Atrial Size Research Articles

Epicardial adipose tissue and subclinical incident atrial fibrillation in a population at risk of stroke - a cardiac magnetic resonance imaging study

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Innovation Fund Denmark. Background Atrial fibrillation (AF) is the most common cardiac arrhythmia worldwide and is associated with a substantially increased risk of morbidity and mortality, including heart failure and stroke(1,2). Epicardial adipose tissue (EAT) is believed to provide both thermoregulation and mechanical protection to the heart and coronary arteries in healthy human beings(3,4), but the role of EAT in the development and severity of AF suggests deleterious effects of EAT. Since EAT shares blood circulation with the myocardium, it offers the opportunity for paracrine- and neuroendocrine signaling(5), which contributes to an arrhythmogenic- and pro-inflammatory state. Purpose While EAT assessed by cardiac magnetic resonance imaging (CMR) has been found predictive of clinical AF(5,6), the association with subclinical AF has not yet been established. This study aimed to investigate the association between EAT, determined by CMR, and incident AF following long-term continuous heart rhythm monitoring by implantable loop recorder (ILR) in an at-risk population. Methods This study is a sub-study of the LOOP study. In total, 203 participants without a history of AF received an ILR and underwent advanced CMR. All participants were at least 70 years of age at inclusion and had at least one of the following conditions: hypertension, diabetes, previous stroke, or heart failure. Volumetric measurements of atrial- and ventricular EAT were derived from CMR, as seen in Picture 1, and the time to incident AF was subsequently determined. Results A total of 78 patients (38%) were diagnosed with AF during a median of 40 (37–42) months of monitoring. Of these, only 7 (9%) participants reported symptoms of AF during arrhythmia episodes, i.e., 91% had subclinical AF. In multivariate Cox regression analyses adjusted for age, sex, body mass index (BMI), and comorbidities, we found EAT to be an independent marker for time to AF with hazard ratios (95% confidence intervals) up to 1.66 (1.17–2.36; p = 0.005) when analyzing the risk of new-onset AF episodes lasting ≥ 24 hours. The Cox regression analyses are presented in Picture 2, where we furthermore have adjusted for left atrial size (LAMIN) and left atrial function (LATEF). Conclusion Atrial EAT assessed by volumetric measurements on CMR images was significantly associated with the incident AF episodes as detected by ILR.

Relationship Between Transthoracic Echocardiography and Transesophageal Echocardiography in the Anatomic and Hemodynamic Assessment of Secundum Atrial Septal Defects in Children and Adults

Objective: To determine the relationship between transthoracic and transesophageal echocardiography in the anatomic and hemodynamic assessment of secundum atrial septal defects in children and adults.
 Study Design: Cross-sectional study.
 Place and Duration of Study: Department of Paediatric Cardiology, National Institute of Cardiovascular Diseases, Karachi Pakistan, from Jul 2020 to Jun 2021.
 Methodology: Seventy-seven patients above three years of age with secundum atrial septal defects were included. Linear regression was used to determine any statistically significant difference between transthoracic and transesophageal echocardiography approaches.
 Results: Of 77 patients, there were 37(48.1%) male and 40(51.9%) female. No significant difference was noted in terms of any of the clinical parameters during transthoracic echocardiography and transesophageal echocardiography. As per transthoracic echocardiography, 35(45.5%) were noted to be deviceable, while in transesophageal echocardiography, 36(46.8%) patients were found to be deviceable (p=0.872). No emergency exploration or deaths occurred. Linear regression showed no statistically significant difference between transthoracic echocardiogram and transesophageal echocardiography findings in terms of atrial septal defects size (p=0.226), total septal length (p=0.930), RV systolic pressure (p=0.440), RV functions and TAPSE (0.748) except LV ejection fraction function findings (p<0.001).
 Conclusion: Anatomic and hemodynamic assessment of secundum atrial septal defects in children and adults correlated well with transthoracic and transesophageal echocardiography.

The Complex but Fascinating Relationship between Sport and Atrial Fibrillation: From Pathophysiology to the Clinical Scenario

Atrial fibrillation (AF) is the most common cause of hospital admission among all arrhythmias in the general population. Moreover, AF represents the most common arrhythmia in the athletic population as well. The complex but fascinating relationship between sport and atrial fibrillation has not yet been fully clarified. Although the benefits of moderate physical activity in controlling cardiovascular risk factors and in reducing the risk of atrial fibrillation have been widely demonstrated, some concerns have been raised about the potential adverse effects of physical activity. Endurance activity in middle-aged men athletes appears to increase the risk of AF. Several different physiopathological mechanisms may explain the increased risk of AF in endurance athletes, including the imbalance of the autonomic nervous system, changes in left atrial size and function and presence of atrial fibrosis. The goal of this article is to review the epidemiology, pathophysiology and clinical management for AF in athletes, including pharmacological and electrophysiological strategies.

