Idiopathic Atrial Fibrillation Research Articles

Electrophysiological properties of the atrial myocardium and cardiac conduction system in patients with atrial fibrillation and different comorbidity

BACKGROUND: Atrial fibrillation is a rhythm disorder that has a complex and not yet fully understood etiology and pathogenesis. Catheter ablation is the most effective method for rhythm control in atrial fibrillation patients. The effectiveness of catheter ablation differs in patients with various concomitant pathologies of the cardiovascular system. AIM: To study electrophysiological properties of atrial myocardium and cardiac conduction system during catheter ablation for atrial fibrillation in patients with different cardiovascular comorbidities. MATERIALS AND METHODS: Intraprocedural data obtained during primary catheter ablations in 151 selected patients with atrial fibrillation were retrospectively analyzed. The patients were divided into 3 groups based on the presence or absence of cardiovascular comorbid pathology: group 1 — patients with idiopathic atrial fibrillation, group 2 — patients with a combination of atrial fibrillation and isolated essential arterial hypertension, group 3 — patients with a combination of atrial fibrillation and ischemic heart disease. RESULTS: The ventricular rate in the patients with atrial fibrillation was significantly higher than the heart rate in the patients with sinus rhythm (102.6 ± 20.8 beats/min and 64.9 ± 11.9 beats/min, respectively; p 0.001). The rhythm frequency differed significantly in Group 1, Group 2 and Group 3 in sinus rhythm (61.2 ± 10.9 beats/min, 60.1 ± 8.8 beats/min and 57.2 ± 10.3 beats/min, respectively; р 0.001), and in atrial fibrillation (107 ± 15.8 beats/min, 89.9 ± 14.3 beats/min and 102 ± 12.5 beats/min, respectively; р 0.001). In the patients of all groups both in sinus rhythm and in atrial fibrillation, the heart rate increased after pulmonary vein isolation compared with the rate before ablation (p 0.001). In all groups, after isolation of the pulmonary veins, a statistically significant decrease in the frequency of atrial fibrillatory activity was noted compared to the baseline: by 72 imp/min (р 0.001) in group 1, by 49 imp/min (р 0.001) in group 2, and by 49 imp/min (р = 0.003) in patients of group 3. The frequency of fibrillatory activity after pulmonary vein isolation was comparable in the study groups (р = 0.45), both before and after surgery. In the patients without coronary artery disease, there was a significant decrease in the amplitude of atrial electrograms after ablation compared to preoperative values (р = 0.042 in group 1; p 0.001 in group 2). The effective refractory period of the atrial myocardium did not differ between the groups (235 ± 30.3 ms, 220.6 ± 25.6 ms and 231.2 ± 39.4 ms, respectively; р = 0.359). CONCLUSIONS: In the patients with atrial fibrillation, the presence of concomitant pathology of the cardiovascular system affects the electrophysiological properties of the myocardium and conduction system of the heart and their changes after pulmonary vein isolation. Additional research is needed to develop a personalized approach to the treatment of atrial fibrillation in patients with concomitant pathology of the cardiovascular system.

Intraoperative atrial rhythm changes during atrial fibrillation catheter ablation in patients with arterial hypertension and coronary artery disease

Atrial fibrillation is a rhythm disorder with an extensive etiology and not fully understood pathogenesis. Catheter ablation is an effective way to control the rhythm of atrial fibrillation. The results of catheter ablation differ in patients with various comorbidities of the cardiovascular system. Intraoperative changes in the atrial rhythm can be a criterion for the long-term effectiveness of the operation or determine the need for additional effects.Aim: To assess intraoperative changes in atrial rhythm during catheter ablation of atrial fibrillation in patients with concomitant pathology of the cardiovascular system.Methodology and research methods. The results of catheter ablation of 451 patients with paroxysmal and persistent atrial fibrillation were analyzed retrospectively for the period from 2016 to 2017. After clinical and anamnestic data analysis, 151 patients with primary isolation of the pulmonary veins were selected. Depending on the concomitant pathology of the cardiovascular system, patients were divided into 3 groups: group 1 – with idiopathic atrial fibrillation, group 2 – atrial fibrillation in combination with isolated essential arterial hypertension and group 3 – atrial fibrillation in combination with ischemic heart disease.Results. In patients with idiopathic atrial fibrillation, relief of atrial fibrillation with sinus rhythm preservation until the end of surgery was more often observed than in patients with ischemic heart disease (22% vs. 10,6%, р = 0,021). In patients with ischemic heart disease, typical atrial flutter was much more common and there was a need to perform radiofrequency ablation of the cavothricuspid isthmus in addition to isolation of the pulmonary veins (47,9% vs. 18,8% 1 Group 1, р = 0,005, and 24,7% in Group 2, р = 0,01).Conclusions. The concomitant pathology of the cardiovascular system in patients affects the dynamics of the atrial rhythm during catheter treatment of atrial fibrillation and may take into account the definition of intraoperative tactics.

