Sinus Rhythm Atrial Fibrillation Research Articles

Peak frequency can be effectively used to characterize atrial remodelling in atrial fibrillation

Abstract Introduction Characterizing atrial fibrillation (AF) substrate can guide ablation strategies, particularly as current efficacy leaves room for substantial improvement. Low voltage zones (LVZs) correlate with atrial fibrosis and scar and can independently predict AF recurrence. Ablation of these zones improves freedom from arrhythmia, but the chaotic nature of atrial excitation frequently results in overestimation of LVZs limiting accurate substrate identification. Purpose While omnipolar voltage (OV) mapping has emerged to address this issue by closely correlating with sinus rhythm (SR) voltage maps, our study builds upon this by investigating a novel parameter, peak frequency (PF), to further refine AF substrate characterization. Methods Patients undergoing catheter ablation for persistent AF were enrolled. OV maps and PF maps were created during AF while bipolar voltage (BV) maps were created in SR with atrial pacing at pacing intervals (PIs) of 600ms and 250ms. Areas were classified as fixed scar (consistent LVZs across all maps), functional remodelling (LVZs in AF OV and SR BV 250ms maps) and non-LVZs (normal voltage across all maps). PF was assessed in these areas and defined as the highest frequency detected in the electrogram. Results Among 20 patients, the average voltage in AF OV maps differed significantly from SR BV 600ms (0.49±0.76mV in AF OV vs. 1.12±0.97mV SR BV 600ms, p<0.001) but not SR BV 250ms maps (0.49±0.76mV in AF OV vs. 0.52±0.84mV SR BV 250ms, p=0.10). Comparing co-registered points, there was a significant difference between AF OV and SR BV 600ms maps (0.21±0.09mV, p<0.001) but not between AF OV and SR BV 250ms maps (0.06±0.04mV, p=0.10). These findings were also consistent with regards to the proportion of LA area occupied by LVZs (42.4±8.2% AF OV, 24.3±7.4% SR BV 600ms and 39.4±6.7% SR BV 250ms; p=0.001). AF OV maps thereby correlated better with SR BV 250ms maps hence representing both fixed scar and functional remodelling. PF values ≥244Hz were predictive of non-LVZs (OR 3.91, 95% CI 3.77-4.07,) with an AUC of 0.71. A PF of ≤214Hz was predictive of fixed scar (OR 17.67, 95% CI 16.82-18.56, p<0.001) with an AUC of 0.90. A PF between 215-236Hz was predictive of functional remodelling (OR 2.83, 95% CI 2.71-2.95, p<0.001) with an AUC of 0.60. The majority of LVZs identified exclusively in AF OV maps exhibited PFs akin to those in non-LVZs highlighting the ability of PF to pinpoint potential overestimations in LVZs. Conclusions PF mapping can effectively discern between areas of fixed scar, functional remodelling, and potential overestimation of LVZs. PF may enhance substrate characterization in AF utilising data solely from electrograms.Trial Design and Zone AssignmentPeak Frequency and Voltage Zones

NT-proBNP in severe aortic valve stenosis: necessity for higher cut-off values regarding congestive heart failure detection in atrial fibrillation

Abstract Background NT-proBNP is an established biomarker for the determination of fluid overload. Patients suffering from atrial fibrillation seem to have higher serum levels of NT-proBNP than patients in sinus rhythm, independent from fluid overload. However, there is no established alternative cut-off for patients with atrial fibrillation, especially in patients with severe aortic valve stenosis. Aim The aim of the current study was to evaluate the levels of serum NT-proBNP for patients with atrial fibrillation (AF) and sinus rhythm (SR) for the determination of fluid overload in patients with severe aortic valve stenosis. Methods 167 Patient suffering from severe aortic valve stenosis undergoing evaluation for TAVR at our hospital were included in this study. Upon recruitment blood samples from every patient were collected and an ECG was documented for each patient. Serum NT-proBNP was measured and volume overload was objectivated by calculation of plasma volume status (PVS), an already published method to estimate fluid overload or depletion by using a formula including weight and haematocrit. Results 37 patients (22.2%) suffered from AF upon recruitment. 47 patients (28.1%) showed fluid overload, indicated by increased PVS (PVS > 0, SR n=37, AF n=10). 94 patients (56.3%) were male and mean age was 80 years. Patients with and without AF showed no significant difference in age, sex or prevalence of cardiovascular diseases, except for gradients across the aortic valve (SR 47mmHg vs. AF 38mmHg; p<0.05) and left ventricular ejection fractions (SR 57% vs. AF 55%; p<0.05). Patients suffering from atrial fibrillation showed significantly higher serum levels of NT-proBNP (4843 ng/L vs. 1226 ng/L, p<0.001). ROC-analyses in patients with SR and severe aortic valve stenosis, showed satisfying results for NT-proBNP (AUC 0.72; sensitivity 0.81; specificity 0.58) to detect fluid overload. Comparable results were evident in patients with AF (AUC 0.77; sensitivity 0.70; specificity 0.78), but cut-off-values in patients suffering from atrial fibrillation were more than six times as much as in patients with sinus rhythm (6575 ng/L vs. 1053 ng/L). Conclusion NT-proBNP proved itself as a sufficient marker to determine volume overload in patients with severe aortic valve stenosis. Cut-offs for accurate determination of fluid overload deviate greatly in patients with sinus rhythm and atrial fibrillation, therefore different cut-offs might be required.

