Browsing by Author "Mujović, Nebojša (16234090000)"

BACKGROUND An incidental lesion of the parasympathetic ganglia during circumferential pulmonary vein isolation (CPVI) may affect heart rate variability (HRV). AIMS We studied the pattern of changes in HRV parameters and the relationship between the 1‑year HRV change following CPVI and the recurrence of atrial fibrillation (AF). METHODS A total of 100 consecutive patients undergoing CPVI for paroxysmal AF were enrolled (mean [SD] age, 56 [11.2] years; 61 men). We measured HRV on the day before and after CPVI, and then at 1 month as well as 3, 6, and 12 months after CPVI using 24‑hour Holter monitoring. RESULTS During the median follow‑up of 33 months, 38 patients experienced the late recurrence of AF (LRAF). Compared with the pre‑CPVI values, HRV was significantly attenuated on day 1 after CPVI in all patients. However, at 3 to 6 months after CPVI, all HRV parameters remained significantly decreased in LRAF‑free patients but not in those with LRAF. The multivariate Cox analysis showed that early AF recurrence within the blanking period (hazard ratio [HR], 4.87; 95% CI, 2.44–9.69; P <0.001) and a change in the standard deviation of normal‑to‑normal intervals (SDNN) observed 3 months after ablation (HR, 0.99; 95% CI, 0.98–1; P= 0.01) were associated with LRAF. The cumulative LRAF freedom after CPVI was greater in patients with an SDNN reduction of more than 25 ms reported 3 months after ablation than in those with a reduction of 25 ms or lower (log‑rank P = 0.004). CONCLUSIONS Sustained parasympathetic denervation during 12 months after CPVI was a marker of successful CPVI, whereas a 3‑month post‑CPVI SDNN reduction of 25 ms or lower predicted LRAF. Copyright by the Author(s), 2020.

Catheter ablation (CA) of atrial fibrillation (AF) is currently one of the most commonly performed electrophysiology procedures. Ablation of paroxysmal AF is based on the elimination of triggers by pulmonary vein isolation (PVI), while different strategies for additional AF substrate modification on top of PVI have been proposed for ablation of persistent AF. Nowadays, various technologies for AF ablation are available. The radiofrequency point-by-point ablation navigated by electro-anatomical mapping system and cryo-balloon technology are comparable in terms of the efficacy and safety of the PVI procedure. Long-term success of AF ablation including multiple procedures varies from 50 to 80%. Arrhythmia recurrences commonly occur, mostly due to PV reconnection. The recurrences are particularly common in patients with non-paroxysmal AF, dilated left atrium and the "early recurrence" of AF within the first 2–3 post-procedural months. In addition, this complex procedure can be accompanied by serious complications, such as cardiac tamponade, stroke, atrio-esophageal fistula and PV stenosis. Therefore, CA represents a second-line treatment option after a trial of antiarrhythmic drug(s). Good candidates for the procedure are relatively younger patients with symptomatic and frequent episodes of AF, with no significant structural heart disease and no significant left atrial enlargement. Randomized trials demonstrated the superiority of ablation compared to antiarrhythmic drugs in terms of improving the quality of life and symptoms in AF patients. However, nonrandomized studies reported additional clinical benefits from ablation over drug therapy in selected AF patients, such as the reduction of the mortality and stroke rates and the recovery of tachyarrhythmia-induced cardiomyopathy. Future research should enable the creation of more durable ablative lesions and the selection of the optimal lesion set in each patient according to the degree of atrial remodeling. This could provide better long-term CA success and expand indications for the procedure, especially among the patients with non-paroxysmal AF. © 2017, The Author(s).