Prevalence of pulmonary hypertension in mitral regurgitation and its influence on outcomes

ObjectivePulmonary hypertension (PHT) commonly coexists with significant mitral regurgitation (MR), but its prevalence and prognostic importance have not been well characterised. In a large cohort of adults with moderate or...

RENIN-ANGIOTENSIN-ALDOSTERONE BLOCKADE AND ITS PREDICTION OF LATE RECURENCE OF ATRIAL FIBRILLATION AFTER RADIOFREQUENCY ABLATION

Objective: Hypertension is one of the main triggers of atrial fibrillation. Patients with hypertension have 1.7 times higher risk of developing atrial fibrillation. Opinions differ on the use of RAAS blockers in atrial fibrillation. The aim is to evaluate the effect of RAAS blockers in the prevention of atrial fibrillation on the post-ablation prognosis of the patient. Design and method: A retrospective analysis of 221 patients who underwent radiofrequency ablation of atrial fibrillation at the First Department of Internal Medicine - Cardioangiology of St. Anne's University Hospital in Brno from 1 January to 31 December 2019 was performed. Recurrence within the first three months was designated as early, and in the following months as late. Results: The median age of the study population (N = 221) was 63 years, with 67.4% of men. According to pre-ablation transesophageal echocardiography, the mean left atrial dimension was 45.3mm and left ventricular ejection fraction was 59.8%. Among the comorbidities, hypertension (63.3%) and dyslipidaemia (41.6%) were the most common, followed by diabetes mellitus (14.0%), ischemic heart disease (7.2%), history of stroke (6.3%), chronic obstructive pulmonary disease (5.0%). 33.0% had a history of nicotinism. Among the baseline antihypertensive groups, beta-blockers were the most represented (69.2%) followed by angiotensin-converting enzyme inhibitors (37.5), angiotensin-receptor blockers (20.4%), calcium channel blockers (32.1%) and diuretics (32.1%). There was not a significant difference in the representation of each group of antihypertensives between the populations. n the group of patients treated with ACEis/ARBs (57.9%), the mean blood pressure resulting from pre- and post-ablation measurements was the same 149/81mm Hg. No significant differences in left atrial size or capture of early or late postablation recurrence (HR 1.26, 95% CI 0.84-1.90, p = 0.265) were detected in the RAAS inhibitor group relative to patients without ACEis/ARBs in therapy. Conclusions: Conventionally administered ACEis/ARBs before ablation procedure did not lead to a reduction in the detection of late postablation recurrence of atrial fibrillation. Despite the documented benefit of RAAS blocker therapy in atrial fibrillation patients, their routine administration before ablation procedure aimed at improving postablation prognosis was not evaluated as justified.

ATRIAL FIBRILLATION AND LEFT VENTRICLE SYSTOLIC FUNCTION IN MODERATE HYPERTENSIVE PATIENTS WHO COME TO THE EMERGENCY ROOM DUE TO INADEQUATE CONTROL OF BLOOD PRESSURE

Objective: To determine the percentage of cases of atrial fibrillation (AF) and left ventricular systolic function (LVEF) documented in hypertensive patients (PH) who come to the emergency room due to poor blood pressure control and those who do not attend. Design and method: From July 2020 to July 2021, we have studied 100 patients with hypertension, 60 women and 40 men with an average age of 72±8 years, who have previously been diagnosed and treated for hypertension. Of these PH, 22 had gone to the emergency room due to poor control of the BP. All underwent a standard echocardiogram and ABPM within 6 months of being seen in consultation with the cardiology specialist. The following parameters were measured: systolic and diastolic blood pressure (TAS, TAD), left ventricle systolic function (LVEF), left atrial size (LA) -The results were compared between those who went to the Emergency Department (PHER) and those who did not attend (PH) and we showed them. Results: TABLE: Conclusions: The PH that come to the Emergency Department have higher blood pressures and a higher frequency of atrial fibrillation, although the LVEF does not present significant differences. The size of the LA is also larger in the worst controlled patients, which indicates that we should follow this PH group more closely because of the important risk they have.

Atrial Fibrillation in Endurance Training Athletes: Scoping Review.