Correlation of Plasma Adiponectin Levels and Adiponectin Gene Polymorphisms with Idiopathic Atrial Fibrillation

Introduction: Adiponectin is a cellular protein secreted by adipocytes, which is closely related to a variety of diseases, including atrial fibrillation (AF). Idiopathic atrial fibrillation (IAF) is defined as AF without hypertension, diabetes, and other underlying diseases. Genetic polymorphism of adiponectin affects serum adiponectin concentration. However, the association of serum adiponectin concentration and its genetic polymorphism with IAF has not been studied. This study investigated the relationship between serum levels of adiponectin, adiponectin gene polymorphisms, and the risk of developing IAF in a Chinese Han population. Methods: Patients with IAF (n = 172, IAF group) and healthy individuals (n = 150, control group) were consecutively and randomly recruited and fasting peripheral blood samples were collected. All participants were examined for serum adiponectin concentrations and the polymorphisms SNP45T>G (SmaI locus, rs2241766) and SNP276G>T (BsmI locus, rs1501299) of the adiponectin gene were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Related clinical data from the two groups were also collected. Results: Plasma adiponectin levels in the IAF group were significantly lower than those in the control group (9.9 ± 2.6 mg/L vs. 16.1 ± 7.0 mg/L, p = 0.006). There were no significant differences among the three genotypes (wild type, mutant heterozygote, and homozygote) of SNP45T>G or SNP276G>T in the prediction value of IAF. The frequency of the T allele of SNP45 T>G was 70.3% in the IAF group and significantly different from that of the control group (71.3%; p = 0.02). In the case of SNP276G>T, the frequency of the G allele was 68.61% in patients with IAF compared to 73.34% in the control group (p = 0.35). Furthermore, a comparison of the clinical data of individuals in the two groups revealed that the left atrial diameter (LAD) in patients in the IAF group was obviously higher than that in the control group (43.3 ± 6.7 mm vs. 37.9 ± 5.1 mm, respectively; p < 0.001). The left ventricular ejection fraction (LVEF) in the IAF group was obviously reduced than that in the control group (54.7 ± 11.9% vs. 60.2 ± 5.6%, respectively; p < 0.001). Conclusions: Low plasma adiponectin levels were significantly associated with IAF. Hypoadiponectinemia can thus serve as an important factor for the incidence of IAF. The genotypes of SNP45T>G and SNP276G>T in the adiponectin gene may not correlate with the occurrence of IAF. However, our results demonstrate that the T allele of SNP45T>G may be responsible for IAF development in the Chinese Han population.

Low plasma renin activity is associated with “Apparently” idiopathic atrial fibrillation

BackgroundPrevious studies have reported the direct or indirect relationship between the renin-angiotensin-aldosterone system (RAAS) and atrial fibrillation (AF). However, in patients with “apparently” idiopathic AF without possible external influence, whether RAAS is dysregulated at an early stage of AF and its relationship with the recurrence of AF after ablation have not been studied. MethodsThis single-center, prospective, case-control study included apparently healthy individuals with AF (the case group) or paroxysmal supraventricular tachycardia (PSVT, the control group) referred for catheter ablation at the same period. The primary outcome was RAAS activation in these two groups. The secondary outcome was the 1-year recurrence of AF after ablation. ResultsThis study included 51 “apparently” idiopathic AF and 91 patients with PSVT. A greater proportion of patients in the case group had plasma renin activity (PRA) levels < 1 ng/ml/h compared to the control group (25.5 % vs. 7.7 %, P = 0.003). PRA < 1 ng/ml/h was the only factor found to be associated with the diagnose of AF in both the univariate model (odds ratio [OR] 4.11, 95 % confidence interval [CI] 1.52–11.11, P = 0.005) and the model adjusted for age and sex (OR 3.98, 95 % CI 1.20–13.25, P = 0.024). A similar pattern was seen with paroxysmal AF. No significant difference in the components of RAAS was observed between 11 patients with the recurrence of AF and 40 without the recurrence at the 1-year follow-up. ConclusionsThis observational study revealed an association between low renin activity and the diagnosis of “apparently” idiopathic AF, particularly paroxysmal AF.

