Atrial fibrillation therapy and stroke prevention in hemodialysis patients

The prevalence of atrial fibrillation (AF) in patients with chronic kidney disease (CKD), especially on hemodialysis (HD) is higher compared to the general population without CKD and reaches ~20%. The risk of ischemic stroke in CKD patients is also significantly increased. However, since the risk of bleeding is also significantly increased in CKD patients and the number of bleeding events exceeds the number of thrombotic events, there are great concerns regarding the routine use of anticoagulation in this patient population. No randomized studies were performed to compare anticoagulation with placebo in patients with advanced CKD and AF. This lack of knowledge is reflected in international guidelines which refrain from clear recommendations. The use of anticoagulation for stroke prevention in HD patients with AF should be strictly individualized for each patient. Anticoagulation for stroke prevention in HD patients with AF seems justified only in selected patients with high stroke and low bleeding risk. Reduced-dose direct oral anticoagulants (especially apixaban) may prove beneficial. In patients with high thrombotic and bleeding risk, left atrial appendage closure could be considered. In this article, the results of the most relevant observational studies with anticoagulation in CKD/HD patients with AF have been presented and discussed. Furthermore, results of randomized studies comparing vitamin K antagonists with non-vitamin K antagonists in CKD patients have been discussed in detail. Finally, ongoing randomized studies with reduced doses of apixaban, factor XI inhibitors, and left atrial appendage closure in CKD patients are mentioned. A brief summary of rhythm control strategies in AF is given

SPECTRAL ANALYSIS OF ATRIAL COMPONENTS OF ABLATION CATHETER SIGNALS DURING SLOW PATHWAY ABLATION FOR TYPICAL ATRIOVENTRICULAR NODAL REENTRANT TACHYCARDIA

Ablation of the slow pathway is the treatment standard for typical atrioventricular nodal reentrant tachycardia (AVNRT). However, the risk of complete heart block due to ablation of the fast pathway remains approximately 1%. Spectral analysis of the atrial components of ablation catheter signals during slow pathway ablation can provide additional information for precisely defining ablation sites. A retrospective study of the atrial components of 70 ablation catheter signals obtained from 20 patients was performed. Signals immediately prior to ablations wereanalyzed. The signals were divided into two groups: “good” (desired ablation answer) and “bad.” MATLAB software was used to analyze the signals. The amplitude spectrum received most attention. Afterwards, we compared similarities between “good” and “bad” signals from one patient using cross-correlation. The study population consisted of 20 patients. Each patient had one “good” signal and two or more “bad” signals. The mean frequency of the “good” signals was 13.37 ± 6.78 Hz and of the “bad” signals was 15.79 ± 6.82 Hz (p = n.s.). The relationship between “good” and “bad” signals was 0.73 ± 0.19. The amplitude spectrum of the atrial components of ablation catheter signals did not provide any useful differentiation for improving ablation accuracy

Left Ventricular Myocardial Septal Pacing in Close Proximity to LBB Does Not Prolong the Duration of the Left Ventricular Lateral Wall Depolarization Compared to LBB Pacing

Background: Three different ventricular capture types are observed during left bundle branch pacing (LBBp). They are selective LBB pacing (sLBBp), non-selective LBB pacing (nsLBBp), and myocardial left septal pacing transiting from nsLBBp while decreasing the pacing output (LVSP). Study aimed to compare differences in ventricular depolarization between these captures using ultra-high-frequency electrocardiography (UHF-ECG). Methods: Using decremental pacing voltage output, we identified and studied nsLBBp, sLBBp, and LVSP in patients with bradycardia. Timing of ventricular activations in precordial leads was displayed using UHF-ECGs, and electrical dyssynchrony (e-DYS) was calculated as the difference between the first and last activation. The durations of local depolarizations (Vd) were determined as the width of the UHF-QRS complex at 50% of its amplitude. Results: In 57 consecutive patients, data were collected during nsLBBp (n = 57), LVSP (n = 34), and sLBBp (n = 23). Interventricular dyssynchrony (e-DYS) was significantly lower during LVSP 16 ms (21; 11), than nsLBBp 24 ms (28; 20) and sLBBp 31 ms (36; 25). LVSP had the same V1d-V8d as nsLBBp and sLBBp except for V3d, which during LVSP was shorter than sLBBp; the mean difference 9 ms (16; 1), p = 0.01. LVSP caused less interventricular dyssynchrony and the same or better local depolarization durations than nsLBBp and sLBBp irrespective of QRS morphology during spontaneous rhythm or paced QRS axis. Conclusions: In patients with bradycardia, LVSP in close proximity to LBB resulted in better interventricular synchrony than nsLBBp and sLBBp and did not significantly prolong depolarization of the left ventricular lateral wall

Crowdfunding as a form of financing coffee businesses during and after the Covid-19 pandemic