Moderate regular physical activity is indicated to avoid atrial fibrillation (AF), whereas athletes should be counseled that long-lasting vigorous sports engagement may cause AF, according to the 2016 European Society of Cardiology (ESC) recommendations for AF treatment. Exercise and AF are complex. To evaluate the relationship between Endurance training and AF, in addition to the starting point/trigger by which Endurance Training causes impairment of cardiac function and AF, considering the time and intensity of Endurance training. We synthesized evidence from articles published in the PubMed, EMBASE, and SciELO databases using their respective Boolean operators. A total of 112 original articles related to AF and endurance athletes published up to the year 2023 were reviewed. Our study verified multiples aspects of the genesis of AF in athletes, such as cardiac adaptations to exercise, disturbances in cardiac injury biomarkers, sex differences in cardiac adaptations and their role in AF risk, and the relationship between body composition (height, weight, and physical fitness) and AF pathogenesis. Variations in cardiac structure (increased atrial thickness and size in addition to myocardial fibrosis) and significant increases in vagal tone (sinus bradycardia and imbalances in sympathetic and parasympathetic activation) shorten the refractory period shortening in athletes, induce the onset of re-entrance mechanisms, and serve as ectopic triggers that can lead to AF.

Catheter ablation of atrial fibrillation versus antiarrhythmic therapy in patients with left ventricular systolic dysfunction

Aim. To evaluate the efficacy of catheter ablation (CA) of atrial fibrillation (AF) in patients with left ventricular systolic dysfunction and the effect of the procedure on the course of chronic heart failure (CHF) compared with the use of antiarrhythmic therapy (AAT). Materials and methods. The study included patients (n=80) with left ventricular ejection fraction (LVEF) less than 50% and AF, who were divided into 2 groups: the first group (n=40) underwent CA, the second group included patients on AAT. At baseline and after 6 months of follow-up, transthoracic echocardiography, determination of NT-proBNP concentration, 6-minute walk test and The Minnesota Living With Heart Failure Questionnaire were performed. Results. After 6 months of follow-up, the absence of documented AF paroxysms was observed in 80% in the CA group versus 45% in the AAT group (p=0,001). A significant increase in LV EF was revealed in both groups, however, in CA group it was more significant (57% [50,5; 60] in the CA group versus 46% [40; 50] in the AAT group (p=0,0001)). There was a decrease in the left ventricle ESD and the left atrial size and volume in the CA group, while in the AAT group the dynamics of these parameters did not change within six months (p=0.0001). An improvement in the clinical course of CHF was observed in both groups: the level of NT-proBNP was 196,6 [116,5; 327,1] pg/ml and 540.5 [382,8; 861,2] pg/ml (0,0001), the 6-minute walk distance increased to 470 m [400; 500] and 368 [330; 400] m (p=0,0001), respectively, the improvement of the functional class (1,15±0,67 and 2,05±0,55 (p=0,0001)) and the quality of life (p=0,0001) were observed. Conclusion . CA is an effective method for patients with AF and CHF. The use of CA in patients with CHF promotes reverse remodeling, a decrease in the level of NT-proBNP, as well as an improvement in the quality of life and an increase in exercise tolerance.

The novel left atrial anterior 'seatbelt' line reduces sustained atrial arrhythmia by 72% compared to pulmonary vein isolation alone in a cohort of 400 virtual atria models

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – EU funding. Main funding source(s): European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No.860974. Background The success-rate of pulmonary vein isolation (PVI) is modest in persistent atrial fibrillation (AF), but additional empirical ablation, such as posterior wall isolation (PWI), has not been shown to reduce the rate of AF recurrence. The "seatbelt", an anterior linear ablation lesion connecting the right superior pulmonary vein to the mitral annulus, is a novel substrate modification approach that is yet to be tested in a large-scale randomised clinical trial. Purpose To use in-silico trials with human-based modelling and simulation to compare the efficacy of (i) PVI alone, (ii) PVI and PWI (PVI+PWI), or (iii) PVI and seatbelt (PVI+SB) for the prevention of atrial arrhythmia in large populations of virtual patient models. Methods AF was simulated in a cohort of 400 virtual atrial models with anatomical and electrophysiological variability, with AF persisting for >7 seconds defined as sustained. Models which sustained AF were each independently subjected to all three ablation approaches before repeating the AF induction protocol. Results Three hundred forty-four (86%) atrial models developed sustained AF at baseline. After applying the ablation lesions, substantially fewer models sustained atrial arrhythmias in the PVI+SB group (50 [14%] vs. 134 [39%] with PVI+PWI vs. 172 [50%] with PVI). PVI+SB was more effective than PVI and PVI+PWI in preventing both AF and atrial flutter (i.e., presence of a single rotor), since PVI and PVI+PWI led to the formation of anatomical re-entries around the rings of the pulmonary veins and the posterior wall of the left atrium, respectively (Figure). Therefore, PVI+SB restricted atrial flutter mainly to the right atrium (either anatomical, around the inferior cava vein, or functional, meandering throughout the venous portion of the right atrium, Figure). Importantly, in all three ablation strategies, the likelihood of AF recurrence was directly proportional to the surface area of the right atrium (AF probability increased 0.95%/cm², 0.88%/cm² and 0.56%/cm² after PVI+SB, PVI+PWI and PVI, respectively). The role of the right atrial size was less accentuated for PVI alone, since after the ablation the entire left atrial body was still available for rotor anchoring. Moreover, an enlarged left atrium enabled the appearance of micro-re-entries in the anterior and inferior wall of the left atrium, even after applying floor and roof lines. One atrial model additionally presented a rotor in the posterior wall of the left atrium after completely isolating it from the left atrial body. Conclusion(s) In a cohort of 400 virtual atrial models, PVI+SB reduced sustained atrial arrhythmias by 72% compared to PVI alone and by 64% to PVI+PWI, but AF could still originate in an enlarged right atrium.