The prevalence of masked hypertension in patients with lone atrial fibrillation: a cross sectional analytical study

Atrial fibrillation (AF) is prevalent in individuals with essential hypertension (HTN). Masked hypertension occurs in up to 15% of the general population and is associated with adverse clinical outcome. The aim of the current study was to evaluate the prevalence of masked hypertension in apparently normotensive individuals with lone AF. A cross sectional analytical study performed at the Rabin Medical Center included all patients > 18 years who visited the emergency department (ED) in the years 2018–2021 with idiopathic AF, had normal blood pressure (BP) values during their ED visit and did not have a history of hypertension or current use of anti-hypertensives. Ambulatory blood pressure monitoring (ABPM) was performed in all eligible patients within 30 days from ED visit. Data collected included information from the ED visit and data extracted from the monitoring device. A total of 1258 patients were screened for eligibility, of which 40 were included in the analysis. The average age was 53.4 ± 16 years, 28 patients (70%) were males. Overall, 18 individuals (46%) had abnormal BP values according to the 2017 ACC/AHA guidelines for the diagnosis of hypertension. Of these, 12 had abnormal 24-h BP average (≥ 125/75 mmHg), one had isolated daytime abnormal average (≥ 130/80 mmHg) and 11 had isolated night time abnormal average (≥ 110/65 mmHg). Masked hypertension is prevalent in patients with lone AF without a diagnosis of HTN and performing ABPM in such individuals should be strongly considered.

Radiomic Phenotype of Periatrial Adipose Tissue in the Prognosis of Late Postablation Recurrence of Idiopathic Atrial Fibrillation.

Forty-three patients admitted for lone AF catheter ablation, who had undergone multispiral coronary angiography, were enrolled in the study. PAAT segmentation was performed using 3D Slicer application followed by extraction of 93 radiomic features. At the end of the follow-up period, patients were divided into 2 groups depending on the presence or absence of AF recurrence. 12 months of follow-up after catheter ablation, postablation AF recurrence was reported in 19 out of 43 patients. Of 93 extracted radiomic features of PAAT, statistically significant differences were observed for 3 features of the Gray Level Size Zone matrix. At the same time, only one radiomic feature of PAAT, Size Zone Non Uniformity Normalized, was an independent predictor of postablative recurrence of AF after catheter ablation and 12 months of follow-up (McFadden's R2=0.451, OR - 0.506, 95% CI: 0.331‒0.776, p<0.001). The radiomic analysis of periatrial adipose tissue may be considered as a promising non-invasive method for predicting adverse outcomes of the catheter treatment, which opens the possibilities for planning and correction of patient management tactics after intervention.

Evaluating subclinical left ventricular and left atrial dysfunction in idiopathic atrial fibrillation: A speckle-tracking based strain-analysis

ObjectiveA subset of patients with atrial fibrillation (AF) presents without established AF risk factors and normal left ventricular (LV) systolic function, called idiopathic AF (IAF). Traditionally, echocardiography derived LV dimensions and ejection fraction (EF) are used to exclude LV dysfunction in IAF, but their sensitivity is limited. Our objective is to evaluate the presence of subtle alterations in LV function despite normal LVEF in patients with IAF compared to healthy controls, using speckle-tracking echocardiography (STE) based global longitudinal strain (GLS). MethodsStandard transthoracic echocardiography was performed in 80 patients with IAF and 129 healthy controls. Patients with overt cardiac disease as well as known established AF risk factors were excluded. STE analysis was performed to assess GLS of the LV, and left atrial strain (LAS). ResultsLVEF was normal and comparable between patients with IAF and healthy controls (63 ± 4% for both groups; p = 0.801). Mean GLS was within normal limits for both groups but statistically significantly more negative in patients with IAF (−20.6 ± 2.5% vs. -19.7 ± 2.5%; p = 0.016), however not when indexed for ventricular cycle length (p = 0.784). No differences in LA volume or non-indexed LAS were seen in patients with IAF compared to healthy controls. ConclusionsIn this selected group of IAF patients, STE did not detect any overt LV or LA dysfunction compared to healthy controls. Thus, IAF occurred in these patients not only in the absence of established AF risk factors but also without evidence of ventricular or atrial dysfunction.

Isolated Atrial Fibrillation, Inflammation and Efficacy of Radiofrequency Ablation: Preliminary Insights Based on a Single-Center Endomyocardial Biopsy Study.