Soluble ST2 and its relation to inflammatory, vascular atherosclerotic, and calcification markers in patients with atrial fibrillation or heart failure at moderate-to-high cardiovascular risk

Background: Cardiovascular diseases (CVDs) are the major cause of death globally. Among them, heart failure (HF) and atrial fibrillation (AF) result in poor prognosis and quality of life. Standard methods for assessing AF and HF, through history and physical examination, have limited sensitivity and specificity, which lead to delayed diagnosis and high risk of mortality. The identification of biomarkers able to detect the early stages of disease and/or their progression is of great importance for improving the clinical outcome. As AF and HF often coexist, it would be of great importance to find a biomarker with diagnostic utility in predicting HF in AF patients. Soluble suppression of tumorigenesis-2 (sST2) is a part of the cardioprotective IL-33/ST2 signaling pathway and may serve as a candidate biomarker for HF and AF. We aimed to evaluate sST2 serum levels in patients with AF and HF with preserved ejection fraction (HFpEF) and to explore potential relationships with traditional CVD risk factors and with novel biomarkers for vascular calcification such as undercarboxylated matrix Gla-protein (ucMGP). Materials and Methods: This study included 99 patients stratified into three groups: HFpEF (n=19), paroxysmal or persistent AF in sinus rhythm (n=33), and control group without CVD but at moderate-to-high CVD risk (n=47). Hemodynamic and anthropometric measures, coronary artery calcification (CAC), routine laboratory parameters, circulating ucMGP, and sST2 were measured. Results: sST2 levels were highly elevated in HFpEF patients. Significant positive correlation was found between sST2 and CAC-score (r=0.237, p=0.039), negative relations with serum lipids in AF patients, and positive association with serum C-reactive protein (r=0.609, p=0.018) in HFpEF patients. Soluble ST2 positively correlates with ucMGP in the entire studied population (r=0.252, p=0.006) and in the combined CVD group (AF+HFpEF) (r=0.254, p=0.036). Conclusions: sST2 levels emerge as a novel biomarker in CVD and may have prognostic importance for HF prediction in AF patients.

Usefulness of risk scores and predictors of atrial fibrillation recurrence after elective electrical cardioversion.

Electrical cardioversion (ECV) is a frequently used procedure for restoring sinus rhythm in atrial fibrillation (AF); however, the rate of recurrence is high. The identification of patients at high risk of recurrence could influence the decision-making process. The present study evaluates the predictive value of risk scores in atrial fibrillation recurrence after elective electrical cardioversion. Unicentric, observational, and prospective study of adult patients who have undergone an elective ECV as rhythm control strategy between July 2017 and September 2022. From the 283 analyzed patients (mean age 63.95 ± 10.76212, 74.9% male); 99 had paroxysmal AF (35%) and 159 (59%) presented AF recurrence during a follow-up of 6 months. In patients with post-ECV AF recurrence, the period of time from diagnosis until the performance of the procedure was longer (393 ± 891 vs. 195 ± 527, p = .02). No paroxysmal AF (71.3% vs. 57.8%, p = .02) and LA dilatation with >40 mL/m2 (35.9% vs. 23.3%, p = .02) volumes were more frequent within these patients. AF recurrence was more frequent in patients who had previous ECV (HR = 1.32; 95% CI: 1.12-2.35; p = .01) and more than 1 shock to recover sinus rhythm (HR = 1.62; 95% CI: 1.07-1.63; p = .01). The SLAC, ALARMEc, ATLAS, and CAAP-AF scores were statistically significant, although with a moderate predictive capacity for post-ECV recurrence. Risk scores analyzed showed a modest value predicting AF recurrence after ECV. Previous ECV, and greater difficulty in restoring SR were independent predictors of recurrence.