Approximately 1 in 3–4 patients presenting with an ischemic stroke will also have atrial fibrillation (AF), and AF-related strokes can be effectively prevented using oral anticoagulant therapy (OAC), either with well-controlled vitamin K antagonists (VKAs) or non-vitamin K antagonist oral anticoagulants (NOACs). In addition, OAC use (both VKAs and NOACs) is associated with a 26% reduction in all-cause mortality (VKAs) or an additional 10% mortality reduction with NOACs relative to VKAs. The decision to use OAC in individual AF patient is based on the estimated balance of the benefit from ischemic stroke reduction against the risk of major OAC-related bleeding [essentially intracranial hemorrhage (ICH)]. Better appreciation of the importance of VKAs’ anticoagulation quality [a target time in therapeutic range (TTR) of ≥70%] and the availability of NOACs (which offer better safety compared to VKAs) have decreased the estimated threshold for OAC treatment in AF patients towards lower stroke risk levels. Still, contemporary registry-based data show that OAC is often underused in AF patients at increased risk of stroke. The uncertainty whether to use OAC may be particularly pronounced in AF patients with a single additional stroke risk factor, who are often (mis)perceived as having a “borderline” or insufficient stroke risk to trigger the use of OAC. However, observational data from real-world AF cohorts show that the annual stroke rates in such patients are higher than in patients with no additional stroke risk factors, and OAC use has been associated with reduction in stroke, systemic embolism, or death in comparison to no therapy or aspirin, with no increase in the risk of bleeding relative to aspirin. In this review article, we summarize the basic principles of stroke risk stratification in AF patients and discuss contemporary real-world evidence on OAC use and outcomes of OAC treatment in AF patients with a single additional stroke risk factor in various real-world AF cohorts. © 2016, The Author(s).

[No abstract available]

Background/Aim: Interatrial conduction time is early marker of disturbed impulse propagation in adult with elevated blood pressure. The aim of our study was to evaluate significance of noninvasive echocardiographic marker of slow sinus impulse propagation (atrial conduction time) for the identification of persons with slightly elevated blood pressure and hypertension in adults. Methods: One hundred and forty nine adults with normal and elevated blood pressure were studied: 46 normotensive adults (group 1), 28 adults with elevated blood pressure and hypertension stage 1 (group 2) and 75 adults with hypertension stage 2 (group 3), based on the Joint National Committee 8 (JNC-8) hypertension guidelines. We studied P wave dispersion, reservoir function of the left atrium (LA), total emptying volume of the LA and total emptying fraction of the LA (LATEF). The atrial conduction time (ACT) was evaluated by the pulsed tissue Doppler, and expressed as interatrial and intraatrial conduction time. Results: The LATEF decreased progressively from the group 3 (64.8 ± 4.4%) to the group 2 (59.8 ± 5.2%) and the group 1 (55.6 ± 7.3%) (p < 0.001). The P wave dispersion (55.1 ± 9.8 ms vs. 46.8 ± 3.1 ms vs. 43.1 ± 2.6 ms; p < 0.01) and intra ACT were significantly prolonged only in the group 3 compared to the other groups (22.7 ± 11.0 ms vs. 8.4 ± 4.7ms vs. 5.6 ± 2.4 ms, respectively; p < 0.001). Inter ACT significantly increased from the group 1 to the group 2 and the group 3 (15.6 ± 3.9 ms vs. 24.6 ± 5.7 ms vs. 50.4 ± 20 ms, respectively; p < 0.05). Using a cut-off level of 19.5 ms, inter ACT could separate adults in the group 2 from the group 1 with a sensitivity of 85%, and specificity of 89% [area under receiver operating characteristic (ROC) curve 0.911]. Conclusion: Prolonged ACT estimated with the tissue Doppler may be useful for identification persons with slighty elevated blood pressure, and hypertension stage 1. © 2020 Inst. Sci. inf., Univ. Defence in Belgrade. All rights reserved.