The aim of the study was to evaluate the inflammatory changes in the myocardium, based on endomyocardial biopsy (EMB) data in patients undergoing radiofrequency ablation (RFA) for idiopathic atrial fibrillation (AF). A total of 67 patients with idiopathic AF were enrolled in the study. Patients underwent the intracardiac examination, RFA of AF, and EMB with histological and immunohistochemical studies. The catheter-treatment effectiveness, and occurrence of early and late recurrences of atrial tachyarrhythmias, were assessed depending on the identified histological changes. Nine patients (13.4%) did not have any histological changes in the myocardium according to EMB. Fibrotic changes were detected in 26 cases (38.8%). Inflammatory changes according to the Dallas criteria were observed in 32 patients (47.8%). The follow-up period for patients averaged 19.3 ± 3.7 months. The effectiveness rates of primary RFA were 88.9% in patients with the intact myocardium, 46.2% in patients with fibrotic changes of varying severity, and 34.4% in patients with the presence of criteria for myocarditis. No early recurrence of arrhythmias was observed in patients with unchanged myocardia. The presence of inflammatory and fibrotic changes in the myocardium increased the rates of early and late arrhythmia recurrences and accordingly halved the effectiveness RFA of AF.

Comparative effectiveness of propafenone and aksaritmin for conversion of paroxysmal atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: None. Background Aksaritmin (the sum of nine deterpenoid alkaloids, including lappaconitini hydrobromidum) is an antiarrhythmic drug (conditionally belongs to the I C class) which is extracted from the roots and rhizomes of local plant - Aconitum septentrionale (tablet 25 mg). Purpose Evaluation of comparative effectiveness of propafenone (Pr) and aksaritmin (Aks) for conversion of atrial fibrillation (AF) in patients without/minimal structural heart disease (ejection fraction is more than 50%). Materials and methods The study included 60 patients (31 men), mean age - 55.3±11.9 y.o. The inclusion criteria for patients in the study were: hemodynamically stable symptomatic paroxysmal AF (mean duration–16.3±9.1 hours). On the day of admission, all patients underwent a test of the necessary biochemical blood parameters, electrocardiography, 24-hour ECG monitoring, transthoracic echocardiography. The patients were divided into two groups (they did not differ in the main clinical and anamnestic characteristics): 1-group (n=30), Pr was prescribed in dose 450-600 mg per os; 2-group (n=30), Aks was prescribed in dose 50 mg (in combination with beta-blockers (60%) in cases of tachysystole (≥ 140 b.p.m.)) per os. Statistical analysis was carried out by the STATISTICA 13. Results The main causes of AF in group 1 and group 2: hypertension - 17 (56.7%) and 16 (53.3%), chronic persistent myocarditis - 11 (36.7%) and 12 (40%), idiopathic AF - 2 (6.7%) and 2 (6.7%) patients, respectively. The anamnesis of AF averaged 17.3±3.8 months in gr 1 and 18.2±4.7 months in gr 2. Pr according to the above-described scheme ("pill in a pocket"), sinus rhythm was restored in 22 (73.3%) of 30 patients, and the mean time to restore the sinus rhythm was 4.12±3.87 hours from the start of therapy. At the same time, the effectiveness of Pr in patients with a paroxysm duration of less than 24 hours was 77.2% - in 17 patients out of 22, with a duration 24-48 hours it was 62.5% - 5 patients out of 8. Aks restored sinus rhythm in 21 (70%) out of 30 patients (χ2=0.082; p&amp;gt;0.05), and the mean restoring time of sinus rhythm was 4.63±4.33 hours from the start of therapy (p&amp;gt;0.05). At the same time, the effectiveness of Aks in patients with a paroxysm duration of less than 24 hours was 81.8% - in 18 patients out of 22 (χ2=0.140; p&amp;gt;0.05), with a duration of more than 24-48 hours it was 37.5%-3 patients out of 8 (χ2=1.000; p&amp;gt;0.05). Conclusion Pr and Aks practically did not differ in efficiency (73.3% and 70%, respectively) and in the time of relief (4.12±3.87 h and 4.63±4.33 h, respectively) of AF paroxysms. At the same time, Aks (including combination with beta-blockers) was more preferable for relief of AF with a duration of up to 24 hours-81.8% versus 77.2% (p&amp;gt;0.05), and propafenone for relief of AF with a duration of more than 24-48 hours-62.5% versus 37.5% (p&amp;gt;0.05). Aks is relatively new and promising drug for the treatment of patients with new onset paroxysmal AF.

Atrial Fibrillation and Heart Failure as the Onset of AL-Amyloidosis

Left ventricular hypertrophy, atrial fibrillation and chronic heart failure are often in the practice of a cardiologist. The etiology of these conditions is very important because the correct early treatment. We are presenting a case of a late diagnosis of amyloidosis in a 53-year-old man. Despite the complex therapy, the course of the disease was complicated by the development of bilateral pneumonia, sepsis, disseminated intravascular coagulation and the patient died. Autopsy confirmed the diagnosis of systemic AL-amyloidosis (type Kappa) with massive damage to the heart, kidneys, lungs, liver, spleen, adrenal glands, thyroid gland, pancreas, gastrointestinal tract, subcutaneous fatty tissue and arterial vessels of the bone marrow. Thus, screening for amyloidosis is necessary in idiopathic LV thickening, atrial fibrillation, and heart failure for timely intravital diagnosis and therapy.