Abstract 14165: Left Atrial Appendage Emptying Velocity as a Predictor of Energy Required for Successful DC Cardioversion in Patients With Atrial Fibrillation

Background: Atrial fibrillation (AF) is a prevalent cardiovascular disease in the elderly population. Restoring sinus rhythm in AF often involves antiarrhythmic drugs, direct current (DC) cardioversion, and ablation. The predictive value of left atrial appendage (LAA) emptying velocity in determining the energy required for successful DC cardioversion remains uncertain. Aim: To study the association between LAA emptying velocity and the amount of energy required for cardioversion in patients with AF undergoing DC cardioversion. Methods: A total of 79 consecutive AF patients were enrolled in the study. Transesophageal echocardiography was performed to exclude the presence of clot formation, after which patients underwent DC cardioversion using escalating biphasic energy levels of 100 joules, 200 joules, and 360 joules to restore sinus rhythm. Patients were stratified into two groups based on LAA emptying velocity: the low-velocity group (≤30 cm/sec) and the high-velocity group (>30 cm/sec). Clinical characteristics were compared between the groups. Results: Of the 79 patients, 49 had a low LAA emptying velocity (LAAEV). The low-velocity group was older, with a mean age of 75 years compared to 70 years in the high-velocity group. The severity of mitral regurgitation was similar between the two groups. Patients with reduced LAA emptying velocity required significantly higher joules for successful cardioversion compared to the high-velocity group (192 joules vs. 155 joules, p-value = 0.02). Sleep apnea was more prevalent in the high-velocity group. The utilization of antiarrhythmic medications did not differ significantly between the groups (55% vs. 63%, p-value = 0.25). Conclusions: The study showed AF patients with low LAA emptying velocity require higher energy levels for successful cardioversion, suggesting that LAA emptying velocity may serve as a predictor of energy requirement in DC cardioversion for restoring sinus rhythm in AF patients.

Incidence, risk factors, and outcomes of atrial functional mitral regurgitation in patients with atrial fibrillation or sinus rhythm.

Atrial functional mitral regurgitation (AFMR) has been associated with atrial fibrillation (AF) and heart failure with preserved ejection fraction. However, data on incident AFMR are scarce. We aimed to study the incidence, risk factors, and clinical significance of AFMR in AF or sinus rhythm (SR). Adults with new diagnosis of AF and adults in SR were identified. Patients with >mild MR at baseline, primary mitral disease, cardiomyopathy, left-sided valve disease, previous cardiac surgery, or with no follow-up echocardiogram were excluded. Diastolic dysfunction (DD) was indicated by ≥2/4 abnormal diastolic function parameters [mitral medial e', mitral medial E/e', tricuspid regurgitation velocity, left atrial volume index (LAVI)]. Overall, 1747 patients with AF and 29 623 in SR were included. Incidence rate of >mild AFMR was 2.6 per 100 person-year in new-onset AF and 0.7 per 100 person-year in SR, P < 0.001. AF remained associated with AFMR in a propensity score-matched analysis based on age, sex, and comorbidities between AF and SR [hazard ratio: 3.80 (95% confidence interval 3.04-4.76)]. Independent risk factors associated with incident AFMR were age ≥65 years, female sex, LAVI, and DD in both AF and SR, in addition to rate (vs. rhythm) control in AF. Incident AFMR was independently associated with all-cause death in both groups (both P < 0.001). AF conferred a three-fold increase in the risk of incident AFMR. DD, older age, left atrial size, and female sex were independent risk factors in both SR and AF, while rhythm control was protective. AFMR was universally associated with worse mortality.

Individuals with chronic epilepsy have elevated P-wave heterogeneity comparable to patients with atrial fibrillation.

Identification of epilepsy patients with elevated risk for atrial fibrillation (AF) is critical given the heightened morbidity and premature mortality associated with this arrhythmia. Epilepsy is a worldwide health problem affecting nearly 3.4 million people in the United States alone. The potential for increased risk for AF in patients with epilepsy is not well appreciated, despite recent evidence from a national survey of 1.4 million hospitalizations indicating that AF is the most common arrhythmia in people with epilepsy. We analyzed inter-lead heterogeneity of P-wave morphology, a marker reflecting arrhythmogenic nonuniformities of activation/conduction in atrial tissue. The study groups consisted of 96 patients with epilepsy and 44 consecutive patients with AF in sinus rhythm before clinically indicated ablation. Individuals without cardiovascular or neurological conditions (n = 77) were also assessed. We calculated P-wave heterogeneity (PWH) by second central moment analysis of simultaneous beats from leads II, III, and aVR ("atrial dedicated leads") from standard 12-lead electrocardiography (ECG) recordings from admission day to the epilepsy monitoring unit (EMU). Female patients composed 62.5%, 59.6%, and 57.1% of the epilepsy, AF, and control subjects, respectively. The AF cohort was older (66 ± 1.1 years) than the epilepsy group (44 ± 1.8 years, p < .001). The level of PWH was greater in the epilepsy group than in the control group (67 ± 2.6 vs. 57 ± 2.5 μV, p = .046) and reached levels observed in AF patients (67 ± 2.6 vs. 68 ± 4.9 μV, p = .99). In multiple linear regression analysis, PWH levels in individuals with epilepsy were mainly correlated with the PR interval and could be related to sympathetic tone. Epilepsy remained associated with PWH after adjustments for cardiac risk factors, age, and sex. Patients with chronic epilepsy have increased PWH comparable to levels observed in patients with AF, while being ~20 years younger, suggesting an acceleration in structural change and/or cardiac electrical instability. These observations are consistent with emerging evidence of an "epileptic heart" condition.

