ARTICLE | doi:10.20944/preprints202103.0382.v1
Subject: Medicine & Pharmacology, Allergology Keywords: diastolic dysfunction; heart failure; atrial fibrillation; atrial hypertension; left atrial pressure
Online: 15 March 2021 (13:02:14 CET)
Introduction: Left atrial hypertension is one of the pathophysiologies of heart failure with preserved ejection fraction. We hypothesized that left atrial pressure response (LAPR) to incremental pacing is higher in patients with atrial fibrillation (AF) and can predict left ventricular diastolic dysfunction. Methods: Patients requiring left atrial access as a part of a therapeutic procedure for AF (n=204, AF group) or supraventricular tachycardia (n=34, control group) were analyzed (male n=183, 54±12 years old). LAPR was measured during incremental pacing. Results: Baseline left atrial pressure and LAPR at all pacing rates were not different between the AF and control groups. They were higher in patients with a high E/e’ (≥ 8) than in those with a low E/e’ (< 8). LAPR at a pacing interval of 400ms and E/e' were positively correlated (r=0.373, p<0.001). Body mass index and a high E/e' were independent predictors of pacing-induced left atrial hypertension. Conclusions: The LAPR to incremental pacing was constant regardless of AF. The non-invasive echocardiographic marker E/e' reflected pacing-induced left atrial hypertension.
REVIEW | doi:10.20944/preprints202007.0117.v1
Subject: Medicine & Pharmacology, Cardiology Keywords: electrocardiography; P-wave; interatrial conduction block; atrial fibrillation
Online: 7 July 2020 (08:43:01 CEST)
Prediction and early detection of atrial fibrillation (AF) remain a permanent challenge in everyday practice. Timely identification of an increased risk for AF episodes (which are frequently asymptomatic) is essential in the primary and secondary prevention of cardioembolic events. One of the noninvasive modalities of AF prediction is represented by the electrocardiographic P-wave analysis. This includes the study and diagnosis of interatrial conduction block (Bachmann`s bundle block). Bayés’ Syndrome (named after its first descriptor) denotes the association between interatrial conduction defect and supraventricular arrhythmias (mainly AF) predisposing to cardioembolic events. Our short review presents an update of the most important data concerning this syndrome: brief history, main ECG features, pathophysiological background and clinical implications.
ARTICLE | doi:10.20944/preprints201804.0037.v1
Subject: Medicine & Pharmacology, Clinical Neurology Keywords: brain vessel; ischemic stroke; non-valvular atrial fibrillation
Online: 3 April 2018 (11:07:39 CEST)
Objective: It was aimed to investigate the cerebral vascular territories in stroke patients with NVAF as an etiologic factor. Material and Methods: A total of 104 patients who were referred to our hospital between January 2015 and September 2016, who were over 55 years of age, identified or documented as having a standard ECG or Holter ECG record on their medical history, and diagnosed with stroke were included. Our study was designed as a retrospective analysis of prospective data. Detailed history, physical examination and electrocardiography (ECG) evaluations of the patients were performed. Descriptive statistics were used in the detection of findings, and t-test, Pearson-square test and Fisher's exact test were used for differences analysis. Results: 53.8% (N = 56) of the patients were male and 46.2% (N = 48) were female. The mean age was 73.5. MCA was the most common site of vascular involvement in NVAF-dependent strokes. In MCA vascular territory, ischemic infarcts were detected most frequently in the upper and lower divisions. SCA and PCA followed MCA. Approximately 64% of the NVAF-related strokes were anterior circulation infarction (ASE) and 22% were posterior circulation infarct (PSE). There was a significant difference in age and past stroke history factors in favor of ASE (p<0.05). There was no significant difference between ASE and PSE in HT, cardiac history and DM factors (p>0.05). Conclusion: It was emphasized that the area of the vessel that underwent ischemia in the acutely displayed infarcts and the etiological factor for this vessel area could be predicted
ARTICLE | doi:10.20944/preprints201704.0156.v1
Subject: Medicine & Pharmacology, Allergology Keywords: ranolazine; atrial fibrillation; prevention; pharmacological cardioversion; meta-analysis
