Atrial fibrillation detection with long-term continuous Holter ECG recording in patients with high cardiovascular risk and clinical palpitations: the prospective after study.

AIM: New technologic tools for continuous ECG monitoring have been developed to detect and treat atrial fibrillation (AF) in specific populations with high cardiovascular risk. We evaluated the prevalence and the management of AF diagnosed in patients with high cardiovascular risk and non-documented clinical palpitation undergoing systematic 14-day continuous ECG-Holter monitoring. METHODS: Patients were prospectively enrolled from December 2019 to December 2021 in this multicentre study, sponsored by the French National College of Cardiology. Patients met the following criteria: CHA2DS2VASc score ≥ 2 in males and ≥ 3 in females and clinical palpitations without previously documented arrhythmia. Enrolled patients underwent a continuous 14-day Holter-ECG monitoring for arrhythmia detection. RESULTS: Among the 336 included patients, 39% were male, 75% were greater than 65 years of age and 46.5% had suffered a prior stroke. AF was detected in 14% of patients, among which 23.4% were detected in the first 24 h of monitoring. Finally, age ≥ 65 years (p = 0.037) was significantly associated with AF, as well as male gender (p = 0.023) and a lower rate of antiplatelet therapy (p = 0.018). Patients with diagnosed AF had a prescription of anticoagulation therapy in 90%. Antiarrhythmic drugs were administered in 90% of AF patients and 13% underwent AF ablation. CONCLUSIONS: The systematic AF screening of patients with palpitations and high cardiovascular risk resulted in a diagnostic yield of AF in 14% of the population with a 14-day continuous ECG-Holter monitor. This strategy resulted in the prescription of anticoagulation and antiarrhythmic therapy in 90% of the AF detected population.

Anti-inflammatory effects of endothelin receptor blockade in left atrial tissue of spontaneously hypertensive rats.

Objective: In spontaneously hypertensive rats (SHR) atrial remodeling has been shown to involve increase in endothelin (ET) signaling. Furthermore, inflammatory processes may further contribute to tissue remodeling. The aimed of this study was to investigate whether an endothelin receptor antagonist, macitentan, could reduce left atrial (LA) remodeling in arterial hypertension. Methods: Molecular characterization of atria was performed in SHR at the age of 8 months and their age-matched normotensive control rats (WKY). SHR were treated with macitentan and, for comparison with a blood pressure reducing drug, with doxazosin. After two months of treatment, molecules involved in endocardial inflammation and atrial calcium handling were assessed. The molecular changes provoked by rapid-pacing (RAP) were analyzed in atrial tissue slices. Results: Doxazosin reduced the systolic blood pressure compared with the untreated SHR (159 ± 26 vs. 176 ± 17; P < 0.05) or macitentan (vs. 189 ± 21; P < 0.05). Macitentan lowered the increased levels of atrial ET-1 and abrogated the pacing-induced upregulation of preproET-1-mRNA in atrial slices from SHR. Macitentan reduced the elevated levels of atrial 8-isoprostanes, the increased expression of pro-inflammatory ICAM-1 and IL-8, the phosphorylation of MAP kinases, ERK and p38, the phosphorylation of NF-κB and the expression of VCAM-mRNA. Major Ca2+-regulating proteins and markers of hypertrophy and fibrosis, however, were not affected. Doxazosin elicited similar changes, except for the alterations in ET-1 levels, NF-κB phosphorylation and VCAM-mRNA. Conclusion: Macitentan reversed pro-inflammatory remodeling in hypertensive atria in a blood pressure-independent manner, which might prevent endocardial dysfunction and thereby, thrombogenesis in arterial hypertension.

CREM-transgene mice: An animal model of atrial fibrillation and thrombogenesis.