3D intracardiac echocardiography for left atrial appendage sizing and percutaneous occlusion guidance

Abstract Funding Acknowledgements Type of funding sources: None. Background Left atrial appendage (LAA) imaging is critical during percutaneous occlusion procedures. 3D-intracardiac echocardiography (ICE) features direct visualization of LAA from multiple cross-sectional planes at a time. Purpose To report procedural success of 3D-ICE-guided LAA occlusion and the correlation between pre-procedural transesophageal echocardiography (TEE) and intraprocedural 3D-ICE for LAA sizing. Methods Among 274 patients undergoing LAAO, periprocedural ICE guidance was achieved via a commercially available 2D-ICE catheter (220 patients) or a novel 3D-ICE one (54 patients; Fig.1). Primary endpoint was a composite of procedural success and LAA sealing at follow-up TEE. Secondary endpoint was a composite of periprocedural device recapture/resizing plus presence of leaks≥3mm at follow-up TEE. Results 3D-ICE measurements of maximum landing zone correlated highly with preprocedural TEE reference values [Pearson’s: 0.94; p<0.001; bias: -0.06 (-2.39, 2.27)] (Fig.2). The agreement between 3D-ICE-based device selection and final device size was 96.3% versus 79.1% with 2D-ICE (p=0.005). The incidence of the primary endpoint was 98.1% with 3D-ICE and 97.3% with 2D-ICE (p=0.99). 2D-ICE patients had a trend towards a higher incidence of periprocedural device recapture/redeployment (31.5% vs 44.5%; p=0.09). The secondary endpoint occurred in 31.5% of 3D-ICE patients versus 45.9% of 2D-ICE ones (p=0.065). Conclusions ICE-guided LAAO showed a very high success, with no major adverse events. A very high level of agreement for LAA sizing was found between pre-procedural TEE and periprocedural 3D-ICE. 3D-ICE performed significantly better than 2D-ICE for device size selection and may provide better guidance during device deployment.

Left atrial dyssynchrony in veteran athletes with paroxysmal atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): A Ph.D. grant from the DAM Foundation and a grant from the Raagholt foundation. Background Prolonged endurance exercise is associated with an increased risk of atrial fibrillation (AF) in men. Increased left atrial (LA) size is associated with AF in the general population. LA dilation in athletes is viewed mainly as a physiological response to exercise, and functional atrial parameters may help distinguish pathological from physiological atrial remodeling in this group. LA mechanical dispersion (LA MD) is a novel marker of LA mechanical dyssynchrony. It is yet to be evaluated whether LA MD could be a marker of pathological remodeling in veteran athletes. Purpose To describe LA MD measured by speckle tracking echocardiography in male veteran athletes who had regularly participated in the 54 kilometer cross-country (XC) ski race Birkebeinerrennet in Norway with and without AF, and men with and without AF from a background population. Methods In total, 295 men, veteran XC skiers with (n=57) and without (n=88) paroxysmal AF, and men from a non-athletic population with paroxysmal AF (n=62) and without AF (n=88) were examined with echocardiography while in sinus rhythm. LA MD was defined as the standard deviation of time to peak strain (SD-TPS) including all accepted atrial segments, and stated both in milliseconds, and corrected by the cycle length ((SD-TPS(ms)/Cycle length(ms))x100)). The average of three consecutive loops was computed. A two-way between-groups analysis of variance was performed to explore the main effects of AF status, athletic status, and the interaction between AF status and athletic status in LA echocardiographic parameters. Results XC skiers (mean age 70.9±5.7 years) reported an average of 40-50 years of regular endurance exercise and had completed an average of 17 annual Birkebeiner races. LA volumes were associated with both AF and athletic status. LA MD in milliseconds was associated with AF, but not associated with athletic status. Conclusion LA MD was associated with paroxysmal AF both in veteran endurance athletes and non-athletes, and less affected by athletic status than atrial volumes. This implies that LA MD could be a useful marker when trying to distinguish physiological from pathological atrial remodeling in endurance athletes.