Online: 25 April 2017 (07:48:26 CEST)
Introduction Recent evidence from relatively small randomized controlled trials would seem to support a useful role of ranolazine for the prevention and treatment of atrial fibrillation (AF). The present study is aimed at providing information about the possible beneficial anti-arrhythmic properties of ranolazine. In particular, the meta-analysis carried out in this study focuses on the application of ranolazine to prophylaxis and treatment of atrial fibrillation.Methods Both randomized controlled trials (RCTs) and non randomized observational studies concerning the effects of ranolazine on AF were included in the meta-analysis. In each of the considered studies, a comparison was made between a group of patients taking ranolazine and a second group treated instead with another antiarrhythmic therapy , or assigned to placebo. Efficacy outcomes were the risk of new- onset AF, the probability of conversion to sinus rhythm of patients with recent occurrence(≤ 48 h)of AF and the time to conversion to sinus rhythm. Safety endpoints were death, adverse events, QTc prolongation and hypotension.Results Ten studies ( 8 RCTs and 2 nonrandomized observational studies) were gathered on the whole. Ranolazine was effective in preventing the occurrence of AF when compared to controls (RR= 0.60; 95% CI: 0.43–0.83; p = 0.002). Subgroup analysis showed a more pronounced preventive effect of ranolazine against AF in the postoperative setting of coronary artery bypass grafting(CABG) surgery (RR= 0.39; 95% CI: 0.18-0.83; p=0.02) when compared to non- postoperative AF (RR= 0.76; 95% CI: 0.63-0.92; p=0.04). Ranolazine enhanced the chances of successful cardioversion when added to intravenous amiodarone compared to amiodarone alone (RR 1.18; 95% CI: 1.05–1.33; p = 0.004) and significantly decreased the time to cardioversion(SMD= −10.35 h; 95% CI: −18.13 hours to − 2.57 hours; p < 0.001). Overall risks of death, adverse events, and QTc prolongation were shown to be similar in the comparison between patients treated with ranolazine and controls. Conclusions Ranolazine given orally at appropriate doses showed the property to significantly quicken the conversion of AF to sinus rhythm when combined with the iv amiodarone, compared to iv amiodarone alone . Furthermore, in patients in sinus rhythm, ranolazine proved to reduce the frequency of new onset AF as well as of its recurrences, especially in patients undergone CABG surgery, known to be at high risk of developing postoperative AF. In addition, ranolazine use seems to be safe and associated with relatively few adverse events.
ARTICLE | doi:10.20944/preprints202202.0103.v1
Subject: Life Sciences, Molecular Biology Keywords: heart disease; atrial fibrillation; atrial fibrosis; transcriptome; microRNA; RNA sequencing; syndecan-1; miR-302
Online: 7 February 2022 (19:01:55 CET)
Atrial fibrillation (AF) is a form of sustained cardiac arrhythmia and microRNAs (miRs) play crucial roles in pathophysiology of AF. To identify novel miR-mRNA pairs, we performed RNAseq from atrial biopsies of AF and non-AF patients. Differentially expressed miRs (11-down and 9-up) and mRNAs (95-up and 82-down) were identified and hierarchically clustered in a heat-map. Subsequently, GO, KEGG, and GSEA analyses were run to identify deregulated pathways. Then, miR targets were predicted in miRDB database, and a regulatory network of negatively correlated miR-mRNA pairs was constructed using Cytoscape. To select potential candidate genes from GSEA analysis, top-50 enriched genes in GSEA were overlaid with predicted targets of differentially deregulated miRs. Besides, protein-protein-interaction (PPI) network of enriched genes in GSEA was constructed, and subsequently GO and canonical pathway analyses were run for genes in PPI network. Our analyses showed that TNF-α, p53, EMT, and SYDECAN1 signaling were among the highly affected pathways in AF samples. SDC-1 (syndecan-1) was the top-enriched gene in p53, EMT, and SYDECAN1 signaling. Consistently, SDC-1 mRNA and protein levels were significantly higher in atrial samples of AF patients. Among negatively correlated miRs, miR-302b-3p was experimentally validated to suppress SDC-1 transcript levels. Overall, our results suggested that miR-302b-3p/SDC-1 axis may involve in pathogenesis of AF.