BACKGROUND: The molecular pathomechanisms underlying atrial thrombogenesis are multifactorial and still require detailed investigations. Transgenic mice with cardiomyocyte-directed expression of the transcriptional repressor CREM-IbΔC-X (CREM-TG) represent an experimental model of atrial fibrillation (AF) that shows a gradual, age-dependent progression from atrial ectopy to persistent AF. Importantly, this model develops biatrial thrombi. The molecular characteristics related to the thrombogenesis in CREM-TG mice have not been studied, yet. METHODS: The inflammatory and prothrombotic state was evaluated at the transcriptional (qRT-PCR) and protein level in the left (LA) and right atria (RA) from CREM-TG mice at the age of 20weeks and compared to wild-type controls. Moreover, histological analyses of atrial thrombi were performed. RESULTS: The endocardial dysfunction was mirrored by diminished levels of eNOS-mRNA in both atria (RA: 0.79±0.04, LA: 0.72±0.06; each P<0.05). Moreover, the PAI-1/t-PA mRNA ratio was significantly increased in both atria (RA: 3.6±0.6; P<0.01, LA: 4.0±1.0; P<0.05) indicating a high risk of thrombus formation. However, the inflammatory phenotype was more pronounced in the RA and was reflected by a significant increase in the mRNA levels encoding adhesion molecules ICAM-1 (2.1±0.2; P<0.01), VCAM-1 (2.3±0.5; P<0.05), and selectin P (3.6±0.5: P<0.05). CONCLUSIONS: CREM-TG mice represent a valuable model for studying atrial thrombogenesis and assessing therapeutic approaches preventing embolic events in the systemic and pulmonary circulation.

Protective regulation of the ACE2/ACE gene expression by estrogen in human atrial tissue from elderly men.

Data from animal experiments and clinical investigations suggest that components of the renin-angiotensin system are markedly affected by sex hormones. However, whether estrogen affects human atrial myocardium has not been investigated yet. In this study, we determined the effects of estrogen on key components of atrial renin-angiotensin system: angiotensin-converting enzyme, responsible for generation of angiotensin II and angiotensin-converting enzyme 2, counteracting majority of AngII effects, and different renin-angiotensin system receptors, AT1R, AT2R, and MAS. First, the expression levels of estrogen receptors mRNA were determined in right atrial appendages obtained from patients undergoing heart surgery. The amounts of estrogen receptor α and estrogen receptor ß mRNA were similar between women ( n = 14) and men ( n = 10). Atrial tissue slices (350 µm) were prepared from male donors which were exposed to estrogen (1-100 nM; n = 21) or stimulated at 4 Hz for 24 h in the presence or absence of 100 nM estrogen ( n = 16), respectively. The administration of estrogen did not change mRNA levels of estrogen receptors, but activated MAP kinases, Erk1/2. Furthermore, estrogen increased the amounts of angiotensin-converting enzyme 2-mRNA (1.89 ± 0.23; P < 0.05) but reduced that of angiotensin-converting enzyme-mRNA (0.78 ± 0.07, P < 0.05). In addition, the transcript levels of AT2R and MAS were upregulated by estrogen. Pacing of tissue slices significantly increased the angiotensin-converting enzyme/angiotensin-converting enzyme 2 ratio at both the mRNA and protein level. During pacing, administration of estrogen substantially lowered the angiotensin-converting enzyme/angiotensin-converting enzyme 2 ratio at the transcript (0.92 ± 0.21 vs. 2.12 ± 0.27 at 4 Hz) and protein level (0.94 ± 0.20 vs. 2.14 ± 0.3 at 4 Hz). Moreover, estrogen elicited anti-inflammatory and anti-oxidative effects on renin-angiotensin system-associated downstream effectors such as pro-oxidative LOX-1 and pro-inflammatory ICAM-1. An antagonist of estrogen receptor α reversed these anti-inflammatory and anti-oxidative effects of estrogen significantly. Overall, our results demonstrated that estrogen modifies the local renin-angiotensin system homeostasis and achieves protective effects in atrial myocardium from elderly men. Impact statement The present study demonstrates that estrogen affects the human atrial myocardium and mediates protective actions through estrogen receptors-(ER) dependent signaling. Estrogen substantially modulates the local RAS via downregulation of ACE and simultaneous upregulation of ACE2, AT2R and MAS expression levels. This is indicative of a shift of the classical RAS/ACE axis to the alternative, protective RAS/ACE2 axis. In support of this view, estrogen attenuated the expression of RAS-associated downstream effectors, LOX-1, and ICAM-1. A specific antagonist of ERα reversed the anti-inflammatory and anti-oxidative effects of estrogen in paced and non-paced atrial tissue slices. In summary, our data demonstrate the existence of protective effects of estrogen in atrial tissue from elderly men which are at least in part, mediated by the regulation of local RAS homeostasis.