Right atrial collision time (RACT): A novel marker of propensity for typical atrial flutter.

The risk of typical atrial flutter (AFL) is increased proportionately to right atrial (RA) size or right atrial scarring that results in reduced conduction velocity. These characteristics result in propagation of a flutter wave by ensuring the macro re-entrant wave front does not meet its refractory tail. The time taken to traverse the circuit would take account of both of these characteristics and may provide a novel marker of propensity to develop AFL. Our goal was to investigate right atrial collision time (RACT) as a marker of existing typical AFL. This single-centre, prospective study recruited consecutive typical AFL ablation patients that were in sinus rhythm. Controls were consecutive electrophysiology study patients >18 years of age. While pacing the coronary sinus (CS) ostium at 600 ms, a local activation time map was created to locate the latest collision point on the anterolateral right atrial wall. This RACT is a measure of conduction velocity and distance from CS to a collision point on the lateral right atrial wall. Ninety-eight patients were included in the analysis, 41 with atrial flutter and 57 controls. Patients with atrial flutter were older, 64.7 ± 9.7 versus 52.4 ± 16.8 years (<.001), and more often male (34/41 vs. 31/57 [.003]). The AFL group mean RACT (132.6 ± 17.3 ms) was significantly longer than that of controls (99.1 ± 11.6 ms) (p < .001). A RACT cut-off of 115.5 ms had a sensitivity and specificity of 92.7% and 93.0%, respectively for diagnosis of atrial flutter. A ROC curve indicated an AUC of 0.96 (95% CI: 0.93-1.0, p < .01). RACT is a novel and promising marker of propensity for typical AFL. This data will inform larger prospective studies.

Catheter ablation of left atrial tachyarrhythmia: predictors of recurrence after catheter ablation

Abstract Funding Acknowledgements Type of funding sources: None. Background Differently from catheter ablation (CA) of atrial fibrillation (AF), outcome data on CA of atrial re-entrant arrhythmias are scarce. Purpose We sought to evaluate predictors of recurrence at follow up in this setting. Methods We analysed consecutive patients undergoing mapping and CA left atrial tachyarrhythmia. Three-dimensional high-density activation and voltage maps were created for each investigated tachycardia by means of CARTO® system. Left atrial (LA) size was measured as the anteroposterior diameter on parasternal long axis view on transthoracic echocardiogram. Severe LA enlargement was defined for LA diameter &amp;gt;47 mm in women and &amp;gt;52 mm in men in accordance with guidelines. Results Eighty-eight patients were considered (67 ± 9 years old, 45% males) undergoing 94 CA procedures (1.1 ± 0.3 per patient). Most patient had past medical history of pulmonary vein isolation (57%). In the investigated population, 120 tachycardia morphologies were mapped and ablated. Acute procedural success was achieved in 97% of cases without any major complication. After a mean follow-up of 17 ± 11 months, the overall freedom from atrial arrhythmia was 58% and 65% after single and repeat procedures, respectively. Severe LA enlargement was the only variable associated with arrhythmia recurrence at follow-up and it was consistent after single and repeat procedures (Figure 1 A-B). Conclusion CA of complex left atrial tachyarrhythmia is safe and effective, and the mid- and long-term outcome is improved when LA is not severely enlarged. CA of should therefore be considered early in this patient population to achieve better clinical outcome.

Efficacy and safety of pulmonary vein isolation with irrigated radiofrequency balloon with a zero-fluoroscopy protocol