CASE REPORT | doi:10.20944/preprints202205.0329.v1
Subject: Medicine & Pharmacology, Cardiology Keywords: Apple Watch; wearable sensor; pulse rate; arrhythmia; atrial fibrillation; case report
Online: 24 May 2022 (09:49:08 CEST)
Consumer rhythm-monitoring devices, such as the Apple Watch, are becoming more readily available. Irregular pulses can be detected using an optical sensor built into the wearable device. The Apple Watch (Apple Inc., Cupertino, CA, USA) is a class II medical device with pulse rate and electrocardiography (ECG) monitoring capabilities. Here we report a case in which an arrhythmia that was conventionally perceived but undiagnosed was identified as atrial fibrillation by self-acquisition of ECG data using an Apple Watch.
ARTICLE | doi:10.20944/preprints202108.0398.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: Direct oral anticoagulants (DOACs); Nonvalvular atrial fibrillation (NVAF); Real-world experience
Online: 19 August 2021 (10:32:56 CEST)
The aim is to evaluate a program for direct oral anticoagulants (DOACs) management in nonvalvular atrial fibrillation (NVAF) patients, according to patient profiles, appropriateness of dosing, patterns of crossover, effectiveness and safety. This is an observational and longitudinal retrospective study in a cohort of patients attended in daily clinical practice in a single regional hospital in Spain with a systematic follow-up plan for up to 3 years for patients initiating dabigatran, rivaroxaban or apixaban between JAN/2012-DEC/2016. We analyzed 490 episodes of treatment (apixaban 2.5 mg: 9.4%, apixaban 5 mg: 21.4%, dabigatran 75 mg: 0.6%, dabigatran 110 mg: 12,4%, dabigatran 150 mg: 19.8%, rivaroxaban 15 mg: 17.8% and rivaroxaban 20 mg: 18.6%) in 445 patients. 13.6% of patients on dabigatran, 9.7% on rivaroxaban, and 3.9% on apixaban, switched to other DOACs or changed dosing. Apixaban was the most frequent DOAC switched to. The most frequent reasons for switching were toxicity (23.8%), bleeding (21.4%) and renal deterioration (16.7%). Inappropriateness of dose was found in 23.8% of episodes. Patients taking apixaban 2.5 mg were older, had higher CHA2DS2VASc score and lower creatinine clearance. Patients taking dabigatran 150 mg and rivaroxaban 20 mg were younger, had lower CHA2DS2VASc and higher creatinine clearance. Rates of stroke/transient ischemic attack (TIA) were 1.64/0.54 events/100 patients-years, while rates of major, clinically relevant non-major (CRNM) bleeding and intracranial bleeding where 2.4, 5, and 0.5 events/100 patients-years. Gastrointestinal and genitourinary bleeding were the most common type of bleeding events (BE). On multivariable analysis, prior stroke (RR: 4.2; CI: 1.5-11.8; p=0.006) and age (RR: 1.2; CI: 1.1-1.4; p=0.006) were independent predictors of stroke/TIA. Concurrent platelet inhibitors (RR: 7.1; CI: 2.3-21.8; p=0.001), male gender (RR: 2.1; CI: 1.2-3.7; p=0.0012) and age (RR: 1.1; CI: 1.02-1.13; p=0.005) were independent predictors of BE. This study complements the scant data available on the use of DOACs in NVAF patients in Spain, confirming a good safety and effectiveness profile
ARTICLE | doi:10.20944/preprints202107.0354.v1
Subject: Medicine & Pharmacology, Cardiology Keywords: heart failure; mid-range ejection fraction; atrial fibrillation; cardiac inflammation; cardiac fibrosis; risk factors.