Atrial fibrillation and rapid acute pacing regulate adipocyte/adipositas-related gene expression in the atria.

PURPOSE: Atrial fibrillation (AF) has been associated with increased volumes of epicardial fat and atrial adipocyte accumulation. Underlying mechanisms are not well understood. This study aims to identify rapid atrial pacing (RAP)/AF-dependent changes in atrial adipocyte/adipositas-related gene expression (AARE). METHODS: Right atrial (RA) and adjacent epicardial adipose tissue (EAT) samples were obtained from 26 patients; 13 with AF, 13 in sinus rhythm (SR). Left atrial (LA) samples were obtained from 9 pigs (5 RAP, 4 sham-operated controls). AARE was analyzed using microarrays and RT-qPCR. The impact of diabetes/obesity on gene expression was additionally determined in RA samples (RAP ex vivo and controls) from 3 vs. 6 months old ZDF rats. RESULTS: RAP in vivo of pigs resulted in substantial changes of AARE, with 66 genes being up- and 53 down-regulated on the mRNA level. Differential expression during adipocyte differentiation was confirmed using 3T3-L1 cells. In patients with AF (compared to SR), a comparable change in RA mRNA levels concerned a fraction of genes only (RETN, IGF1, HK2, PYGM, LOX, and NR4A3). RA and EAT were affected by AF to a different extent. In patients, concomitant disease contributes to AARE changes. CONCLUSIONS: RAP, and to lesser extent AF, provoke significant changes in atrial AARE. In chronic AF, activation of this gene panel is very likely mediated by AF itself, AF risk factors and concomitant diseases. This may facilitate the development of an AF substrate by increasing atrial ectopic fat and fat infiltration of the atrial myocardium.

Update on management of cardiac arrhythmias in acute coronary syndromes.

This review summarizes different types of arrhythmias in patients with acute coronary syndromes and provides an overview of the available therapeutic options for acute care and management of critical arrhythmias. The different therapeutic options are depending on the origin and type of arrhythmia. The main common dominant mechanisms are intramural re-entry in ischemia and triggered activity in reperfusion. The different forms of arrhythmia were explained in detail. Atrial arrhythmias are mainly atrial fibrillation; other forms are rare and usually self-limited. As therapeutic options antiarrhythmic drug therapy with beta-blockers or amiodarone and direct current cardioversion are suitable. Ventricular arrhythmias can be divided in premature ventricular complexes, accelerated idioventricular rhythm, non-sustained ventricular tachycardia, sustained ventricular tachycardia (VT), ventricular fibrillation (VF) and electrical storm. As therapeutic options antiarrhythmic drug therapy, implantable cardioverter defibrillator therapy (ICD), radiofrequency catheter ablation (RFA) and stellate ganglion blockade are available. The treatment with antiarrhythmic drug is rather cautious recommended, with the exception of beta-blockers. An additional drug therapy with ranolazine may be considered. The advantage of ICD therapy for long-term primary or secondary prophylactic therapy has been well documented. ICD therapy is associated with significant reduction in mortality compared with antiarrhythmic drug therapy (mainly amiodarone), with the exception of beta-blockers. RFA and stellate ganglion blockade are rather intended as therapeutically options for incessant VT/VF or electrical storm.

[Bradycardic arrhythmias]. / Bradykarde Rhythmusstörungen.

Clinically symptomatic bradycardia arrhythmias due to disorders of impulse formation and conduction usually lead to an indication for pacemaker implantation. On the other hand, there are also a number of prognostic indications for pacemaker implantation in asymptomatic patients, but often with a lower class of recommendation. After acute myocardial infarction or cardiac surgery the implantation of a pacemaker may be necessary for the occurrence of bradycardia. Prior to a definitive pacemaker implantation reversible or preventable causes must be investigated and treated. Only for acute treatment of symptomatic bradycardia as a bridging measure drug therapy can be considered. For pacemaker supply various systems are available. We distinguish temporary from permanent systems and one-, two-and three-chamber systems. In addition, leadless pacemaker systems are tested.

