This literature review looks at the current features left atrial appendage thrombosis in atrial fibrillation. Assesed morphologic and functional characteristics of the left atrial appendage as the risks of thrombosis. Viewed therapeutic options in anticoagulation therapy for the prophylactic and treatment of the left atrial appendage thrombosis.

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<p>This literature review looks at the efficacy of removing “dormant” atriovenous conduction, which can be identified by means of intravenous ejection of adenosine triphosphate following catheter isolation of pulmonary vein ostia in patients with atrial fibrillation. The incidence of detecting conduction “breakthroughs” in the ablation lines when carrying out drug tests after isolation of pulmonary veins, as well as the prognostic significance of this phenomenon for atrial fibrillation recurrence are evaluated. Also assessed are drawbacks and limitations of the studies looking at the possibility of improving the efficiency of catheter ablation of atrial fibrillation by combining the removal of “dormant” atriovenous conduction zones identified by adenosine triphosphate testing and the ablation of ganglionated plexi.</p><p>Received 10 April 2017. Accepted 23 October 2017.</p><p><strong>Funding:</strong> The study did not have sponsorship.</p><p><strong>Conflict of interest:</strong> Authors declare no conflict of interest.</p><p><strong>Author contributions</strong><br />Conception and study design: Y.S. Krivosheev, V.N. Kolesnikov.<br />Data collection and analysis: Y.S. Krivosheev, D.I. Bashta.<br />Drafting the article: Y.S. Krivosheev, A.A. Simonyan.<br />Critical revision of the article: V.N. Kolesnikov.<br />Final approval of the version to be published: Y.S. Krivosheev, D.I. Bashta, A.A. Simonyan, T.A. Myznikova, Z.A. Mishodzheva, V.N. Kolesnikov.</p><p> </p>

<p><strong>Background.</strong> Pulmonary vein isolation (PVI) is the gold standard of interventional atrial fibrillation (AF) treatment, however, it doesn't provide a stable clinical effect and durable PVI in the long-term follow-up due to reconnections within the ablation line. To increase the efficacy of surgery, modulation of the autonomic nervous system can be combined with pulmonary vein isolation.<br /><strong>Aim.</strong> The study was focused on the evaluation of efficacy of ganglionated plexi (GP) ablation combined with PVI, and intraoperative drug testing of dormant pulmonary vein conduction and exclusion of non-pulmonary vein triggers in patients with paroxysmal atrial fibrillation.<br /><strong>Methods.</strong> There hundred sixty-seven patients with paroxysmal AF scheduled for catheter ablation were initially screened. PVI was performed in all patients. After testing with adenosine triphosphate and isoprenaline for dormant conduction following PVI and exclusion of non-pulmonary vein triggers, 194 patients with a positive response to high-frequency stimulation in the main GP sites of the left atrium were randomized in two groups: PVI (group I, n = 97), PVI with anatomical GP ablation (group II, n = 97). To perform continuous ECG monitoring, 53 patients received implantable cardiac monitors. The primary endpoint of the study was the freedom from any atrial tachyarrhythmias after 12 months of follow- up as recorded by 24-hour Holter monitoring. The secondary endpoints included AF burden based on implantable cardiac monitors data and predictors of AF recurrences. The patients were followed 3, 6, 9, 12 months after the ablation procedure.<br /><strong>Results.</strong> The mean follow-up was 12.5±2.2 months. By the end of the follow-up, 79 (81.4%) patients in the PVI with GP ablation group and 58 (59.8%) patients in the PVI only group were free from any atrial tachyarrhythmia (р=0.0012; log-rank test, HR 0.41, 95% CI [0.23–0.72], р=0.002; Cox regression). Implantable cardiac monitors data revealed that AF burden was significantly lower in the PVI with GP group as compared with the PVI only group (14.8±1.7% and 5.4±0.7%,<br />р&lt;0.001). According to the multivariable regression analysis, the independent predictors of AF recurrences were AF duration and presence of diabetes mellitus, while GP ablation reduced the risk of AF recurrence by 61%.<br /><strong>Conclusion.</strong> Ganglionated plexi ablation combined with pulmonary vein isolation confirmed by testing dormant conduction and excluding non-pulmonary triggers provides higher efficacy in maintaining the sinus rhythm as compared with PVI only in patients with paroxysmal atrial fibrillation.</p><p>Received 17 July 2018. Revised 7 August 2018. Accepted 10 August 2018.</p><p><strong>Funding:</strong> The study did not have sponsorship.</p><p><strong>Conflict of interest:</strong> Authors declare no conflict of interest.</p><p><strong>Author contributions</strong><br />Conception and study design: Yu.S. Krivosheev, L.I. Vilenskiy, V.N. Kolesnikov<br />Data collection and analysis: Yu.S Krivosheev, D.I. Bashta, A.A. Simonyan<br />Drafting the article: Yu.S. Krivosheev, A.A. Simonyan, D.I. Bashta, S.Yu. Krasilnikova<br />Critical revision of the article: V.N. Kolesnikov<br />Final approval of the version to be published: Yu.S. Krivosheev, D.I. Bashta, A.A. Simonyan, S.Yu. Krasilnikova, L.I. Vilenskiy, T.A. Myznikova, Z.A. Mishodzheva, V.N. Kolesnikov</p>