Introduction. Atrial fibrillation (AF) is the major cause of stroke, particularly in older patients over 75 years of age. European Society of Cardiology guidelines recommend chronic anticoagulation therapy in patients with atrial fibrillation if CHA2DS2-VASc score is ≥ 1 [CHA2DS2-VASc score for estimating the risk of stroke in patients with nonrheumatic AF consisting of the first letters of patients condition: C – congestive heart failure; H – hypertension; A2 – age ≥ 75 years; D – diabetes mellitus; S2 – prior stroke, transitory ischaemic attack (TIA) or thrombolism; V – vascular disease; A – age 65–74 years; Sc – sex category]. However, a significant number of patients have a high bleeding risk, or are contraindicated for chronic oral anticoagulation, and present a group of patients in whom alternative treatment options for thromboembolic prevention are required. Transcatheter percutaneous left atrial appendage closure (LAAC) devices have been recommended in patients with contraindications for chronic anticoagulant therapy. Case report. We present our first three patients with nonvalvular AF and contraindications for chronic anticoagulant therapy who were successfully treated with implantation of LAAC Watchman device in Catheterization Laboratory of the Clinic for Cardiology, Clinical Center of Serbia in Belgrade Conclusion. Our initial results with Watchman LAAC device are promising and encouraging, providing real alternative in patients with non-valvular AF and contraindication for chronic anticoagulant therapy and high bleeding risk. © 2017, Institut za Vojnomedicinske Naucne Informacije/Documentaciju. All rights reserved.

Introduction Atrioventricular (AV) junction ablation coupled with pacemaker implantation is an effective therapeutic option for rate control in atrial fibrillation (AF) and heart failure (HF). However, there is controversy regarding the long-term outcome of the procedure, since right ventricular stimulation can lead to left ventricular remodelling and HF. Objective The aim of the study was to determine a 5-year outcome of the procedure on survival, HF control and myocardial function in patients with HF and uncontrolled AF. Methods All patients with AF and HF who underwent AV-junction ablation with pacemaker implantation in our institution ere followed after the procedure. HF diagnosis was established if ≥2 of the following criteria were present: 1) ejection fraction (EF) ≤45%; 2) previous episode of congestive HF (CHF); 3) NYHA-class ≥2; and 4) use of drug-therapy for HF. Results Study included 32 patients (25 males; 53.4±9.6 years). The mean heart rate was 121±25 bpm before and 75±10 bpm after ablation (p=0.001). Over the follow-up of 5.0±4.0 years nine patients (28.1%) died (five died suddenly, three of terminal CHF and one of stroke). After the procedure, CHF occurrence was reduced (p=0.001), as well as the annual number of hospitalizations (p=0.001) and the number of drugs for CHF (p=0.028). In addition, NYHA-class and EF were improved, from 3.3±0.7 to 1.6±0.8 (p<0.001) and from 39±11% to 51±10% (p<0.001), respectively. Conclusion In HF patients with uncontrolled AF, 5-year mortality after AV-junction ablation and pacemaker implantation was 28%. In the majority of these patients good rate of AF and HF control were achieved, as well as the improvement of functional status and myocardial contractility.

Background/Aim. Atrioventricular nodal (AV) reentry tachycardia (AVNRT) is the most common form of supraventricular tachycardia. Treatment of choice is a catheter-ablation of the slow pathway of the AV node. The aim of the study was to present the outcomes of this procedure after ten years of follow-up. Methods. The catheter-ablation procedure was performed in 92 patients (30 men and 62 women, mean age 52.0 ± 13.3 years, range 19 to 76 years) with confirmed AVNRT during the electrophysiological examination, from 2007 to 2009. Out of these, 64 patients were followed-up for ten years by inviting them to clinical examinations regularly. The occurrence of AV block, arrhythmia and the use of antyarrhythmic drugs were the main outcomes of the ten-year follow-up. Multivariate logistic regression was applied to identify significant predictors of arrhythmia after a follow-up period. Results. The primary success of intervention was achieved in 91 (98.9%) patients. Third-degree AV block was registered in 1 (1.1%) patient after the intervention, which required the implantation of a pacemaker. After ten years of follow-up, AVNRT relapses were not registered. A total of 7 out of 64 (10.9%) patients died during the follow-up period, mostly due to non-cardiac causes. After ten years of follow-up, first-degree AV block was registered in six (10.5%) patients, whereas other arrhythmias were observed in 17 (29.8%) patients such as atrial fibrillation or flutter, atrial premature beats and sinus tachycardia. The number of antiarrhythmic drugs were reduced from 2.1 ± 1.2 at baseline to 0.5 ± 0.6 during follow-up, mostly beta-blockers, propafenone and amiodarone, and 33 (57.9%) patients were no longer using anti-arrhythmic therapy. Logistic regression identified participant’s age above 55 years at baseline and re-intervention performed after the initial catheter-ablation as significant predictors of arrhythmia after a 10-year follow-up, independent from gender and arterial hypertension at baseline. Conclusion. The catheter-ablation of AVNRT represents a successful and safe procedure, from the perspective of ten-year follow-up. © 2020 Inst. Sci. inf., Univ. Defence in Belgrade. All rights reserved.

