery: a prospective observational study.

OBJECTIVES: Atrial fibrillation (AF) is a common early arrhythmia after heart valve surgery that limits physical activity. We aimed to evaluate the criterion validity of the Apple Watch Series 5 single-lead electrocardiogram (ECG) for detecting AF in patients after heart valve surgery. DESIGN: We enrolled 105 patients from the University Hospital of North Norway, of whom 93 completed the study. All patients underwent single-lead ECG using the smartwatch three times or more daily on the second to third or third to fourth postoperative day. These results were compared with continuous 2-4 days ECG telemetry monitoring and a 12-lead ECG on the third postoperative day. RESULTS: On comparing the Apple Watch ECGs with the ECG monitoring, the sensitivity and specificity to detect AF were 91% (75, 100) and 96% (91, 99), respectively. The accuracy was 95% (91, 99). On comparing Apple Watch ECG with a 12-lead ECG, the sensitivity was 71% (62, 100) and the specificity was 92% (92, 100). CONCLUSION: The Apple smartwatch single-lead ECG has high sensitivity and specificity, and might be a useful tool for detecting AF in patients after heart valve surgery.

Atrial Tachycardia Masquerading as Atrial Fibrillation Following Bi-Atrial MAZE Procedure.

A 34-year-old woman presented with palpitations and paroxysmal atrial fibrillation (AF). Workup revealed anterior mitral valve prolapse with severe mitral regurgitation. She was referred for surgical repair and underwent a mitral valve replacement, tricuspid valve repair, and bi-atrial cryoMAZE procedure with left atrial appendage ligation. Her postoperative course was complicated by inferior wall myocardial infarction. She subsequently presented with palpitations and underwent electrophysiology study and ablation. This case illustrates pitfalls associated with the surgical MAZE procedure and highlights the challenges in postoperative atrial arrhythmias diagnosis and management.

Impact of wall thickness on the tissue cooling effect of cryoballoon ablation.

AIMS: Understanding of the tissue cooling properties of cryoballoon ablation during pulmonary vein (PV) isolation is lacking. The purpose of this study was to delineate the depth of the tissue cooling effect during cryoballoon freezing at the pulmonary venous ostium. METHODS AND RESULTS: A left atrial-PV model was constructed using a three-dimensional printer with data from a patient to which porcine thigh muscle of various thicknesses could be affixed. The model was placed in a 37°C water tank with a PV water flow at a rate that mimicked biological blood flow. Cryofreezing at the PV ostium was performed five times each for sliced porcine thigh muscle of 2, 4, and 6 mm thickness, and sliced muscle cooling on the side opposite the balloon was monitored. The cooling effect was assessed using the average temperature of 12 evenly distributed thermocouples covering the roof region of the left superior PV. Tissue cooling effects were in the order of the 2, 4, and 6 mm thicknesses, with an average temperature of -41.4 ± 4.2°C for 2 mm, -33.0 ± 4.0°C for 4 mm, and 8.0 ± 8.7°C for 6 mm at 180 s (P for trend <0.0001). In addition, tissue temperature drops were steeper in thin muscle (maximum temperature drop per 5 s: 5.2 ± 0.9°C, 3.9 ± 0.7°C, and 1.3 ± 0.7°C, P for trend <0.0001). CONCLUSION: The cooling effect of cryoballoon freezing is weaker in the deeper layers. Cryoballoon ablation should be performed with consideration to myocardial thickness.

Dual energy for pulmonary vein isolation using dual-energy focal ablation technology integrated with a three-dimensional mapping system: SmartfIRE 3-month results.