[Bradycardic arrhythmias--part 1: pathophysiology and symptoms]. / Bradykarde Rhythmusstörungen. Teil 1: Pathophysiologie und Klinik.

Bradycardic arrhythmias are classified into disorders of impulse formation and conduction. Impulse formation disorders are diseases of the sinus node. Conduction disturbances are the sinoatrial (SA), atrioventricular (AV) block and bundle branch block. The conduction disturbances are also subdivided in different grades (grade I to III). Clinical manifestations of bradycardic arrhythmias are usually syncope, Morgagni-Adam-Stokes seizures, dizziness, palpitations, or heart failure. The investigation of syncope as the most visible clinical manifestation of bradycardic arrhythmias, is performed in three steps with the goal of risk stratification for sudden cardiac death or major adverse cardiac events. If symptomatic bradycardia is present, there is usually an indication for pacemaker implantation. Prior to a definitive pacemaker implantation reversible or preventable causes must be investigated and treated.

[Therapy of atrial fibrillation in the critically ill]. / Therapie des Vorhofflimmern beim kritisch Kranken.

Atrial fibrillation (AF) is the most common form of arrhythmia in the intensive care unit (ICU) and is associated with increased mortality. A total of five types of AF can be distinguished: initially diagnosed, paroxysmal, persistent, long-standing persistent and permanent AF. In addition to the initial treatment, antithrombotic therapy, rate and rhythm management can be used. The treatment of comorbidities is part of the patient management and for patients with increased risk of thromboembolic events anticoagulation is recommended. The simplest risk assessment scheme is the CHADS score. In the acute setting rate control is important. Direct current cardioversion is urgently recommended for patients with AF when hemodynamic instability is present even in patients with AF and pre-excitation in Wolff-Parkinson-White syndrome. Pharmacological cardioversion may be considered in patients with AF when hemodynamic stability is present. When choosing the antiarrhythmic agent for critically ill patients only amiodarone can be considered with some exceptions due to the specific contraindications.

Dronedarone prevents microcirculatory abnormalities in the left ventricle during atrial tachypacing in pigs.

BACKGROUND AND PURPOSE: Atrial fibrillation induces ischaemic microcirculatory flow abnormalities in the ventricle, contributing to the risk for acute coronary syndromes. We evaluated the effect of dronedarone on ventricular perfusion during rapid atrial pacing (RAP). EXPERIMENTAL APPROACH: Coronary and fractional flow reserve (CFR/FFR) were measured in the left anterior descending artery in 29 pigs. Six received RAP, six received RAP with dronedarone (RAP/D), seven received dronedarone alone, four received RAP with amiodarone (RAP/A), and six received neither (sham). In ventricular tissue, oxidative stress/ischaemia-related gene and protein expression was evaluated by RT-PCR and Western blotting; Isoprostanes were measured by GC-MS procedures. KEY RESULTS: CFR was decreased in the RAP group, compared with other groups. FFR was not different between groups. Effective refractory period was reduced in RAP compared with RAP/D. RAP-activated PKC phosphorylation tended to be decreased by dronedarone (P= 0.055) RAP induced NOX-1 and NOX-2 protein and the mRNA for hypoxia-inducible factor-1α (HIF-1α). Dronedarone reduced the pacing-dependent increase in the expression of NOX-2 protein and of HIF-1α mRNA. The oxidative stress marker, F(2)-isoprostane, was increased by RAP and this increase was attenuated by dronedarone. Other oxidative stress/ischaemia-related genes were induced by RAP compared with sham and were decreased by dronedarone treatment. In HL1 cells, dronedarone significantly inhibited the increased phosphorylation of PKCα after oxidative stress, with an almost significant effect (P= 0.059) on that after RAP. CONCLUSIONS AND IMPLICATIONS: Dronedarone abolished RAP-induced ventricular microcirculatory abnormalities by decreasing oxidative stress/ischaemia-related gene and protein expression in the ventricle.

Impact of the type of centre on management of AF patients: surprising evidence for differences in antithrombotic therapy decisions.