Online: 15 July 2021 (10:18:01 CEST)
Aims: Heart failure (HF) is frequently accompanied by atrial fibrillation (AF), a combination that worsens the outcomes of both diseases. Despite advances in the treatment of AF, it remains a serious and unsolved problem for clinicians and researchers. The aim of this study was to examine risk factors for incidents of paroxysmal and persistent AF in patients having heart failure with mid-range ejection fraction (HFmrEF). Methods. Overall, 71 patients with HFmrEF and non-valvular AF, including paroxysmal and persistent types, were enrolled in this study. As a control group, 42 HFmrEF patients without AF were also enrolled. All patients underwent detailed physical examination, including resting electrocardiography, echocardiography, and 24-hour ambulatory Holter monitoring. Levels of the inflammation markers high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), and tumor necrosis factor α (TNF-α) and the fibrotic marker transforming growth factor-β1 (TGF-β1) were measured by ELISA and expressed as odds ratios. Results: We show that paroxysmal AF was associated with higher diastolic blood pressure, whereas both paroxysmal and persistent forms of AF were associated with more frequent occurrence of hypertensive crisis episodes and greater body mass index. Progression from paroxysmal to persistent AF was associated with significant ventricular remodeling. Persistent and paroxysmal AF were associated with higher levels of inflammatory markers when compared to HFmrEF patients having no AF. In addition, TGF-1 was significantly increased in HFmrEF patients having persistent but not paroxysmal AF. Conclusions: Occurrence of AF, first paroxysmal and then persistent, in HFmrEF patients is associated with left ventricular remodeling and the appearance of systemic inflammatory and fibrotic markers. Changes in those parameters may be indicators by which to identify patients at increased risk of atrial fibrillation. Further studies are needed to determine the prognostic validity of these markers.
REVIEW | doi:10.20944/preprints202107.0702.v1
Subject: Medicine & Pharmacology, Cardiology Keywords: telemonitoring; telemedicine; telecardiology; cardiology; wearable; sensors; consumer health devices; cardiovascular disease; heart failure; atrial fibrillation
Online: 30 July 2021 (13:22:06 CEST)
(1) Background: New sensor technologies in wearables and other consumer health devices open up promising opportunities to collect real-world data. As cardiovascular diseases remain reason number one for disease and mortality worldwide, cardiology offers potent monitoring use-cases with patients in their out-of-hospital daily routine. Therefore, the aim of this systematic review is to investigate the status quo of studies monitoring patients with cardiovascular risks and patients suffering from cardiovascular diseases in a telemedical setting using not only a smartphone-based app, but also consumer health devices such as wearables and other sensor-based devices. (2) Methods: A literature search was conducted across five databases and the results were examined according to the study protocols, technical approaches and qualitative and quantitative parameters measured. (3) Results: Out of 166 articles, 8 studies were included in this systematic review. These cover interventional and observational monitoring approaches in the area of cardiovascular diseases, heart failure and atrial fibrillation using various app, wearable and health device combination. (4) Conclusions: Depending on the researcher’s motivation a fusion of apps, patient reported outcome measures and non-invasive sensors can be orchestrated in a meaningful way adding major contributions to monitoring concepts for both, individual patients and larger cohorts.
REVIEW | doi:10.20944/preprints202106.0541.v1
Subject: Biology, Physiology Keywords: cardiac arrhythmias; atrial fibrillation; PITX2; computational model; electrical remodelling; structural remodelling; calcium handling; mRNA; electrophysiology
Online: 22 June 2021 (12:32:52 CEST)
Atrial fibrillation (AF) is a common arrhythmia. Better prevention and treatment of AF are needed to reduce AF-associated morbidity and mortality. Several major mechanisms cause AF in patients, including a genetic predisposition to develop AF. Genome-wide association studies have identified genetic variants associated with AF populations, with the strongest hits clustering on chromosome 4q25, close to the gene coding for the homeobox transcription PITX2. Because of the inherent complexity of the human heart, experimental and basic research on PITX2-dependent AF is not sufficient for understanding atrial functional proprieties. Linking PITX2 to ion channels, cells, tissues, atria and the whole heart, computational models are necessary for achieving a quantitative understanding of atrial structure and function in PITX2-dependent AF. Computational approaches are used to capture all that we know about PITX2-dependent AF and to develop improved therapies. In the present review, we discuss advances in atrial modelling and focus on the mechanistic links between PITX2 and AF. Challenges in applying models for improving patient health are described, as well as a summary of future perspectives.