Introduction: Cardiac tamponade (CT) is a life-threatening complication of radiofrequency ablation (RFA). The course and outcome of CT in low-to-medium volume electrophysiology centers are underreported. Methods: We analyzed the incidence, management and outcomes of CT in 1500 consecutive RFAs performed in our center during 2011–2016. Results: Of 1500 RFAs performed in 1352 patients (age 55 years, interquartile range: 41–63), 569 were left-sided procedures (n = 406 with transseptal access). Conventional RFA or irrigated RFA was performed in 40.9% and 59.1% of procedures, respectively. Ablation was performed mostly for atrioventricular nodal reentrant tachycardia (25.4%), atrial fibrillation (AF; 18.5%), atrial flutter (18.4%), accessory pathway (16.5%) or idiopathic ventricular arrhythmia (VA; 12.3%), and rarely for structural VA (2.1%). CT occurred in 12 procedures (0.8%): 10 AF ablations, 1 idiopathic VA and 1 typical atrial flutter ablation. Factors significantly associated with CT were older age, pre-procedural oral anticoagulation, left-sided procedures, transseptal access, AF ablation, irrigated RFA and longer fluoroscopy time (on univariate analysis), and AF ablation (on multivariable analysis). The perforation site was located in the left atrium (n = 7), right atrium (n = 3), or in the left ventricle or coronary sinus (n = 1 each). Upon pericardiocentesis, two patients underwent urgent cardiac surgery because of continued bleeding. There was no fatal outcome. During the follow-up of 19 ± 14 months, eight patients were arrhythmia free. Conclusion: Incidence of RFA-related CT in our medium-volume center was low and significantly associated with AF ablation. The outcome of CT was mostly favorable after pericardiocentesis, but readily accessible cardiothoracic surgery back-up should be mandatory in RFA centers. © 2016, The Author(s).

[No abstract available]

Background: Data on the roof line (RL) and mitral isthmus line (MIL) reconnections after atrial fibrillation (AF) catheter ablation (CA) are scarce. Objective: We studied the RL and MIL completeness and localization of reconnection sites in consecutive patients after their first-ever AF-CA. Methods: We prospectively included 41 consecutive AF patients who underwent predefined lesion sets of two circumferential lines (CLs) for ipsilateral pulmonary vein isolation (PVI) combined with a RL and lateral MIL. Three months after CA, all patients underwent invasive follow-up procedure for line persistency evaluation, irrespective of clinical outcome. Results: At the time of index ablation, PVI-CLs, RL, and MIL was completed in 41 (100%), 39 (95%), and 34 (83%) of patients, respectively. At the 3-month follow-up procedure, reconnections of PVI-CLs, RL, and MIL were found in 61% (25/41), 28% (11/39), and 24% (8/34) of patients, respectively. The 3-month reconnections were located commonly in the anterior and posterior PVI-CL segments, and rarely in the right third of RL and in the posterior part of MIL. The 3-month reconnections were rarely seen at the sites of acute reconnections during index procedure (6%, 20%, and 25% of the PVI-CL segments, RL segments, and MIL segments, respectively). Conclusions: To our knowledge, this is the first study systematically investigating the reconnection of standardized left atrium linear lesions such as RL and MIL after RF-CA for AF in consecutive patients. The RL and MIL 3-month reconnection rates were relatively low (28% and 24%), with poor anatomical concordance between the sites with acute and 3-month reconnections. © 2017 Wiley Periodicals, Inc.