Features of the expression of fibroblast growth factor in patients with idiopathic atrial fibrillation and verified myocarditis

Abstract Introduction Myocarditis and inflammatory changes in the myocardium can be one of the causes of the development and progression of atrial fibrillation (AF). The biomarker FGFβ is involved in the processes of angiogenesis, repair of heart tissues and stimulates fibroblasts. Purpose To assess the dynamics and to identify the relationship of fibroblast growth factor (FGFβ) expression and myocardial inflammatory diseases revealed by the results of histological examination of endomyocardial biopsy in patients with various forms of idiopathic AF. Methods Subjects were 40 patients (41.0±9.2 y.o.) with idiopathic AF, the arrhythmic history constituted 4.9±3.9 years. The patients were divided into 3 groups: 1–with paroxysmal AF (n=15), 2–persistent (n=12), 3–long-term persistent (n=13) depending on the form of AF. All patients underwent radiofrequency ablation (RFA) of the pulmonary veins and endomyocardial byopsy with histologic and immunohistochemical studies. In 1st group active lymphocytic myocarditis (ALM) were found in 40% patients (n=6); in 2d and 3d groups – 66.7% (n=8 in each gr.). All other patients showed signs of lymphocytic infiltration (LI). The serum levels of FGFβ determined all patients in prior to intervention (T1) and in 6 months after RFA (T2). Results Comparative analysis showed, in patients with morphologically verified ALM, the FGFb levels in 6 months after RFA in 1st gr. was significantly higher than in 3d gr. (p=0.036). In patients gr.1 with ALM the levels of FGFb was higher (at stages T1 and T2) than in patients with LI (p=0.055 and p=0.06, respectively). In 1st gr., a positive association between the levels of FGFb (T1) and the degree of activity of inflammatory processes caused in 6 months after RFA (R=0.95 p=0.005) were identified. In 1st gr., the relationship between the degree of activity of inflammatory processes and fibrotic changes (R=−0.77 p=0.009) and an association of FGFb with the value of cardiac ejection fraction was obtained (R=0.90 p=0.037). In 2d gr., strong correlations of FGFb with the degree of activity of inflammatory processes (R=0.79 p=0.019) and ejection fraction (RT1=0.73 p=0.039, RT2=0.96 p=0.0002) were revealed. In 3d gr., the FGFb levels was significantly higher in patients with LI than with ALM (14.74 [13.28; 14.80] and 6.92 [5.65; 9.90] pg/ml, respectively; p=0.048). In 3d gr., the severity of fibrotic changes was associated with FGFb expression (RT1=−0.73 p=0.041, RT2=−0.85 p=0.008). Conclusion The relationships of FGFb with the degree of activity of inflammatory processes in groups with paroxysmal and persistent AF were revealed. In patients with active lymphocytic myocarditis, the FGFb level was significantly higher in paroxysmal AF than in long-term persistent AF. Our study showed, increased expression of FGFb is associated with inflammatory processes of active lymphocytic myocarditis, and may be due to intense proliferation and differentiation of fibroblasts in paroxysmal AF. Funding Acknowledgement Type of funding sources: Public Institution(s). Main funding source(s): Cardiology Research Institute, Tomsk NRMC

Epicardial adipose tissue and nonvalvular atrial fibrillation

Abstract Background Several studies revealed the relationship between epicardial fat tissue (EF) and development of atrial fibrillation (AF). Though pathophysiological mechanisms are not clear enough, the anatomy and location EF as a part of visceral adiposity tissue could lead to proinflammatory and fibrotic changes in atrial myocardium. Purpose To evaluate the paracrine effects of EF and detect the association of tissue Doppler imaging (TDI) parameters, EF thickness by cardiac magnetic resonance tomography (CMR) and biochemical markers of fibrosis and inflammation in patients with nonvalvular AF without concomitant coronary artery disease. Methods Thirty-nine patients with idiopathic paroxysmal AF, normal or slightly enlarged left atria (LA) (mean LA diameter 4,5±0,6cm) were included. The mean age was 50,8±13,9 y.o., 19 (49%) were men. The absence of coronary lesions was confirmed by angiography in all cases. Besides standard ECG and ECHO, all patients underwent TDI and CMR with late gadolinium enhancement. EP thickness at anterior left ventricular (LV) wall was estimated by CMR. The myocardial fibrotic and proinflammatory biomarkers levels - matrix metalloproteinases (MMP-2, MMP-9), tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) were estimated. Kendall rank correlation coefficient was used. If the |τ| &amp;gt;Tcr, the correlation ranked as statistically significant. Results The epicardial fat thickness was associated with TIMP-1 plasma level (τ=0,71; Tcr=0,18) and MMP-9 (τ=0,65; Tcr=0,16). Among clinical factors weight was slightly associated with fat thickness (τ=0,33; Tcr=0,26). Besides, we found correlation of MMP-9, TIMP-1 with E/e' by TDI (τ=0,65; Tcr=0,16 and τ=0,56; Tcr=0,21, relatively); and with maximal systolic strain of lateral LV wall (τ=−0,37; Tcr=0,18 and τ=−0,44; Tcr=0,16, relatively) and interventricular septum (τ=−0,36; Tcr=0,18 and τ=−0,44; Tcr=0,16, relatively). Conclusion The epicardial fat thickness by CMR is significantly associated with myocardial fibrosis markers (MMP-9, TIMP-1) in patients with AF without structural heart disease. The increasing levels of MMP-9 and TIMP-1 are associated with LV local contractility disturbances by TDI in patients with AF. This association demonstrates the paracrine effect of EF, which could lead to atrial remodeling and formation AF substrate even in patients without valvular and ischemic heart disease and with normal or slightly enlarged LA Funding Acknowledgement Type of funding sources: None.