ARTICLE | doi:10.20944/preprints202205.0392.v1
Subject: Life Sciences, Biophysics Keywords: atrial-fibrillation; multi-target; drug promiscuity; druggable binding site; flecainide; Nav1.5; Kv1.5; binding site comparison; polypharmacology
Online: 30 May 2022 (10:10:41 CEST)
Atrial fibrillation (AF) is the most common cardiac arrhythmia. Its treatment includes antiarrhythmic drugs (AADs) to modulate the function of cardiac ion channels. However, AADs have been limited by proarrhythmic effects, non-cardiovascular toxicities as well as often modest antiarrhythmic efficacy. Theoretical models showed that combined blockade of Nav1.5 (and its current INa) and Kv1.5 (and its current, IKur) ion channels yield a synergistic anti-arrhythmic effect without effect on ventricles. We focused on Kv1.5 and Nav1.5 to search for structural similarities in their binding site (BS) for flecainide (a common blocker and widely prescribed AAD), as a first step for prospective rational multi-target directed ligand (MTDL) design strategies. We presented a computational workflow for flecainide BS comparison in a flecainide-Kv1.5 docking model and a solved structure of flecainide-Nav1.5 complex. The workflow includes docking, molecular dynamics, BS characterization and pattern matching. We identified a common structural pattern in flecainide BS for these channels. The latter belongs to the inner cavity and consist of a hydrophobic patch and a polar region, involving residues from S6 helix and P-loop. Since the rational MTDL design for AF is still incipient, our findings could advance multi-target atrial-selective strategies for AF treatment.
ARTICLE | doi:10.20944/preprints202011.0616.v1
Subject: Medicine & Pharmacology, Allergology Keywords: action potential; atrial fibrillation; in silico model; population of models; Class I antiarrhythmic drugs; flecainide; disopyramide; quinidine; propafenone; Pitx2
Online: 24 November 2020 (13:28:26 CET)
Electrical remodelling as a result of the homeodomain transcription factor 2 (Pitx2)‐dependent gene regulation was linked to atrial fibrillation (AF) and AF patients with single nucleotide polymorphisms at chromosome 4q25 responded favorably to Class I antiarrhythmic drugs (AADs). The possible reasons behind this remain elusive. The purpose of this study was to assess the efficacy of AADs disopyramide, quinidine, and propafenone on human atrial arrhythmias mediated by Pitx2-induced remodelling, from a single cell to the tissue level, using drug binding models with multi-channel pharmacology. Experimentally calibrated populations of human atrial action potential (AP) models in both sinus rhythm (SR) and Pitx2-induced AF conditions were constructed by using two distinct models to represent morphological subtypes of AP. Multi-channel pharmacological effects of disopyramide, quinidine, and propafenone on ionic currents were considered. Simulated results showed that Pitx2-induced remodelling increased maximum upstroke velocity (dVdtmax) and conduction velocity (CV), and decreased AP duration (APD) and wavelength (WL). At the concentrations tested in this study, these AADs decreased dVdtmax and CV and prolonged APD in the setting of Pitx2-induced AF. Our findings of alterations in WL indicated that quinidine and disopyramide may be more effective against Pitx2-induced AF than propafenone by prolonging WL.
ARTICLE | doi:10.20944/preprints202103.0015.v2
Subject: Medicine & Pharmacology, Allergology Keywords: anticoagulant; atrial; thrombosis; dabigatran; monitoring
Online: 19 April 2021 (13:28:58 CEST)
Background: Patients with atrial fibrillation (AF), lasting >48 h, considered for cardioversion, are recommended ≥3 weeks of oral anticoagulation before sinus rhythm restoration because of high risk of development of left atrial thrombosis (LAT) and stroke. However, the optimal duration of anticoagulation in the presence of overt LAT is unknown. Methods: An open-label study, aiming to investigate the prevalence of spontaneous echo con-trast (SEC) and LAT before and after 3 weeks of direct oral anticoagulant (DOAC) treatment. We included 51 consecutive patients (50.9% males), mean age 69.3±7.4 years with paroxys-mal/unknown duration of AF, considered for cardioversion, who agreed to have transesophage-al echocardiography at enrollment and 3 weeks later. Results: At baseline SEC was present in 26 (50.9%) and LAT in 10 (19.6%) of 51 patients. After 3 weeks on DOAC, SEC persisted in 12 (25.0%) and LAT in 7 (14.5%) of 48 patients, p<0.05 vs base-line. Factors, associated most strongly with persistence of SEC/LAT were left atrial appendage (LAA) emptying velocity <20 cm/s (OR=2.82), LAA lobes >2 (OR=1.84) and indexed left atrial volume ≥34 ml/m2 (OR=1.37). Conclusions: The recommended minimal period of 3 weeks of oral anticoagulation lead to SEC/LAT resolution in 47% of our patients. To our opinion, LA/LAA morphology and function should be taken into account when determining the duration of DOAC treatment before planned cardioversion.