Incidence of stroke in patients with hypertrophic cardiomyopathy in stable sinus rhythm during long-term monitoring

IntroductionPatients with hypertrophic cardiomyopathy (HCM) are at increased risk of stroke, but the incidence and factors associated with cardioembolic events in HCM patients without atrial fibrillation (AF) remain unresolved. We determined the incidence of stroke in patients in sinus rhythm (SR) monitored with a cardiac implantable electronic device (CIED). MethodsAll consecutive patients diagnosed with HCM and referred to CIED implantation with >16 years at diagnosis and ≥ 1 year follow-up post CIED implantation were retrospectively reviewed. Severe LA dilatation was defined as ≥48 mm. Patients were stratified by rhythm as: Pre-existing AF (AF present prior to CIED); De novo AF (AF present after CIED implantation); SR: no episodes of AF. ResultsOf 1651 patients, 185 (11.2%) implanted with a CIED were included (57% men, age: 54 ± 17 years). Baseline, pre-existing AF was present in 73 (39%) patients. Ischemic stroke was reported in 19 (10.3%, 1.78%/year) patients and was similar across the three groups (2.3%/year vs 1.1%/year vs 0.6%/year in patients in SR vs pre-existing AF vs de novo AF, respectively, p = 0.235).In SR patients, a LAD≥48 mm posed the greatest risk of stroke (Hazard Ratio: 10.03,95% Confidence-Interval 2.79–16.01). At Cox multivariable analysis, after adjustment for oral anticoagulation, LA was independently associated with stroke while rhythm was not. Conclusionsin HCM patients with CIED long-term monitoring and no prior history of AF, stroke rates were similar in those with de novo AF or stable SR. Severe LA dilatation was a powerful risk factor, irrespective of AF.

Atrial contractile function and fibrosis in patients with paroxysmal atrial fibrillation in sinus rhythm

Atrial contractile function and fibrosis in patients with paroxysmal atrial fibrillation in sinus rhythm

Сardioprotective agents with biaromatic structure. Part 4. Potassium hERG channels blockers and modulators

The hERG subtype potassium channel (Kv11.1) is one of the most important and one of the most studied biological targets for the creation of cardioprotective agents. A large number of both blockers and activators/modulators of the hERG channel have been described with biaromatic structure. Substances with an hERG-mechanism are used primarily for the effective regulation of the action potential duration in the heart tissues and for the control of the QT interval on the electrocardiogram. Among the hERG blockers, the most well-known drug is dofetilide, which is used to maintain sinus rhythm in atrial fibrillation. The review presents all currently known ligands of the hERG channel with a biaromatic structure and the data on their biological properties.

Atrial contractile function and fibrosis in patients with paroxysmal atrial fibrillation in sinus rhythm

The aim of the study was to investigate atrial contractile function in patients with paroxysmal atrial fibrillation (AF) in sinus rhythm using transthoracic echocardiography (EchoCG). Thirty-five patients with paroxysmal AF and arterial hypertension (mean age 62 ± 10 years, 43% male) in sinus rhythm were enrolled in the study. The control group was composed of comparable patients with arterial hypertension without heart rhythm disturbances. EchoCG was performed during sinus rhythm according to an extended protocol, which included the ejection fraction (EF) of the left atrium (LA) and tissue Doppler measurements. Myocardial fibrosis was assessed quantitatively by videodensitometry in intraventricular and intraatrial (IAS) septa using an original image post-processing algorithm. We found a significant decrease in the left atrial contraction function during sinus rhythm in patients with AF when compared to controls. LA EF (34 ± 14 vs. 54 ± 17, p = 0.03) and A' velocity (0.17 ± 0.04 vs. 0.22 ± 0.04, p = 0.008) decreased while A/A' ratio (2.7 ± 0.2 vs. 1.9 ± 0.1, p = 0.006) increased. Peak A velocity was not affected. Videodensitometric analysis revealed a 2.3-fold increase in IAS fibrosis fraction in AF patients compared with controls (p = 0.01). Patients with AF in sinus rhythm have markedly depressed atrial contractile function. Videodensitometry of IAS has the potential to be used as inexpensive method of atrial fibrosis assessment in patients with AF.