Efficacy of cryoablation in idiopathic and non-idiopathic atrial fibrillation patients.

Studies assessing the unicentric and prospective comparison of efficacy of cryoballoon pulmonary vein isolation in idiopathic and non-idiopathic atrial fibrillation (AF) patients are missing. The aim of this study was to compare a single procedural outcome in these subgroups of AF patients. Atotal of 208 patients with drug resistant AF were included in this study. Among them, 36 patients had idiopathic AF and 172 patients had non-idiopathic AF. The efficacy endpoint was freedom from any atrial arrhythmia lasting >30 s after a3-months blanking period. The freedom from atrial arrhythmias without antiarrhythmic drugs after 1 and 3 years of follow-up, respectively, was 85.2 % and 70.4 % in patients with idiopathic AF; and 64.6 % and 39.9 % in patients with non-idiopathic AF (p=0.021). Moreover, the success rate when analysing only paroxysmal AF patients after 1 and 3 years of follow-up, respectively, was 95.7 % and 82 % in patients with idiopathic AF; and 72.6 % and 47 % in patients with non-idiopathic AF (p=0.022). Asingle cryoballoon pulmonary vein isolation was more effective in preventing atrial arrhythmias relapses in idiopathic AF patients compared to non-idiopathic AF patients. The best efficacy outcomes were observed in patients with paroxysmal idiopathic AF (Tab. 5, Fig. 2, Ref. 25).

İdiyopatik Atriyal Fibrilasyonlu Erşkinlerin Çocuklarında P Dalga Dispersiyonu Varlığının Değerlendirilmesi

İdiyopatik Atriyal Fibrilasyonlu Erşkinlerin Çocuklarında P Dalga Dispersiyonu Varlığının Değerlendirilmesi

Physical rehabilitation in idiopathic paroxysmal atrial fibrillation

Physical rehabilitation a promising approach in the treatment of idiopathic paroxysmal atrial fibrillation which is a important medical problem. Study objective : To develop and scientifically substantiate reflexology and physical training methods for the treatment and prevention of regulatory functional cardiac disorders in idiopathic paroxysmal atrial fibrillation. Materials and methods . The study involved 90 patients with idiopathic atrial fibrillation (IAF), who were divided into 2 groups: 45 patients with adrenergic (AAFF) and 45 patients with vagotonic (VAFF) forms. The patients received a complex treatment consisting of reflexology and dosed walking. The treatment efficacy evaluation involved clinical, functional and instrumental examinations, psychological tests, psychophysiological stress-test, 24h ECG monitoring to identify the standard deviation of the normal-to-normal RR intervals (SDNN); echocardiography, high-definition oscillometry, and biochemical tests. Results . We found that the complex of reflexology and dosed walking in both groups produced an antiarrhythmic effect resulting in reliable normalization of the cardiovascular system autonomic regulation. Conclusions . The complex normalizes the heart rate autonomic regulation and hemodynamic parameters, improves the psychological and emotional state and the quality of life. The proposed treatment demonstrated high efficiency.