Atrial fibrillation (AF) patients may receive treatment from specialists or from general medicine physicians representing different levels of care within a structured health care system. This "choice" is influenced by patient flow within a health care system, patient preference, and individual access to health care resources. We analysed how the postgraduate training and work environment of treating physicians affects management decisions in AF patients. Patient characteristics and treatment decisions were analysed at the time of enrolment into the registry of the German Atrial Fibrillation NETwork (AFNET). A total of 9,577 patients were enrolled from 2004 to 2006 in 191 German centres that belonged to the following four levels of care: 13 tertiary care centres (TCC) enrolled 3,795 patients (39.6%), 58 district hospitals (DH) enrolled 2,339 patients (24.4%), 62 office-based cardiologists (OC) enrolled 2,640 patients (27.6%), and 58 general practitioners or internists (GP) enrolled 803 patients (8.4%). Patients with new-onset AF were often treated in DH. TCC treated younger patients who more often presented with paroxysmal AF. Older patients and patients in permanent AF more often received outpatient care. Consistent with recommendations, younger patients and patients with non-permanent AF received rhythm control therapy more often. In addition, the type of centre affected the decision for rhythm control. Stroke risk was similar between centre types (mean CHADS2 scores 1.6 -1.9). TCC (68.8%) and OC (73.6%) administered adequate antithrombotic therapy more often than DH (55.1%) or GP (52.0%, p<0.001 between groups). Upon multivariate analysis, enrolment by TCC or OC was associated with a 1.60 (1.20-2.12, p=0.001) fold chance for adequate antithrombotic treatment. This difference between centre types was consistent irrespective of the type of stroke risk estimation (ESC 2001 guidelines, CHADS2 score), and also consistent when the recently suggested CHA2DS2-VASc score was used to estimate stroke risk. In conclusion, management decisions in AF are influenced by the education and clinical background of treating physicians in Germany. Inpatients receive more rhythm control therapy. Adequate antithrombotic therapy is more often administered in specialist (cardiologist) centres.

[Techniques for occlusion of the left atrial appendage: chances and risks]. / Techniken zum Verschluss des linken Herzohres : Chancen und Risiken.

Atrial fibrillation causes 15-20% of ischemic strokes and the overall risk of stroke in patients with non-valvular atrial fibrillation is about 5% per year globally. Warfarin has long been the cornerstone for decreasing risks of stroke in patients with atrial fibrillation and its efficacy has been well established. However, 14-44% of patients with atrial fibrillation who are at risk of stroke are ineligible for anticoagulation therapy, mostly owing to the risks of major bleeding and falls. Occlusion of the left atrial appendage (LAA) appears to be an interesting new tool to prevent thromboembolic events in selected cases. In addition to surgical techniques, percutaneous transcatheter approaches have been introduced to occlude the LAA. Recent results indicate non-inferiority of mechanical occlusion of the LAA in comparison to warfarin therapy.

[Registry and studies of the German Competence Network on Atrial Fibrillation (AFNET)]. / Register und Studien des Deutschen Kompetenznetzes Vorhofflimmern (AFNET).

The German Competence Network on Atrial Fibrillation (AFNET) is a national interdisciplinary research network funded by the Federal Ministry of Education and Research (BMBF). AFNET was initiated in 2003 and aims at improving treatment of atrial fibrillation (AF), the most frequent sustained cardiac arrhythmia. AFNET has established a nationwide patient registry on diagnostics, therapy, course and complications of AF in Germany. The data analyzed to date demonstrate that patients with AF are likely to have multiple co-morbidities, such as hypertension, valvular heart disease, coronary artery disease, diabetes mellitus and advanced age. Oral anticoagulation is provided to the majority of patients in accordance with the recommendations given by guidelines. Further areas of research deal with the optimal duration of antiarrhythmic therapy following electrical cardioversion of atrial fibrillation and the value of strategies to prevent arrhythmogenic changes, such as fibrosis in the atria, for prevention of further episodes of atrial fibrillation. Additional registry projects were established for patients with catheter-based interventional therapy of atrial fibrillation and surgical ablation to define success, complications and long term results of these recently developed procedures more clearly. Data and insights gathered from these projects were used to further develop standards of care in two international conferences.

Rheumatoid pneumoconiosis (Caplan's syndrome).