Does conduction heterogeneity determine the supervulnerable period after atrial fibrillation?

Atrial fibrillation (AF) resumes within 90 s in 27% of patients after sinus rhythm (SR) restoration. The aim of this study is to compare conduction heterogeneity during the supervulnerable period immediately after electrical cardioversion (ECV) with long-term SR in patients with AF. Epicardial mapping of both atria was performed during SR and premature atrial extrasystoles in patients in the ECV (N = 17, age: 73 ± 7 years) and control group (N = 17, age: 71 ± 6 years). Inter-electrode conduction times were used to identify areas of conduction delay (CD) (conduction times 7–11 ms) and conduction block (CB) (conduction times ≥ 12 ms). For all atrial regions, prevalences and length of longest CB and continuous CDCB lines, magnitude of conduction disorders, conduction velocity, biatrial activation time, and voltages did not differ between the ECV and control group during both SR and premature atrial extrasystoles (p ≥ 0.05). Hence, our data suggest that there may be no difference in biatrial conduction characteristics between the supervulnerable period after ECV and long-term SR in AF patients.Graphical abstractThe supervulnerable period after AF termination is not determined by conduction heterogeneity during SR and PACs. It is unknown to what extent intra-atrial conduction is impaired during the supervulnerable period immediately after ECV and whether different right and left atrial regions are equally affected. This high-resolution epicardial mapping study (upper left panel) of both atria shows that during SR the prevalences and length of longest CB and cCDCB lines (upper middle panel), magnitude of conduction disorders, CV and TAT (lower left panel), and voltages did not differ between the ECV and control group. Likewise, these parameters were comparable during PACs between the ECV and control group (lower left panel). †Non-normally distributed. cm/s = centimeters per second; mm = millimeter; ms = millisecond; AF = atrial fibrillation; AT = activation time; BB = Bachmann’s bundle; cCDCB = continuous lines of conduction delay and block; CB = conduction block; CD = conduction delay; CT = conduction time; CV = conduction velocity; ECV = electrical cardioversion; LA = left atrium; LAT = local activation times; PAC = premature atrial complexes; PVA = pulmonary vein area; RA = right atrium; SR = sinus rhythm; TAT = total activation time.

Amiodarone therapy and risk of primary lung cancer; insights from a real-life contemporary population study

Abstract Background Amiodarone is the most effective antiarrhythmic therapy to maintain sinus rhythm in atrial fibrillation (AF) patients. There is a controversy regarding the association of amiodarone therapy with an increased risk of lung cancer. We aimed to assess the relationship between amiodarone treatment and primary lung cancer (PLC) incidence in a contemporary population of AF patients. Methods This is a retrospective study among patients from the Southern district of Clalit Health Services in Israel between 1st January 1999 and 1st July 2021. The study population comprised solely of patients with atrial fibrillation since this is the most prevalent condition for prescribing amiodarone. Patients treated with amiodarone were matched in a 1:1 manner with controls not exposed to amiodarone based on age, sex, living area, and atrial fibrillation diagnosis duration. To avoid immortal time bias, follow-up times of the matched controls were left adjudicated to truncate the amiodarone-free period of their matched cases. Patients with prior PLC were excluded. The primary outcome was the incidence of any PLC. We performed survival analyses using multivariable Cox regression controlling for potential confounders. Results During the study period, 7,048 patients who initiated amiodarone treatment were identified, of whom 6,449 were matched with controls. The mean age was 71.5 years, and 46.4% were women among the matched population. The amiodarone-treatment group had higher rates of smoking (30.3% vs. 26.8%), prior non-lung-related malignancy (14.9% vs. 13.5%), rheumatic disease (4.5% vs. 3.5%), diabetes (38.3% vs. 32.6%), history of myocardial infarction (316% vs. 19.6%), renal failure (17.2% vs. 10.8%) and congestive heart failure (33.8% vs. 20.7%); p&amp;lt;0.05 for all. During the study, with a mean follow-up time of 5.7 years, PLC occurred in 94 (1.5%) patients in the amiodarone group and 79 (1.2%) patients in the control group [adjusted-hazard-ratio (aHR) 1.10 (confidence-interval 95% (CI95%, 0.78,1.55), p=0.6]. Factors independently associated with increased PLC risk were smoking [aHR 4.25 CI95% (3.01,5.99), p&amp;lt;0.001], non-lung-related malignancy [aHR 1.56, CI95% (1.00,2.42), p=0.050], and peripheral vascular disease [aHR 1.77, CI95% (1.16,2.71), p=0.008] Conclusion Chronic amiodarone treatment is not associated with increased risk for PLC. Smoking and prior non-lung-related malignancy and peripheral vascular disease were independently associated with increased PLC risk, suggesting that such patients should undergo closer surveillance for early detection of PLC. Funding Acknowledgement Type of funding sources: None.

