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Background and Objectives : Atrioventricular (AV) dyssynchrony as well as atrial and ventricular pacing affect left atrial (LA) function. We conducted a study evaluating the effect of atrial and ventricular pacing on LA morphological and functional changes after dual-chamber pacemaker implantation. Materials and Methods : The study prospectively enrolled 121 subjects who had a dual-chamber pacemaker implanted due to sinus node disease (SND) or atrioventricular block (AVB). Subjects were divided into three groups based on indication and pacemaker programming: (1) SND DDDR 60; (2) AVB DDD 60 and (3) AVB DDD 40. Subjects were invited to one- and three-month follow-up visits. Three subsets based on pacing burden were analyzed: (1) high atrial (A) low ventricular (V); (2) high A, high V and (3) low A, high V. LA function was assessed from volumetric parameters and measured strains from echocardiography. Results : The high A, low V group consisted of 38 subjects; while high A, high V had 26 and low A, high V had 23. A significant decrease in reservoir and contractile LA strain parameters were only observed in the high A, low V pacing group after three months (reservoir 25.9 ± 10.3% vs. 21.1 ± 9.9%, p = 0.003, contractile -14.0 ± 9.0% vs. -11.1 ± 7.8, p = 0.018). While the re-established atrioventricular synchrony in the low A, high V group maintained reservoir LA strain at the baseline level after three months (21.4 ± 10.4% vs. 22.5 ± 10.4%, p = 0.975); in the high A, high V group, a further trend to decrease was noted (20.3 ± 8.9% vs. 18.7 ± 8.3%, p = 0.231). Conclusions : High atrial pacing burden independently of atrioventricular dyssynchrony and ventricular pacing impairs LA functional and morphological parameters. Changes appear soon after pacemaker implantation and are maintained.

Long QT syndrome (LQTS) is majorly an autosomal dominantly inherited electrical dysfunction, but there are exceptions (Jervell and Lange-Nielsen syndrome is inherited in an autosomal recessive pattern). This disorder prolongs ventricular repolarization and increases the risk of ventricular arrhythmias, syncope, and even sudden cardiac death. The risk of fatal events is reduced during pregnancy, but dramatically increases during the 9 months after delivery, especially in patients with LQT2. In women with LQTS, treatment with β-blockers at appropriate doses is recommended throughout pregnancy and the high-risk postnatal period. In this review, we summarize the management of LQTS during pregnancy and beyond.

Background and Objectives : Chronic atrial stimulation might impair left atrial (LA) function. We aimed to assess the impact of atrial pacing burden on LA volumetric and functional parameters after implantation of a dual-chamber pacemaker. Materials and Methods : The prospective study included 121 subjects with sinus node disease (SND) or atrioventricular block (AVB) that received a dual-chamber pacemaker. After device implantation, the subjects were divided into three groups: (1) SND with a lower rate (LR) set to 60 bpm and rate response enabled; (2) AVB with an LR set to 60 bpm and no rate response; and (3) AVB with an LR set to 40 bpm and no rate response. Subjects were followed at one and three months. Two subsets of patients with high and low atrial pacing burdens accompanied by low ventricular pacing percentage were analyzed. LA function was evaluated with volumetric and strain parameters from transthoracic echocardiography. Results : The high atrial low ventricular pacing group consisted of 38 subjects, and the low atrial low ventricular group consisted of 22 subjects. When looking at the change in volumetric parameters, we observed a tendency for volumes to increase in both groups; however, only minimal LA volume reached statistical significance at three months in the high atrial pacing group. A trend towards the lowering of an active emptying fraction at one month ( p = 0.076) became significant at three months ( p = 0.043), and was also only observed in the same group. Moreover, a decrease in the tendency to reach statistical significance at three months for reservoir and contractile strain parameters and stiffness index was only observed in the high atrial pacing group. Meanwhile, in the low atrial pacing burden group, all parameters remained significantly unchanged. Conclusions : The burden of right atrial pacing in patients with preserved left ventricular function negatively influences functional and morphologic LA parameters. Moreover, negative effects take place soon after pacemaker implantation and appear to be sustained.

We present a special case of fetal supraventricular tachycardia detected at 34 weeks gestation. Fetal hydrops was noted on ultrasound upon admission. Normal fetal heart rate was maintained for three weeks by maternal administration of digoxin. A live infant was delivered via caesarian section at 37 weeks gestation. This clinical case demonstrated that pharmacological treatment can be effective and helps to prolong pregnancy safely.