Abstract Funding Acknowledgements Type of funding sources: None. Introduction From the beginning, the use of X-ray (XR) has been a critical component in both the guidance and development of arrhythmia ablation procedures. Despite the development of non-fluoroscopic navigators, the single-shot techniques for atrial fibrillation ablation procedures still rely almost exclusively on the use of XR. Recently, the Heliostar® irrigated radiofrequency balloon has been developed, which can be completely visualized on the Carto 3® navigation system. This special feature makes it possible to minimise the use of XR in this type of procedure or even suppress it. We present our first experience after the implementation of a "zero-XR" protocol for this procedure. Objectives The aim of this study was to demonstrate that "zero-XR" ablation of atrial fibrillation with Heliostar® radiofrequency balloon is possible and safe. Methods This is a single-centre study. Consecutively 22 patients with paroxysmal (63.6%) or persistent (36.4%) atrial fibrillation underwent pulmonary vein isolation by irrigated radiofrequency balloon (Heliostar®). Eight of the cases were performed without fluoroscopy, supported by the navigation system and intracardiac ultrasound, and the remaining 14 were performed without limitation of the use of XR. Clinical, echocardiographic and technical data were collected from all 22 patients. All cases were performed under general anaesthesia, with the Carto 3® navigation system. Mapping was performed in sinus rhythm whenever possible. Results 100% isolation of the veins was achieved, with 62.1% first pass isolation in the non-XR group versus 56.4% in the XR group (non-significant difference). The vein with the highest percentage of first pass isolations was the left inferior vein in both groups. There were no complications in either group. Procedure times were similar (left atrial dwell time of 32 minutes in the non-XR group and 40 minutes in the XR group, non-significant difference), although the mapping time was slightly shorter in the non-XR group (9,9±5 non-XR vs 16±6.9, p=0.04). There was also no difference in the mean time to isolation from the start of radiofrequency application in each vein (10.6 seconds in the non-XR group and 11 seconds in the XR group, p=0.75). The non-XR group had a higher number of patients with left main trunk, but the XR group had a higher percentage of patients with persistent forms of atrial fibrillation. Left atrial size was normal in most patients, and ventricular function was preserved, with no differences between the two groups. Conclusion Pulmonary vein isolation with the Heliostar® radiofrequency balloon without XR is possible and safe, with similar efficacy and first pass isolation rate, similar procedure time and no relevant complications in our series.

Pulsed-field ablation versus single catheter high-power short-duration radiofrequency ablation for atrial fibrillation: procedural characteristics, myocardial injury and midterm outcomes

Abstract Funding Acknowledgements Type of funding sources: None. Background Pulsed-field ablation (PFA) has emerged as a novel treatment strategy for patients with atrial fibrillation (AF). A direct comparison to high-power short-duration (HPSD) radiofrequency (RF) ablation using a single catheter is lacking. Aim To compare pulmonary vein isolation (PVI) using PFA versus single catheter HPSD-RF ablation regarding efficiency, safety, myocardial injury, and outcomes. Methods 119 patients underwent PVI and were included (age 65.6 ± 10 years, ejection fraction 0.55 ± 0.11, left atrial size 41 ± 6.6 mm, paroxysmal AF 55%). 56 patients (47%) underwent PFA using a multi-electrode pentaspline PFA catheter with a biphasic waveform and 63 patients (53%) underwent single catheter HPSD-RF ablation without a multipolar mapping catheter. Results Using PFA the median procedure time was significantly shorter compared to the single catheter HPSD-RF group with 58 (IQR 51-70) min versus 83 (IQR 71-99) min (p&amp;lt;0.001), while fluoroscopic time was significantly longer with 12 (IQR 10-16) min versus 2.2 (IQR 1.3-3.6) min (p&amp;lt;0.001). First-pass isolation was achieved in 91% of the PFA group and 88% in the HPSD-RF group. 3.3 catheters vs. 1.0 catheters were used in the PFA group versus the HPSD-RF group, p&amp;lt;0.01. One procedural complications was observed in the PFA group and one complication in the HPSD-RF group (Tamponades). High sensitivity cardiac troponin levels were on average significantly higher in patients using the PFA system, 1520 (IQR 1010-1980) ng/l compared to 897 (IQR 725-1240) ng/l in the HPSD-RF group. During a median follow-up of 177 days (IQR 92-300), AF recurrence was observed in five patients (9%) from the PFA group and in 15 patients (24%) from the HPSD-RF group. (Figure 1) Conclusion PFA showed shorter procedure times but longer fluoroscopy times, higher levels of hs cTnT, and a possible improved AF-free survival.

Local conduction velocities determined by non-invasive electrocardiographic imaging predict arrhythmia-free survival after pulmonary vein isolation