In 1953, Caplan described a characteristic radiographic pattern in coal miners with rheumatoid arthritis (RA) that was distinct from the typical progressive massive fibrosis pattern of coalworkers' pneumoconiosis. It consists of multiple well-defined rounded nodules on chest X-ray, from about 0.5 to about several centimetres in diameter, distributed throughout the lungs but predominantly at the lung periphery. Lesions appear often in crops, may coalesce and form a larger confluent nodule. Nodules often cavitate or calcify. They typically occur in the setting of pre-existing mild pneumoconiosis, but pneumoconiosis is not a prerequisite. The onset of the nodules is typically sudden, and their course varies thereafter, ranging from regression to progression. Histologically, the nodules have a characteristic appearance and are distinguishable from silicotic nodules or progressive massive fibrosis. Individual susceptibility is considered to play a role in the development of the disease. However, the pathogenetic link between exposure to silica, pneumoconiosis and RA has not been clarified conclusively. This review summarizes history, definition and current knowledge on epidemiology, pathology, pathophysiology, clinical presentation and treatment of Caplan's syndrome.

[Current antiarrhythmic drug therapy in atrial fibrillation]. / Möglichkeiten und Grenzen der derzeitigen medikamentösen Behandlung von Vorhofflimmern.

Treatment strategies for atrial fibrillation (AF) encompass restoration and maintenance of sinus rhythm (rhythm control) or rate control. Antiarrhythmic drugs (AADs) currently recognized for this purpose are partially efficacious in maintaining sinus rhythm but are considered to have substantial cardiac or extra-cardiac toxicity. Yet so far, no endpoint trial has shown reduced morbidity or mortality using these agents. However, the ATHENA study was the first AF study conducted where morbidity and mortality were addressed investigating dronedarone as a new ADD therapy. This review summarizes the current pharmacological approaches to AF and briefly reviews the effects of new antiarrhythmic drugs for AF.

[Clinical profile of the new antiarrhythmic drug dronedarone]. / Klinisches Profil des neuen Antiarrhythmikums Dronedaron.

The new antiarrhythmic drug dronedarone (SR 33 589) is a benzofuran derivative structurally similar to amiodarone, however is noniodinated. The additional methansulfonylgroup renders it less lipophilic, with a substantially shorter half-life, compared to the parent compound. The electrophysiological properties of both agents are similar with inhibition of Na+, K+, and Ca++ currents (all Vaughan-Williams classes). The agent has been evaluated in a large clinical study program. The daily dose of dronedarone 800 mg has been shown (DAFNE) to be effective and well tolerated. In two design-identical randomised clinical trials (EURIDIS and ADONIS trial) the efficacy of dronedarone to maintain sinus rhythm in patients with chronic atrial fibrillation/flutter was shown to be clearly superior to placebo. The ERATO study showed the rate control properties of dronedarone. In the ATHENA morbidity/mortality study, the combined endpoint death or hospitalisation due to cardiovascular events occurred significantly less often in the dronedarone group compared to the placebo group. Particularly due to its beneficial effects on clinical outcomes such as cardiovascular hospitalizations and death in the context of high tolerability dronedarone appears to be a promising new antiarrhythmic compound.

[Clinical pharmacology and electrophysiological properties of dronedarone]. / Klinisch-pharmakologisches und elektrophysiologisches Profil von Dronedaron.

Dronedarone is a benzofuran derivative structurally similar to amiodarone but non-iodinated. The agent was systematically developed with the aim to maintain the antiarrhythmic potency of amiodarone while reducing the extracardiac side effects of the drug. Dronedarone is less lipophilic compared to the mother compound, which manifests in a substantial lower time to steady state (4-8 days compared to 1-3 weeks with amiodarone), and a more rapid elimination (half life 25-30 hours). Dronedarone has antiarrhythmic properties of all Vaughan-Williams classes. Among other channel blocking effects, It blocks sodium ion channels at higher stimulation frequency, prolongs the cardiac action potential, and has properties of a calcium channel blocker. Further, dronedarone has non-competitive antiadrenegic effects. No reverse use dependence has been documented at higher heart rate. These effects explain the antiarrhythmic and rate control properties of dronedarone in patients with atrial fibrillation.