AIMS: Contact force (CF)-sensing radiofrequency (RF) catheters with an ablation index have shown reproducible outcomes for the treatment of atrial fibrillation (AF) in large multicentre studies. A dual-energy (DE) focal CF catheter to deliver RF and unipolar/biphasic pulsed field ablation (PFA), integrated with a three-dimensional (3D) mapping system, can provide operators with additional flexibility. The SmartfIRE study assessed the safety and efficacy of this novel technology for the treatment of drug-refractory, symptomatic paroxysmal AF. Results at 3 months post-ablation are presented here. METHODS AND RESULTS: Pulmonary vein isolation (PVI) was performed using a DE focal, irrigated CF-sensing catheter with the recommendation of PFA at posterior/inferior and RF ablation at the anterior/ridge/carina segments. Irrespective of energy, a tag size of 3 mm; an inter-tag distance ≤6 mm; a target index of 550 for anterior, roof, ridge, and carina; and a target index of 400 for posterior and inferior were recommended. Cavotricuspid isthmus ablation was permitted in patients with documented typical atrial flutter. The primary effectiveness endpoint was acute procedural success. The primary safety endpoint was the rate of primary adverse events (PAEs) within 7 days of the procedure. A prespecified patient subset underwent oesophageal endoscopy (EE; 72 h post-procedure), neurological assessment (NA; pre-procedure and discharge), and cardiac computed tomography (CT)/magnetic resonance angiogram (MRA) imaging (pre-procedure and 3 months post-procedure) for additional safety evaluation, and a mandatory remapping procedure (Day 75 ± 15) for PVI durability assessment. Of 149 patients enrolled between February and June 2023, 140 had the study catheter inserted (safety analysis set) and 137 had ablation energy delivered (per-protocol analysis set). The median (Q1/Q3) total procedure and fluoroscopy times were 108.0 (91.0/126.0) and 4.2 (2.3/7.7) min (n = 137). The acute procedural success rate was 100%. First-pass isolation was achieved in 89.1% of patients and 96.8% of veins. Cavotricuspid isthmus ablations were successfully performed in 12 patients [pulsed field (PF) only: 6, RF only: 5, and RF/PF: 1]. The PAE rate was 4.4% [6/137 patients; 2 pulmonary vein (PV) stenoses, 2 cardiac tamponades/perforations, 1 stroke, and 1 pericarditis]. No coronary artery spasm was reported. No oesophageal lesion was seen in the EE subset (0/31, 0%). In the NA subset (n = 30), microemboli lesions were identified in 2 patients (2/30, 6.7%), both of which were resolved at follow-up; only 1 was symptomatic (silent cerebral lesion, 3.3%). In the CT/MRA subset (n = 30), severe PV narrowing (of >70%) was detected in 2 patients (2/30, 6.7%; vein level 2/128, 1.6%), of whom 1 underwent dilatation and stenting and 1 was asymptomatic; both were associated with high index values and a small inter-tag distance. In the PV durability subset (n = 30), 100/115 treated PVs (87%) were durably isolated and 18/30 patients (60.0%) had all PVs durably isolated. CONCLUSION: A DE focal CF catheter with 3D mapping integration showed a 100% acute success rate with an acceptable safety profile in the treatment of paroxysmal AF. Prespecified 3-month remapping showed notable PVI durability. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05752487.

New-onset atrial fibrillation detected by ambulatory ECG monitoring after transcatheter aortic valve implantation.

BACKGROUND: Little is known about the occurrence of subclinical new-onset atrial fibrillation (NOAF) after transcatheter aortic valve implantation (TAVI). AIMS: We aimed to evaluate the incidence, predictors, and clinical impact of subclinical NOAF after TAVI. METHODS: This was a multicentre study, including patients with aortic stenosis (AS) and no previous atrial fibrillation undergoing TAVI, with continuous ambulatory electrocardiogram (AECG) monitoring after TAVI. RESULTS: A total of 700 patients (79±8 years, 49% female, Society of Thoracic Surgeons score 2.9% [1.9-4.0]) undergoing transarterial TAVI were included (85% balloon-expandable valves). AECG was started 1 (0-1) day after TAVI (monitoring time: 14121314 days). NOAF was detected in 49 patients (7%), with a median duration of 185 (43-421) minutes (atrial fibrillation burden of 0.7% [0.3-2.8]). Anticoagulation was started in 25 NOAF patients (51%). No differences were found in baseline or procedural characteristics, except for a higher AS severity in the NOAF group (peak gradient: no NOAF: 71.9±23.5 mmHg vs NOAF: 85.2±23.8 mmHg; p=0.024; mean gradient: no NOAF: 44.4±14.7 mmHg vs NOAF: 53.8±16.8 mmHg; p=0.004). In the multivariable analysis, the baseline mean transaortic gradient was associated with a higher risk of NOAF after TAVI (odds ratio 1.04, 95% confidence interval: 1.01-1.06 for each mmHg; p=0.006). There were no differences between groups in all-cause mortality (no NOAF: 4.7% vs NOAF: 0%; p=0.122), stroke (no NOAF: 1.4% vs NOAF: 2.0%; p=0.723), or bleeding (no NOAF: 1.9% vs NOAF: 4.1%; p=0.288) from the 30-day to 1-year follow-up. CONCLUSIONS: NOAF detected with AECG occurred in 7% of TAVI recipients and was associated with a higher AS severity. NOAF detection determined the start of anticoagulation therapy in about half of the patients, and it was not associated with an increased risk of clinical events at 1-year follow-up.