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – EU funding. Main funding source(s): This project has received funding from the European Union's Horizon Research and Innovation Programme under the Marie-Sklodowska Curie Grant Agreement No. 860974 Background Recurrence rates after atrial fibrillation (AF) ablation are still unsatisfactory. As catheter ablation is primarily targeting pulmonary vein (PV) ectopic activity, it is not surprising that extra-PV arrythmogenic substrate is a key determinant of arrhythmia recurrence. Against this background, several studies have proposed assessment of extra-PV substrate in terms of atrial fibrosis or locally reduced conduction velocities (CV) to guide treatment. However, to date no non-invasive method directly assessing electrical arrhythmogenic substrate has been established in clinical practice, and treatment decisions are commonly based on crude surrogates like AF type or left atrial size. Here we establish and validate a novel non-invasive method based on electrocardiographic imaging (ECGi) to determine atrial arrhythmogenic substrate in terms of reduced local CVs and its predictive value regarding arrhythmia recurrence after PVI. Methods and results 52 consecutive patients scheduled for AF ablation (PVI-only) and 19 healthy controls were prospectively included and received ECGi to assess left and right atrial arrhythmogenic substrate. This ECGi-based method uses 64 electrodes placed on the torso. Subsequently, a 3D model of the torso is acquired as an anatomical reference using a 3D reconstruction camera. A personalised 3D atrial geometry is then derived from a database of human atria using an artificial intelligence-based algorithm. Finally, unipolar surface electrograms are projected onto the cardiac geometry and local CVs are estimated. Mean ECGi-determined atrial CVs were significantly lower in AF patients than in healthy controls, both in a global analysis (1.45±0.15 m/s vs. 1.64±0.15 m/s; p&amp;lt;0.0001) and a regional analysis of 19 predefined left and right atrial segments (Fig. 1). Considering only the segments with the lowest average CV in each patient, differences in CVs were more pronounced (0.80±0.22 vs. 1.08±0.26 m/s; p&amp;lt;0.0001). Multivariate logistic regression analyses combined with c-statistics including other previously proposed predictors found this mean CV of the "slowest" segment to be the strongest predictor of arrhythmia recurrence. A ROC analysis revealed that a cut-off for this variable of 0.72 m/s best discriminates PVI responders from non-responders: patients with a mean CV &amp;gt;0.72 m/s in all atrial regions showed a 6-months arrhythmia-free survival of 90.9%, whereas patients with one or more atrial regions with a mean CV &amp;lt;0.72 m/s had a poor outcome with an arrhythmia-free survival rate of only 57.9% (Fig. 2). Conclusion This was the first study to investigate local atrial CV non-invasively and to validate their predictive value regarding outcome after PVI. The absence of ECGi-determined areas of slow conduction well discriminated PVI responders from non-responders. Such non-invasive assessment of electrical arrhythmogenic substrate may guide treatment strategies and be an important step towards personalised AF therapy.

The role of biomarkers, sleep apnea and echocardiography as predictors of atrial fibrillation in a pacemaker population

Abstract Funding Acknowledgements Type of funding sources: None. Background Sleep apnea, dilated left atrial has been related to a higher possibility to develop atrial fibrillation (AF). Some pacemakers are able to detect periods of apnea during the sleeping time obtaining a respiratory disturbance index (RDI) related to sleep apnea (SA), as well as atrial high rate episodes (AHREs) that are also predictors of AF. Another possible predictor of AF is galectin-3, a biomarker related to fibrotic phenomena. This study aims to evaluate the relationship between ARI and AHRE detection, as well as the relationship between left atrial size measured by echocardiography and some biomarkers with the development of AHREs. Methods This is a single-centre, prospective, non-randomized, descriptive study carried out in a tertiary hospital, including patients with dual-chamber pacemaker able to detect SA, initially in sinus rhythm. Patients were included at the implantation date, between November 2015 and November 2018, and medium follow-up was 2 years. Those with a previous diagnosis of AF were not included. In a baseline visit, clinical, anthropometric characteristics, as well as echocardiography and analytical parameters were obtained, including NTproBNP, galectin-3 and ST-2. In addition to the baseline visit, device interrogation visits at six months, one year and tho years in order to obtain atrial activity and SA registers were performed. Those whose apnea recordings were illegible were excluded from the analysis. We performed a descriptive statistical analysis with Microsoft Excel. Results 102 patients with dual chamber pacemaker were included. 79 of the pacemakers provided legible apnea and atrial activity recordings. 22 of them showed an RDI&amp;gt;20 in more than 75% of the nights, and 38 of them recorded AHRE longer than 6 minutes in 24 hours. Tables 1 and 2 show baseline characteristics and the AHRE (episodes with duration &amp;gt;6 minutes) and RDI recordings suggestive of severe SA (RDI&amp;gt;20 in more than 75% of the nights). Differences in AHRE between both RDI groups did not reach statistical significance. After univariate analysis, the multivariate analysis showed significant relationship between AHRE &amp;gt;6 minutes and the galectin-3 level at baseline as well as between AHRE&amp;gt;6 minutes and the left atrial indexed volume at baseline. Conclusion In our study, 48% of the pacemakers registered AHRE longer than 6 minutes in 24 hours. No statistical relationship between RDI and AHRE was found. Baseline galectin-3 level and left atrial indexed volume appeared to be related to the development of AHRE in the follow-up.