The state of systolic and diastolic functions of the left ventricle and heart rate variability in patients with atrial fibrillation after infection of COVID-19

Abstract Introduction It is known that atrial fibrillation (AF) is one of the most common arrhythmias in patients (pts) who have had a COVID-19 infection (CI). The aim of our study was to evaluate systolic and diastolic functions of the left ventricle (LV) and heart rate variability (HRV) in pts with AF depending on the past CI. Research material and methods 131 pts with paroxysmal or persistent forms of AF in sinus rhythm were studied. 93 people had a history of an average of 6.2±0.5 months ago of COVID-19 infection. They made up the 1st group of examined pts. The remaining 38 patients did not have a history of this infection. They constituted the 2nd group of the study group, which was the control group. Transthoracic echocardiography and Holter monitoring ECG were performed according to the standard technique. Results of the study We did not find any difference in hemodynamic parameters characterizing the systolic function of LV. So, the values of the end-diastolic volume (117.0±7.6 mm and 116.0±7.2 mm), end-systolic volume (55.7±4.9 mm and 55.2±4.7 mm) and ejection fractions (55.0±2.1% and 54.4±2.0%) in the groups did not differ significantly. However, statistical significance was obtained in indicators characterizing LV diastolic function. So, significantly different flow rates in the 1st and 2nd groups of pts – E (60.8±1.63 sm/s and 94.6±2.97 sm/s, p&amp;lt;0.001), A (61.8±0.83 sm/s and 73.1±1.03 sm/s, p&amp;lt;0.001), their E/A ratios (0.98±0.02 and 1.39 + 0.03, p&amp;lt;0.001) and DE score (175.9±2.20 ms and 202.5±4.03 ms, p&amp;lt;0.001). A more significant violation of LV diastolic function after CI led to an increase in the diameter of the left atrium (LA) (4.99±0.14 cm in the 1st group compared with 4.40±0.004 sm in the 2nd group, p&amp;lt;0.001) and LA index (46.4±0.011 sm in the 1st group compared with 42.93±0.08 in the 2nd group, p&amp;lt;0.001). We also found a significant difference in such indicators of HRV between groups “1” and “2” as – SDANN (102.7±2.33 and 151.7±1.23 ms, p&amp;lt;0.001), SDNN (124, 3±4.06 and 181.3±4.83 ms, p&amp;lt;0.001), and RMSSD (100.4±4.57 and 173.2±13.51 ms, p&amp;lt;0.001). Conclusion In pts with AF, after undergoing CI, the LV diastolic function begins to suffer first, which leads to an increase in the size of the LA. Pts after CI also had a change in the autonomic regulation of the heart rhythm, and as a result, an increase in the electrical instability of the atria. Funding Acknowledgement Type of funding sources: None.

Improvement of a convolutional neural network using synthetic ECGs for the diagnosis of different atrial rhythms

Abstract Funding Acknowledgements Type of funding sources: None. Introduction The diagnostic capacity of convolutional neural networks has demonstrated its potential for the diagnosis of different ECG alterations. An important limitation of these networks is that there are classes that are underrepresented in the population, such as the Brugada pattern compared to right bundle branch block or Atrial Flutter (AFL) compared to atrial fibrillation (AF). This asymmetry that exists in any population ECG database is one of the limitations (F1-Score) that could be improved, either with even larger databases (impractical) or by creating synthetic representations of the ECG. Purpose Using a tool that allows the drawing of specific electrocardiographic patterns first and subsequently, the random creation of different ECGs based on said pattern, the diagnostic capacity of any unbalanced convolutional network could be improved. Methods Initially, a database with 95,000 ECGs from our health area was used. From this data set, 5,810 ECGs were taken that were labeled in three classes (1) Sinus Rhythm (SR), 2) AF and 3) AFL by two arrythmologists, 4,637 for training and 1,173 for validation. It was observed that the network was unbalanced (SR: 81.3% of the total, FA: 16.4% of the total and AFL: 2.2% of the total). After having demonstrated the good capacity of the network for the diagnosis of these three atrial rhythms, it was observed that the diagnostic dispersion matrix erred precisely between the ECGs of AF and AFL (figure 1). Based on this idea, it was decided to create a random pattern-based ECG creation tool. Different atrial flutter patterns were created and 2000 ECGs were synthetically created with variations of the ECG frequency, voltages and morphology. A new neural network was subsequently trained with the addition of these ECGs to the original database and its diagnostic capacity was evaluated on the same initial validation set. Results The new network showed a 88,3% sensitivity (vs 82,6%), a 100% specificity (vs 98,5%) and an 92% (vs 87,8%) accuracy. It specially had an improvement in AFL ECGs (70,2% vs 61%) and minor improvements in AF ECGs (90,8% vs 89,4%) and SRs ECGs (100% vs 98,6%) accuracy. Conclusions The creation of synthetic ECGs to improve the diagnostic capacity of neural networks for infrequent events is feasible. This application allows the development of networks applicable in real life, in this case, for the diagnosis of atrial arrhythmias.