Cardiac Amyloidosis: Internist and Cardiologist Insight

Cardiac amyloidosis (amyloid cardiomyopathy) is a disease damage to the heart caused by extracellular amyloid deposition. In some cases, there may be local damage to the structures of the heart, for example, the atria; more often, heart damage is part of a systemic (generalized) pathology. Depending on the amyloid precursor protein, 36 types of amyloidosis are described, among which hereditary and acquired forms are distinguished. Cardiac amyloidosis is diagnosed 1) in the case of the amyloid infiltration in the myocardial bioptates or 2) in the case of non-cardiac amyloid deposition and the left ventricular wall thickening &gt;12 mm without arterial hypertension and other reasons. The heart is most often affected in AL-, ATTR-, AA-, AANF-types of amyloidosis. Cardiac amyloidosis should be considered in patients with a heart failure with an unclear etiology, especially with preserved left ventricular ejection fraction, refractory to treatment, with proteinuria and CKD 4-5, in patients with idiopathic atrial fibrillation and conduction disturbances, in patients with left ventricular wall thickening of unclear etiology, low ECG voltage, unexplained arterial hypotension and pulmonary hypertension. Screening for cardiac amyloidosis should include non-invasive methods such as electrophoresis and immunofixation of blood and urine proteins, the free light lambda and kappa chains of immunoglobulins, 99Tc-DPD scintigraphy, genetic testing (if hereditary variants of amyloidosis are suspected), as well as a histological examination of biopsy samples stained with Congo red and polarizing microscopy.

Concealed Coronary Atherosclerosis In Idiopathic Paroxysmal Atrial Fibrillation is Associated with Imminent Cardiovascular Diseases.

Previous research showed a significant difference in the presence of subclinical coronary artery disease (CAD) on cardiac CT angiography (CTA) between patients with idiopathic paroxysmal atrial fibrillation (iAF) versus a matched sinus rhythm population (iSR). Here we present 5-year follow-up data and the consequences of subclinical CAD on baseline CTA on the development of cardiovascular disease in iAF. In 99 iAF patients (who underwent CTA as part of work-up for pulmonary vein isolation) and 221 matched iSR controls (who underwent CTA for CAD assessment), the incidence of hypertension, diabetes and major cardiovascular events (MACCE) during follow-up was obtained. Multivariable Cox regression analysis was used to reveal predictors of incident cardiovascular disease in the iAF group. During a follow-up of 68±11 months, over one third of patients developed cardiovascular disease, with no difference between iAF and iSR (log-rank p=0.56), and comparable low rates of MACCE (4.0% vs 5.0%,p=0.71). Within the iAF group, age (HR1.12(1.03-1.20);p=0.006), left atrial diameter (HR1.16(1.03-1.31);p=0.01), Segment Involvement Score (total number of coronary segments with atherosclerotic plaque; HR1.43(1.09-1.89);p=0.01) and the number of calcified plaques on CTA (HR0.53(0.30-0.92);p=0.01) were independent predictors of incident cardiovascular disease. Subclinical coronary disease on CTA may be useful to identify the subset of patients with iAF that harbour concealed cardiovascular risk factors and need intensive clinical follow-up to ensure timely initiation of appropriate therapy once CV disease develops, including anticoagulation and vascular prophylactic therapy.

Association of actin-myosin interaction biomarkers and fibrosis with myocardial inflammatory changes in patients with idiopathic atrial fibrillation

Abstract Introduction Myocarditis and inflammatory changes in the myocardium are causes of the development and progression of atrial fibrillation (AF). Inflammatory processes may also lead to the development of fibrosis, electrical and structural myocardial remodeling, adversely affecting the effectiveness of interventional treatment. Purpose To assess the dynamics and to identify relationships between serum levels of tropomyosin I, myosin light chain kinase (MLCK), myosin heavy (MYH7) and light chains (CMLC), transforming growth factor (TGF-β1) and myocardial inflammatory changes in patients with idiopathic AF. Methods Subjects were 40 patients (41.0±9.2 y.o.) with idiopathic AF (arrhythmic history constituted 4.9±3.9 years). Paroxysmal AF (ParAF) was detected in 37% (n=15), persistent AF (PerAF)–30% (n=12), and long-standing persistent (LPerAF)–33% (n=13). All patients underwent radiofrequency ablation (RFA) of the pulmonary veins and endomyocardial byopsy with histologic and immunohistochemical studies. Depending on the results of histological study, the patients were divided into 2 groups: 1–with active lymphocytic myocarditis (ALM) (n=22); 2–with lymphocytic infiltration (IL) (n=18). Blood for biomarkers evaluation was collected prior to RFA and in 6 months after RFA. Results In patients with ALM levels of biomarkers significant differed depending on the form of AF. In patients with PerAF, the levels of MYH7, MLCK and tropomyosin I were significantly lower than in patients with ParAF (p&amp;lt;0.005). In 6 months the levels of MLCK, tropomyosin I, and CMLC significantly differed in patients with ALM depending on the form of AF (p&amp;lt;0.05). In patients with PerAF in the group 1, the concentrations of MYH7, CMLC, and tropomyosin I were lower, than the group 2 (p&amp;lt;0.05). In 6 months in patients with PerAF, the TGF-β1 levels also differed between groups 1 and 2 (Me: 24.09 and 40.34 ng/ml, p&amp;lt;0.05). The content of TGF-β1 before the RFA and in 6 months in patients with PerAF was associated with the development of infiltration in 6 months after RFA (R=0.696, p=0.025). In LPerAF patients we showed correlation between the content of TGF-β1 and the severity of fibrosis in 6 months after RFA (R=0.607, p=0.047). At LPerAF TGF-β1 content correlated with degree of fibrosis in 6 months after RFA (R=0.607, p=0.047). The relationship between the form of AF and the inflammatory changes were identified (r=0.32, p=0.049). Thus, in patients with LPerAF and PerAF, ALM was diagnosed in 69% and 50% of cases, while in patients with ParAF the frequency of ALM detection constituted 33%. Conclusion Our study showed that ALM was detected in 55% of patients, and IL–in 45% of cases. Significant differences in the levels of MYH7, MLCK, CLCK, tropomyosin I in patients with PerAF and various forms of inflammatory myocardial changes were revealed. The content of the TGF-β1 is reduced in ALM in patients with PerAFP. The incidence of ALM was higher in patients with long-term persistent AF. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): Cardiology Research Institute, Tomsk NRMC