This Bachelor Thesis is focused on cafés that joined crowdfunding campaigns in the Antivirus section of the Hithit portal during the coronavirus crisis. These cafés are compared with similar ones, based on predefined criteria, that did not undergo this type of campaign. The aim of this work is to evaluate whether and to which extent these campaigns could help to solve the problem of lack of finance at this time and to find out what other effects do these campaigns provide after the pandemic. This finding is carried out by semi-structured interviews, that were made in collaboration with representatives from individual selected cafés. Based on these interviews, it was found, that the biggest benefit for our respondents was the use of these crowdfunding campaigns as a good additional source of financing. However, this source should be accompanied by other sources of income. The future side effects of these campaigns were not observed to such an extent, but it is possible to mention the strengthening of the brand or stronger relationships with regular customers of some of cafés.Tato bakalářská práce je zaměřena na kavárny, které v období koronavirové krize využily crowdfundingových kampaní v sekci Antivir na portále Hithit. Tyto kavárny jsou dále porovnávány s podobnými, na základě předem definovaných kritérií, které tyto kampaně nepodstoupily. Cílem této práce je pak zhodnotit, zda a v jaké míře mohly podnikům tyto kampaně pomoci vyřešit problém v podobě nedostatku financí v této době a zjistit, jaké mohou tyto kampaně mít jiné efekty do doby po pandemii. Toto zjištění je v práci prováděno za pomoci polo-strukturovaných rozhovorů, které byly uskutečněny se zástupci jednotlivých kaváren. Na základě analýzy těchto rozhovorů bylo pak zjištěno, že hlavním přínosem crowdfundingu pro respondenty bylo jeho využití jako doplňkového zdroje financování těchto podniků, který by však měl být doprovázen i dalšími zdroji příjmů. Vedlejších efektů těchto kampaní v době po pandemii příliš pozorováno nebylo, nicméně lze zmínit přínos crowdfundingu do budoucna v podobě posílení značky či prohloubení vztahů se současnými zákazníky

Influence of Torso Model Complexity on the Noninvasive Localization of Ectopic Ventricular Activity

Location of premature ectopic ventricular activity was assessed noninvasively in five patients using integral body surface potential maps and inverse solution in terms of a single dipole. Precision of the inverse solution was studied using three different torso models: homogeneous torso model, inhomogeneous torso model including lungs and heart ventricles and inhomogeneous torso model including lungs, heart ventricles and atria, aorta and pulmonary artery. More stable results were obtained using the homogeneous model. However, in some patients the location of the resulting dipole representing the focus of ectopic activity was shifted between solutions using the homogeneous and inhomogeneous models. Comparison of solutions with inhomogeneous torso models did not show significantly different dispersions, but localization of the focus was better when a torso model including atria and arteries was used. The obtained results suggest that presented noninvasive localization of the ectopic focus can be used to shorten the time needed for successful ablation and to increase its success rate

Left bundle branch pacing compared to left ventricular septal myocardial pacing increases interventricular dyssynchrony but accelerates left ventricular lateral wall depolarization

BACKGROUND Nonselective His-bundle pacing (nsHBp), nonselective left bundle branch pacing (nsLBBp), and left ventricular septal myocardial pacing (LVSP) are recognized as physiological pacing tech niques. OBJECTIVE The purpose of this study was to compare differences in ventricular depolarization between these techniques using ultrahigh-frequency electrocardiography (UHF-ECG). METHODS In patients with bradycardia, nsHBp, nsLBBp (confirmed concomitant left bundle branch [LBB] and myocardial capture), and LVSP (pacing in left ventricular [LV] septal position without proven LBB capture) were performed. Timings of ventricular activations in precordial leads were displayed using UHF-ECG, and electrical dyssynchrony (e-DYS) was calculated as the difference between the first and last activation. Duration of local depolarization (Vd) was determined as width of the UHF-QRS complex at 50% of its amplitude. RESULTS In 68 patients, data were collected during nsLBBp (35), LVSP (96), and nsHBp (55). nsLBBp resulted in larger e-DYS than did LVSP and nsH Bp [- 24 ms (-28;-19) vs -12 ms (-16;-9) vs 10 ms (7;14), respectively; P <.001]. nsLBBp produced similar values of Vd in leads V-5 -V-8 (36-43 ms vs 38-43 ms; P = NS in all leads) but longer Vd in leads V-1 -V-4 (47-59 ms vs 41-44 ms; P <.05) as nsH Bp. LVSP caused prolonged Vd in leads V-1 -V-8 compared to nsH Bp and longer Vd in leads V-5 -V-8 compared to nsLBBp (44-51 ms vs 36-43 ms; P <.05) regardless of R-wave peak time in lead V-5 or QRS morphology in lead V-1 present during LVSP. CONCLUSION nslbbp preserves physiological LV depolarization but increases interventricular electrical dyssynchrony. LV lateral wall depolarization during LVSP is prolonged, but interventricular synchrony is preserved