Subject: Life Sciences, Cell & Developmental Biology Keywords: emerin; atrial cardiac defects; BAF; actin; mechano-transduction
Online: 15 May 2019 (11:09:44 CEST)
Emerin is a nuclear envelope protein that contributes to genome organization and cell mechanics. Through its N-terminal LEM-domain, emerin interacts with the DNA-binding protein Barrier-to-Autointegration (BAF). Emerin also binds to members of the Linker of the Nucleoskeleton and Cytoskeleton (LINC) complex. Mutations in the gene encoding emerin are responsible for the majority of cases of X-linked Emery-Dreifuss Muscular Dystrophy (X-EDMD). Most of these mutations lead to an absence of emerin. A few missense and short deletion mutations in the disordered region of emerin are also associated with X-EDMD. More recently, missense and short deletion mutations P22L, ∆K37 and T43I were discovered in emerin LEM-domain, associated with isolated atrial cardiac defects (ACD). Here we reveal which defects, at both molecular and cellular levels, are elicited by these LEM-domain mutations. Whereas DK37 mutation impairs correct folding of the LEM-domain, P22L and T43I have no impact on the 3D structure of emerin. Surprisingly, all three mutants bind to BAF, albeit with a weaker affinity in the case of DK37. In human myofibroblasts derived from a patient’s fibroblasts, emerin ∆K37 is correctly localized at the inner nuclear membrane, but is present at a significantly lower level, indicating that this mutant is abnormally degraded. Moreover, SUN2 is reduced, and cells are defective in producing actin stress fibers when grown on a stiff substrate and after cyclic stretches. Altogether, our data suggest that the main effect of mutation DK37 is to perturb emerin function within the LINC complex in response to a mechanical stress.
ARTICLE | doi:10.20944/preprints202201.0406.v1
Subject: Medicine & Pharmacology, Cardiology Keywords: Atrial Arrhythmia; ACHD; Congenital Heart Disease; AP-ACHD classification; Mortality; Morbidity
Online: 27 January 2022 (03:22:27 CET)
The implications of the adult congenital heart disease anatomic and physiological classification (AP-ACHD) for risk assessment have not been adequately studied. A retrospective cohort study was conducted using data from an ongoing national, multicentre registry of patients with ACHD and atrial arrhythmias (AA) receiving apixaban (PROTECT-AR study, NCT03854149). At enrollment, patients were stratified according to Anatomic class (AnatC, range I to III) and physiological stage (PhyS, range B to D). Follow-up was conducted between May 2019 and September 2021. The primary outcome was a composite of death from any cause, any major thromboembolic event, major or clinically relevant non-major bleeding, or hospitalization. Cox proportional-hazards regression modeling was used to evaluate the risks for the outcome among AP-ACHD classes. Over a median 20-month follow-up period, 47 of 157 (29.9%) ACHD patients with AA experienced the composite outcome. Adjusted hazard ratios (aHR) with 95% confidence intervals [CI] for the outcome in PhyS C and PhyS D were 1.84 (95% CI 0.73 to 4.61) and 7.88 (95% CI 1.54 to 40.41) respectively, as compared with PhyS B. The corresponding aHRs in AnatC II and AnatC III were 1.10 (95% CI 0.39 to 3.06) and 0.99 (95% CI 0.24 to 4.10) respectively, as compared with AnatC I. In conclusion, the PhyS component of the AP-ACHD classification was an independent predictor of net adverse clinical events among ACHD patients with AA receiving apixaban.