Clinical efficacy of atrial fibrillation ablation depending on histological changes in the myocardium

There is a group of patients with so-called idiopathic atrial fibrillation (AF) without the causes of arrhythmia established by a standard examination. Aim. To study the effect of histological changes in the myocardium in patients with idiopathic AF on the effectiveness of ablation. Material and methods. The study included 101 patients with idiopathic AF All patients underwent ablation, during which a myocardial biopsy was performed. Depending on the results of intervention, 3 groups were formed: 1 — no AF within 12 months, 2 — recurrent arrhythmia within first 3 months of follow-up, 3 — recurrent arrhythmia after first 3 months of follow-up. To assess inflammatory changes and the severity of fibrosis, histological and immunohistochemical tests of myocardial biopsies were performed. Results . Histological criteria for lymphocytic myocarditis in group 1 observed in 47,5% of patients, in groups 2 and 3 in 27,3% and 25%, respectively. Infiltration of less than 7 cells per 1 mm 2 by CD3+ lymphocytes prevailed in group 3. The activity of inflammation in the studied groups did not significantly differ. The minimum severity of fibrosis was significantly less frequently recorded in group 1 than in group 2 and 3. Nonexpression of viral antigens in the first group was significantly less common than in the second and third groups. Moreover, the combination of expression of enterovirus VP1 and human herpesvirus 6 antigens was significantly more often recorded in the first group. Positive correlation was found between the expression of viral antigens and markers of endo- and myocardial fibrosis. Conclusion. The primary risk factor for recurrent arrhythmia was the initial stage of fibrosis, while inflammatory changes and viral infection were not risk factors. The presence of viral antigens in the myocardium had an indirect effect on the clinical outcome.

Atrial fibrillation in horses part 1: Pathophysiology

Atrial fibrillation (AF) is the most common clinically relevant arrhythmia in horses, with a reported prevalence up to 2.5%. The pathophysiology has mainly been investigated in experimental animal models and human medicine, with limited studies in horses. Atrial fibrillation results from the interplay between electrical triggers and a susceptible substrate. Triggers consist of atrial premature depolarizations due to altered automaticity or triggered activity, or local (micro)reentry. The arrhythmia is promoted by atrial myocardial ion channel alterations, Ca2+ handling alterations, structural abnormalities, and autonomic nervous system imbalance. Predisposing factors include structural heart disease such as valvular regurgitation resulting in chronic atrial stretch, although many horses show so-called ‘lone AF’ or idiopathic AF in which no underlying cardiac abnormalities can be detected using routine diagnostic techniques. These horses may have underlying ion channel dysfunction or undiagnosed myocardial (micro)structural alterations. Atrial fibrillation itself results in electrical, contractile and structural remodelling, fostering AF maintenance. Electrical remodelling leads to shortening of the atrial effective refractory period, promoting reentry. Contractile remodelling consists of decreased myocardial contractility, while structural remodelling includes the development of interstitial fibrosis and atrial enlargement. Reverse remodelling occurs after cardioversion to sinus rhythm, but full recovery may take weeks to months depending on duration of AF. The clinical signs of AF depend on the aerobic demands during exercise, ventricular rhythm response and presence of underlying cardiac disease. In horses with so-called ‘lone AF’, clinical signs are usually absent at rest but during exercise poor performance, exercise-induced pulmonary hemorrhage, respiratory distress, weakness or rarely collapse may develop.