[No abstract available]

[No abstract available]

Introduction: Large population-based observational trials have shown atrial fibrillation (AF) to be an independent risk factor for increased mortality. Objective: To examine all-cause mortality and cardiovascular mortality of patients with AF compared to corresponding mortality in general population of Serbia. Methods: This longitudinal observational study included patients with nonvalvular AF as the main indication for in-hospital and/or outpatient treatment at the Clinical Centre of Serbia, Belgrade, during the period 1992-2007, if the latest date of the first diagnosed AF was early January 2003, so that the total follow-up could last at least 5 years (minimum 1 year prospectively), or until death. Patients with acute causes of AF, advanced left ventricular systolic dysfunction (LVEF≤25%), preexcitation, known malignancy or any advanced chronic disease and patients with poorly documented history of previous AF were not included. To compare mortality of study population with mortality of general population, we used standardized mortality ratio (SMR) and chi-square test, p<0.05. Results: Out of 1,100 patients (389 females, 35.4%), aged 52.7±12.2 years, with total follow-up 9.94±6.05 years (prospective 5.75±4.28, retrospective 4.21±5.51), 40% had no underlying disease; others most frequently had arterial hypertension. AF was paroxysmal in 665 (60.5%), persistent in 225 (20.5%) and permanent in 210 patients (19.1%). Newly diagnosed AF was documented in 1058 patients (96.2%). Until the end of the study, 85 patients died (7.7%). Cardiovascular death was noted in 62 patients (72.9%), most frequently in form of sudden death (27/85, 31.7%), death from congestive heart failure (18/85, 21.2%) and stroke (14/85, 16.5%). Most patients (67/85, 78.8%) had AF at the time of death. SMR for all-cause mortality was 2.43 (p<0.0001) and for cardiovascular mortality 3.03 (p<0.0001). Conclusion: All-cause mortality and cardiovascular mortality of AF patients are higher than corresponding mortality in general population of Serbia, despite active treatment.

Modifiable risk factors, such as cardiometabolic and lifestyle risk factors, considerably contribute to (bi)atrial remodeling, finally resulting in clinical occurrence of atrial fibrillation (AF). Early identification and prompt intervention on these risk factors may delay further progression of atrial arrhythmia substrate and prevent the occurrence of new.onset AF. Moreover, in patients with previous history of recurrent AF, aggressive risk factor management may improve efficacy of other rhythm control strategies, including antiarrhythmic drugs and catheter ablation in sinus rhythm maintenance. Finally, modification of risk factors improves overall health and reduces cardiovascular mortality and morbidity. The first part of this review evaluates the association between AF and the following risk factors: hypertension, diabetes mellitus, physical activity, and cigarette smoking. We systematically discuss the impact of risk factor modification on primary and secondary prevention of AF. © 2020 by the Author(s).

Atrial fibrillation (AF) is the most common cardiac arrhythmia and is associated with increased risk of death, stroke, and heart failure. Prevalence and incidence of AF are rising due to better overall medical treatment, longer survival, and increasing incidence of cardiometabolic and lifestyle risk factors. Treatment of AF and AF-related complications significantly increases healthcare costs. In addition, the use of conventional rhythm control strategies (including, antiarrhythmic drugs and catheter ablation) is associated with limited efficacy for sinus rhythm maintenance and serious adverse effects. Aggressive cardiometabolic risk factor management may prevent incident as well as recurrent AF, improve overall health, and reduce mortality. Therefore, modifiable risk factor management became one of the 3 treatment pillars in AF management along with anticoagulation as well as conventional rate and rhythm control strategies. The second part of this review systematically discusses the association between AF and potentially modifiable risk factors for AF, such as obesity, obstructive sleep apnea, alcohol consumption, and dyslipidemia. We also provide practical guidelines for the risk factor management with respect to primary and secondary prevention of AF. © 2020 by the Author(s).