Mitral Regurgitation and Body Mass Index Increase the Predictability of Perioperative Bleeding in Anticoagulated Patients With Nonvalvular Atrial Fibrillation.

BackgroundCatheter ablation (CA) effectively restores sinus rhythm in atrial fibrillation (AF) but causes a short-term fluctuation in the coagulation state. Potential risk factors and better management during this perioperative period remain understudied.MethodsWe consecutively included 940 patients with nonvalvular AF who received CA at Fuwai Hospital, Beijing, China. Patients were divided into two groups according to their bleeding status during 3 months' anticoagulation. Any adverse events related to bleeding in the 3 months were evaluated. The HAS-BLED score and ABC-bleeding score, as well as other potential factors, were explored to predict bleeding risk.ResultsIn this observational study, 8.0% and 0.9% of the whole population suffered from bleeding and thromboembolic events, respectively. After adjusting for known factors related to bleeding, mitral regurgitation (MR, p for trend <0.001) and body mass index (BMI, odds ratio (OR) = 0.920, 95% CI 0.852–0.993, p = 0.033) were the most significant ones. C-indexes of the HAS-BLED score and ABC-bleeding score for bleeding were 0.558 (0.492–0.624) and 0.585 (0.515–0.655), respectively. The incorporation of MR and BMI significantly improved the predictive value based on HAS-BLED score (C-index = 0.650, 95% CI 0.585–0.715, p = 0.004) and ABC-bleeding score (C-index = 0.671, 95% CI 0.611–0.731, p < 0.001). The relative risk of mild-moderate MR was 4.500 (95% CI 1.625–12.460) in patients with AF having HAS-BLED = 1 and 4.654 (95% CI 1.496–14.475) in HAS-BLED ≥ 2, while it was not observed in patients with HAS-BLED = 0 (p = 0.722).ConclusionMore severe MR and lower BMI are associated with a higher incidence of perioperative bleeding, which helps improve the predictability of increased individual bleeding risk of a patient with nonvalvular AF who has received CA therapy and oral anticoagulants.

Atrial fibrillation in old age: current treatment options

In older age, patients with atrial fibrillation (AF) have a high risk of stroke, bleeding, and death, but such patients have been underrepresented in randomized clinical trials. A search and analysis of 4 176 literature sources from the MEDLINE/ PubMed and eLIBRARY databases was carried out for the keywords «atrial fibrillation», «old age», «older», «elderly». The review includes the most important studies reflecting the current understanding of risk factors for development, complications and treatment of AF in old age. The results of therapy to control the ventricular rate, to control sinus rhythm in AF with drugs and catheter ablation are discussed. The data of studies on the prevention of thromboembolic complications in patients with AF by the use of anticoagulants and implantable devices are considered.

Cardiac Sympathetic Activity and Rhythm Control Following Pulmonary Vein Isolation in Patients with Paroxysmal Atrial Fibrillation-A Prospective 123I-mIBG-SPECT/CT Imaging Study.

Background: Pulmonary vein isolation (PVI) and antiarrhythmic drug therapy are established treatment strategies to preserve sinus rhythm in atrial fibrillation (AF). However, the efficacy of both interventional and pharmaceutical therapy is still limited. Solid evidence suggests an important role of the cardiac sympathetic nervous system in AF. In this blinded, prospective observational study, we studied left ventricular cardiac sympathetic activity in patients treated with PVI and with antiarrhythmic drugs. Prospectively, Iodine-123-benzyl-guanidine single photon emission computer tomography (123I-mIBG-SPECT) was performed in a total of 23 patients with paroxysmal AF, who underwent PVI (n = 20) or received antiarrhythmic drug therapy only (n = 3), respectively. 123I-mIBG planar and SPECT/CT scans were performed before and 4 to 8 weeks after PVI (or initiation of drug therapy, respectively). For semiquantitative SPECT image analysis, attenuation-corrected early/late images were analyzed. Quantitative SPECT analysis was performed using the AHA 17-segment model of the left ventricle. Results: PVI with point-by-point radiofrequency ablation led to a significantly (p < 0.05) higher visual sympathetic innervation defect score when comparing pre-and post PVI. Newly emerging innervation deficits post PVI were localized predominantly in the inferior lateral wall. These findings were corroborated by semiquantitative SPECT analysis identifying inferolateral segments with a reduced tracer uptake in comparison to SPECT before PVI. Following PVI, patients with an AF relapse showed a different sympathetic innervation pattern compared to patients with sufficient rhythm control. Conclusions: PVI results in novel defects of cardiac sympathetic innervation. Differences in cardiac sympathetic innervation remodelling following PVI suggest an important role of the cardiac autonomous nervous system in the maintenance of sinus rhythm following PVI.