Objectives: The aim of the study was to study some anatomic and electrophysiological features of the right atrium, related to the presence of atrial flutter., Materials and Methods: A total 23 patients with type I atrial flutter and 22 patients without atrial flutter were studied. Right atrium size was assessed using echocardiography before intracardiac examination and radiofrequency ablation., Results: Effective refractory periods of coronary sinus, high right atrium, low right atrium were different comparing with the control group (P<0.05). A stimulus-response time between high right atrium and low right atrium positions in anterograde and retrograde ways, an impulse propagation speed along the lateral wall of the right atrium were statistically different comparing both groups (P<0.05). There was a significant correlation among effective refractory periods measured in different sites of the right atrium (r2=0.64, 0.44, 0.44, respectively). All measured effective refractory periods also correlated with stimulus-response time in anterograde way (P<0.05) and impulse propagation speed (P<0.05). Right atrium dimensions were significantly larger in atrial flutter group. There was no correlation between the right atrium dimensions and measured electrophysiological parameters in both groups., Conclusions: The presence of atrial flutter associates with diffuse alterations of the right atrium, but not the focal or single changes of refractoriness.

Unlabelled: Idiopathic ventricular tachycardia is a rare condition, and there is a lack of clear guidelines for the necessity and indications for prophylactic antiarrhythmic or curative treatment. The aim of this study was to review the clinical picture of idiopathic ventricular tachycardia and evaluate the efficacy and safety of radiofrequency ablation therapy in children., Material and Methods: The subjects of this study were 16 children with idiopathic ventricular tachycardia. The mean age at onset of idiopathic ventricular tachycardia was 12 years. All patients underwent electrophysiological examination. Nonfluoroscopic mapping technology (Carto) was used in one case. Radiofrequency ablation was performed in all children (mean duration of follow-up was 46 months)., Results: Six children with idiopathic ventricular tachycardia were free of symptoms. Palpitation was the only complain in four patients, and six patients presented with symptoms of circulatory disorder (the tendency of the higher rate of ventricular tachycardia and more premature contractions and episodes of ventricular tachycardia in one day were noticed in five of them). All children after radiofrequency ablation were alive, and only one complication (complete right bundle branch block) occurred. Success at last follow-up included five children with left and six with right idiopathic ventricular tachycardia., Conclusions: Catheter ablation seems a promising therapeutic option with the outlook possible of the idiopathic ventricular tachycardia in children. It is safe enough and should be considered as the therapy of choice even in children without of symptoms if they wish to live active social and physical life.

Objective: To find out if radiofrequency ablation as method of treatment of cardiac arrhythmia influences platelet aggregation and if intensity of this process depends on the number of radiofrequency ablation episodes for one patient., Material and Methods: We analyzed platelet aggregation before, right after and in 24 hours after radiofrequency ablation in whole blood and platelet rich plasma in 39 cases with cardiac arrhythmias. Adenosine diphosphate and adrenaline were used for aggregation induction. Three groups of patients were formed based on the number of radiofrequency ablation episodes: A-- <10, B--10-20, C-- >20 for one patient., Results: We detected a decrease in spontaneous, adenosine diphosphate and adrenaline induced platelet aggregation in plasma right after radiofrequency ablation, and also the same tendency was noted in adenosine diphosphate induced aggregation in whole blood. In 24 hours after radiofrequency ablation platelet aggregation tended to return to pre-radiofrequency ablation levels. Based on the number of radiofrequency ablation episodes we detected significant changes in spontaneous and adrenaline-induced aggregation in plasma. In group A adrenaline induced aggregation after radiofrequency ablation increased by 0.4%, in group B it decreased by 15.7% and in group C it decreased by 19.4% from pre-radiofrequency ablation level (p<0.05, between groups A and C). Spontaneous platelet aggregation after radiofrequency ablation decreased in group A 41.9%, in group B--20.8% and in group C--18.4% from pre-radiofrequency ablation level (p<0.05 between groups A and C). The greater decrease in adenosine diphosphate induced aggregation in plasma and in whole blood was detected in the group with larger number of radiofrequency ablation episodes., Conclusions: This study found that platelet aggregation decreased in plasma and in whole blood after radiofrequency ablation. And this alteration was significant in groups B and C, when the number of radiofrequency ablation episodes were >10. In 24 hours platelet aggregation increased again to pre- radiofrequency ablation level.

One of the fundamental questions in the management of atrial fibrillation is whether cardioversion should be attempted. Studies have compared rate control with rhythm control strategies. Rhythm control has not been shown to be superior to rate control (with chronic anticoagulation) in reducing morbidity and mortality and may be inferior in some patient subgroups to rate control. Whether these results can be extrapolated to longer time periods than the trial duration (approximately 3.5 years) is not known. The purpose of this article is to discuss some important aspects of atrial fibrillation and to review recent developments in the management of this condition.