<p><strong>Background.</strong> Catheter pulmonary vein isolation (PVI) is the main interventional procedure for treatment of atrial fibrillation (AF). Recurrences of arrhythmia paroxysms in the postoperative period are mainly determined by reconnection of conduction from the pulmonary veins. However, non-pulmonary vein triggers and a positive vagal response of ganglionated plexi (GP) to high frequency stimulation after PVI confirmed by drug testing may affect the long-term efficacy of catheter AF ablation.<br /><strong>Aim.</strong> To evaluate the efficacy of PVI isolation after drug testing and a negative response to high-frequency stimulation and a positive response to high-frequency stimulation but without subsequent ablation in patients with paroxysmal AF, as well as the efficacy of PVI confirmed by drug testing in patients having nonpulmonary vein triggers.<br /><strong>Methods</strong>. The present analysis is a part of the randomized study on the comparison of PVI confirmed by drug testing with the absence of non-pulmonary vein triggers and a positive response of GP to high-frequency stimulation with and without GP ablation. PVI was performed in 311 patients. Ninety-six patients were<br />excluded because they required additional GP ablation. Two hundred and fourteen patients were divided into three groups: PVI with a positive GP response (posGP) to high-frequency stimulation without GP ablation (group I, n = 97), PVI with a negative GP response (negGP) to high-frequency stimulation (group II, n = 79) and PVI with non-pulmonary vein triggers (group III, n = 38). The primary endpoint of the study was the freedom from any atrial tachyarrhythmias<br />after 12 months of follow-up confirmed by 24-hour Holter monitoring. The secondary endpoints included the frequency of detecting dormant pulmonary vein conduction, non-pulmonary vein triggers, negative GP response to high-frequency stimulation after catheter PVI. The patients were followed 3, 6, 9, 12 months after the ablation procedure.<br /><strong>Results</strong>. At the end of the follow-up 57 (72.2%) patients in the PVI + negGP group (group II), 58 (59.8%) patients in the PVI + posGP group (group I) and 20 (52.6%) patients in the PVI + NPT (group III) were free from any atrial tachyarrhythmia (р=0.07; log-rank test). A statistical significance in the efficacy was observed when group II was compared with group III (72.2% and 52.6%, р = 0.028, log-rank test). In the course of primary ablation following PVI, when performing drug testing, dormant atriovenous conduction sites were observed in 105 (33.8%) patients, while non-pulmonary vein triggers (n = 79) were recorded in 38 (12.2%) patients. The frequency of negative GP responses to high-frequency stimulation after PVI accounted for 28.3%.<br /><strong>Conclusion</strong>. Pulmonary vein isolation confirmed by drug testing, without a response of GP to high-frequency stimulation tends to provide higher efficacy in maintaining the sinus rhythm as compared with PVI and a positive GP response to high-frequency stimulation, but without a statistical significance, whereas nonpulmonary vein triggers after PVI are associated with lower efficacy in the long-term follow-up.</p><p>Received 31 July 2018. Revised 8 August 2018. Accepted 14 August 2018.</p><p><strong>Funding:</strong> The study did not have sponsorship.</p><p><strong>Conflict of interest</strong>: Authors declare no conflict of interest.</p><p><strong>Author contributions</strong><br />Conception and study design: Yu.S. Krivosheev, D.I. Bashta, V.N. Kolesnikov<br />Data collection and analysis: Yu.S. Krivosheev, D.I. Bashta, N.A. Tihonova<br />Drafting the article: Yu.S. Krivosheev, A.A. Simonyan<br />Critical revision of the article: V.N. Kolesnikov, K.V. Modnikov, T.A. Myznikova<br />Final approval of the version to be published: Yu.S. Krivosheev, D.I. Bashta, A.A. Simonyan, N.A. Tihonova, K.V. Modnikov, T.A. Myznikova, Z.A. Mishodzheva,<br />V.N. Kolesnikov</p>