Cardiac resynchronization therapy defibrillators in patients with permanent atrial fibrillation.

AimsThere are conflicting data on the benefit of cardiac resynchronization therapy (CRT) in heart failure (HF) patients with permanent atrial fibrillation (AF). We aimed to compare patient outcomes according to the presence or absence of permanent AF at device implantation.Methods and resultsWe retrospectively analysed remote monitoring data from 1141 CRT defibrillators. Propensity score with inverse‐probability weighting method was used to balance AF and sinus rhythm (SR) groups. Analysis endpoints included total mortality, appropriate defibrillation shocks, and CRT percentage. There were 229 patients (20.1%) in the AF group and 912 patients (79.9%) in the SR group. Compared with SR patients, AF patients were older (median age, 77 vs. 72 years, P < 0.001), more frequently male (82.5% vs. 75.5%, P = 0.02), and had higher heart rate (75.7 vs. 71.0 b.p.m., P < 0.001). Of the 229 AF patients, 162 (70.7%) received suboptimal CRT (<98%) and 67 (29.3%) had adequate CRT (≥98%). During a median follow‐up of 24 months, total mortality did not differ between AF and SR groups (propensity‐score‐weighted hazard ratio, HR 1.32 [95% confidence interval, 0.82–2.15], P = 0.25). The risk of appropriate shocks was significantly higher in the AF group with <98% CRT than in the SR group (weighted‐HR, 1.99 [1.21–3.26], P = 0.006) and was similar in the AF group with ≥98% CRT versus the SR group (1.29 [0.66–2.53], P = 0.45). During follow‐up, sinus rhythm was recovered in 23 patients in the AF group (10%) after a median time of 106 (42–256) days. The rate of sinus rhythm recovery in the AF group was 4.5 (95% CI, 2.8–6.7) per 100 patient‐years; the rate of permanent AF occurrence in the SR group was 2.5 (95% CI, 1.9–3.3) per 100 patient‐years.ConclusionsAlthough mortality was similar across patient groups, patients with permanent AF and suboptimal CRT had twofold higher risk of appropriate shocks than SR patients or AF patients with CRT ≥ 98%.

Is circulating Gla-rich protein linked with coronary calcium and cardiovascular pathology in patients with atrial fibrillation or heart failure? A pilot study

Introduction: Nowadays Gla-rich protein (GRP) is recognized as a novel biomarker playing a pivotal role in the crosstalk between chronic inflammation and vascular calcification. Aim: The aim of this article is to study the link between circulating GRP, cardiovascular pathology, and the degree of arterial calcification evaluated by the coronary arterial calcium score (CACS) in a Bulgarian population sample. Materials and Methods: Adult participants (n = 81) of both genders were divided into: controls (n = 41)—subjects with estimated moderate-to-high risk without known cardiovascular diseases (CVDs) and a combined CVD group (n = 40)—patients with paroxysmal or persistent atrial fibrillation in sinus rhythm, and heart failure subjects with preserved ejection fraction. A structured interview was carried out for evaluation of the classical CVD risk factors. CACS was determined by multislice computed tomography. Routine laboratory parameters were extracted from medical records. Serum levels of total GRP, matrix Gla protein, and osteocalcin were estimated by commercial ELISA kits. Standard statistical methods (descriptive statistics, Student’s t-test and Spearman’s correlation) were applied. Statistical significance was considered at p&lt;0.05. Results: Significantly lower GRP levels were established in patients with coronary calcium compared to those without calcium deposits. Clear tendency for decreased levels of GRP was observed in the combined CVD group vs controls. Circulating GRP significantly correlates with uncarboxylated matrix Gla protein. An association between serum GRP, CRP, and low-density lipoproteins (LDLs) was demonstrated. Conclusion: This study adds new information regarding the role of circulating GRP as a new player in calcification inhibition. Our findings illuminate the link between total circulating GRP, CVD pathology, and the degree of coronary calcification.