Early timing of ablation after diagnosis: a powerful way to reduce atrial fibrillation recurrence

Abstract Funding Acknowledgements Type of funding sources: None. Background Diagnosis-to-ablation time (DAT) is a strong, modifiable predictor of AF recurrence after ablation. Referral time for ablation, and hence DAT became shorter over time. Purpose To search for the shortest DAT still impacting outcome and to look at the evolution of the "DAT-AF recurrence" relation over time in a wide range of DAT. Methods and results Two cohorts of 1000 AF patients (69% males, age 62±10 years) undergoing PVI (2006-2014 and 2017-2019) were followed for 3years. Clinical success, defined as freedom of documented AF was achieved in 61,7% of patients. Independent predictors of clinical success were age (HR=1,01; 95%CI 1,01-1,02; p 0,003), AF type (HR=0.54; 95%CI 0.46-0.63; p&amp;lt;0.0001), left atrial size (HR=1.05; 95%CI 1.03-1.06; p&amp;lt;0.0001), DAT (HR=1.00; 95%CI 1.00-1.00; p=0.001) and ablation technique (p=0.01) in multivariable-adjusted analysis. DAT decreased over time from 48±47 to 35±60months (p=0,001). Relation between the DAT (range 0-288months) and AF recurrence at 3 years was assessed in 1892 patients. The adjusted AF recurrence rate rises steeply from 27 to 40% in the first 36months. With further lengthening of the DAT the curve flattens following a less steep rise up to 45% until 90months. Further flattening occurs after a DAT of 90months. Conclusion The AF recurrence rate starts to rise immediately after diagnosis and demonstrates a linear relation over time with increasing DAT times, most pronounced in the first 3 years after diagnosis and flattening thereafter. Our data advocate for ‘as early as possible’ PVI planning following diagnosis of AF to improve outcome.

ADONHERS (Aged DONor HEart Rescue by Stress Echo) National Protocol: Recipient's Survival after 10-Year Follow-Up.

Background: The gold-standard treatment for end-stage heart failure is heart transplantation, but the lack of organ donors remains an important limitation in this field. An accurate selection of marginal hearts is fundamental to increase organ availability. Purpose: In our study we analyzed if recipients receiving marginal donor (MD) hearts, selected by dipyridamole stress echocardiography according to the ADOHERS national protocol, had different outcomes compared to recipients with acceptable donor (AD) hearts. Methods: Data were collected and retrospectively analyzed from patients who received an orthotopic heart transplant at our institution between 2006 and 2014. Dipyridamole stress echo was performed on identified marginal donors and selected hearts were eventually transplanted. Clinical, laboratory and instrumental features of the recipients were evaluated and patients with homogenous baseline characteristics were selected. Results: Eleven recipients transplanted with a selected marginal heart and eleven recipients transplanted with an acceptable heart were included. Mean donor age was 41 ± 23. The median follow-up was 113 months (IQR 86-146 months). Age, cardiovascular risk and morpho-functional characteristics of the left ventricle were comparable between the two populations (p > 0.05). Left atrial size was significantly higher in patients with marginal hearts (acceptable atrial volume: 23 ± 5 mL; marginal atrial volume: 38 ± 5 mL; p = 0.003). Acceptable donor recipients showed a higher impact of Cardiac Allograph Vasculopathy (p = 0.019). No rejection differences were found between the two groups. Four patients deceased, three were standard donor recipients and one was from the marginal donor group. Conclusions: Our study shows how cardiac transplant (Htx) from selected marginal donor hearts through a non-invasive bedside technique can alleviate the shortage of organs without a difference in survival compared to acceptable donor hearts.

Hippocampal rotation is associated with ventricular atrial size.

Fetal ventriculomegaly is a source of apprehension for expectant parents and may present prognostic uncertainty for physicians. Accurate prenatal counseling requires knowledge of its cause and associated findings as the differential diagnosis is broad. We have observed an association between ventriculomegaly and incomplete hippocampal inversion. To determine whether ventricular size is related to incomplete hippocampal inversion. We retrospectively evaluated pre- and postnatal brain MRIs in normal subjects (mean GA, 31weeks; mean postnatal age, 27days) and patients with isolated ventriculomegaly (mean GA, 31weeks; mean postnatal age, 68days) at a single academic medical center. Lateral ventricular diameter, multiple qualitative and quantitative markers of hippocampal inversion, and evidence of intraventricular hemorrhage were documented. Incomplete hippocampal inversion and ventricular size were associated in both normal subjects (n=51) and patients with ventriculomegaly (n=32) (P<0.05). Severe ventriculomegaly was significantly associated with adverse clinical outcome in postnatal (P=0.02) but not prenatal (P=0.43) groups. In all additional cases of isolated ventriculomegaly, clinical outcome was normal over the time of assessment (mean 1±1.9years; range 0.01 to 10years). Lateral ventricular atrial diameter and incomplete hippocampal inversion are associated. Less hippocampal inversion correlates with larger atria. For every 1-mm increase in fetal ventricular size, the odds of incomplete hippocampal inversion occurring increases by a factor of 1.6 in normal controls and 1.4 in patients with ventriculomegaly.