Impact of left atrial appendage flow velocity on thrombus resolution and clinical outcomes in patients with atrial fibrillation and silent left atrial thrombi: insights from the LAT study.

AIMS: Blood stasis is crucial in developing left atrial (LA) thrombi. LA appendage peak flow velocity (LAAFV) is a quantitative parameter for estimating thromboembolic risk. However, its impact on LA thrombus resolution and clinical outcomes remains unclear. METHODS AND RESULTS: The LAT study was a multicentre observational study investigating patients with atrial fibrillation (AF) and silent LA thrombi detected by transoesophageal echocardiography (TEE). Among 17 436 TEE procedures for patients with AF, 297 patients (1.7%) had silent LA thrombi. Excluding patients without follow-up examinations, we enrolled 169 whose baseline LAAFV was available. Oral anticoagulation use increased from 85.7% at baseline to 97.0% at the final follow-up (P < 0.001). During 1 year, LA thrombus resolution was confirmed in 130 (76.9%) patients within 76 (34-138) days. Conversely, 26 had residual LA thrombi, 8 had thromboembolisms, and 5 required surgical removal. These patients with failed thrombus resolution had lower baseline LAAFV than those with successful resolution (18.0 [15.8-22.0] vs. 22.2 [17.0-35.0], P = 0.003). Despite limited predictive power (area under the curve, 0.659; P = 0.001), LAAFV ≤ 20.0 cm/s (best cut-off) significantly predicted failed LA thrombus resolution, even after adjusting for potential confounders (odds ratio, 2.72; 95% confidence interval, 1.22-6.09; P = 0.015). The incidence of adverse outcomes including ischaemic stroke/systemic embolism, major bleeding, or all-cause death was significantly higher in patients with reduced LAAFV than in those with preserved LAAFV (28.4% vs. 11.6%, log-rank P = 0.005). CONCLUSION: Failed LA thrombus resolution was not rare in patients with AF and silent LA thrombi. Reduced LAAFV was associated with failed LA thrombus resolution and adverse clinical outcomes.

Atrial fibrillation increases thrombogenicity of LVAD therapy.

BACKGROUND: This study investigates the hypothesis that presence of atrial fibrillation (AF) in LVAD patients increases thrombogenicity in the left ventricle (LV) and exacerbates stroke risk. METHODS: Using an anatomical LV model implanted with an LVAD inflow cannula, we analyze thrombogenic risk and blood flow patterns in either AF or sinus rhythm (SR) using unsteady computational fluid dynamics (CFD). To analyze platelet activation and thrombogenesis in the LV, hundreds of thousands of platelets are individually tracked to quantify platelet residence time (RT) and shear stress accumulation history (SH). RESULTS: The irregular and chaotic mitral inflow associated with AF results in markedly different intraventricular flow patterns, with profoundly negative impact on blood flow-induced stimuli experienced by platelets as they traverse the LV. Twice as many platelets accumulated very high SH in the LVAD + AF case, resulting in a 36% increase in thrombogenic potential score, relative to the LVAD + SR case. CONCLUSIONS: This supports the hypothesis that AF results in unfavorable blood flow patterns in the LV adding to an increased stroke risk for LVAD + AF patients. Quantification of thrombogenic risk associated with AF for LVAD patients may help guide clinical decision-making on interventions to mitigate the increased risk of thromboembolic events.