An approach to 24-hour electrocardiogram monitoring in sheep experimental model

Sheep could be an excellent research subject for large animal experimental studies because of their heart structure and physiology have a lot similarity to the human. Long term ECG monitoring is a convenient tool for human and possibly veterinary clinical practice and research. Continuous ECG recording can be used to monitor and evaluate body physiological responses in various experimental conditions. Experience on sheep ECG monitoring techniques is sparse and mostly focused on short term ECG recordings. We developed a peculiar technique of 24-hour sheep ECG monitoring based on the available data on large mammal model, where we tried to share some insights and practical solutions working with this type of animals for ECG monitoring by using several commercially available ECG monitors also used for the human practice. Some producer specific hardware and software characteristic that we found important in daily practice were also discussed. In conclusion, sheep as big animal is relatively good object for Holter monitoring experimental studies: ECG monitoring is easily affordable, registered ECG signal is of similar quality as in human clinical practice, which is sufficient for the heart rhythm monitoring and arrhythmia and conduction disorder diagnostics. Additional effort might be needed for 24-hour heart rate variability calculations because manual revision of software ECG signal interpretations is requiring, but short-term calculations can be made easy

Influence of long-term fertilization on changes mineral nutrients in the sandy loam combisols

Tyrimų tikslas nustatyti daugiamečio (38 metų) tręšimo įvairiomis azoto, fosforo ir kalio trąšų normomis poveikį pagrindinių maisto medžiagų pokyčiams smėlingame lengvo priemolio sekliau karbonatingame giliau glėjiškame rudžemyje. Vidutiniais 2008-2009 metų tyrimų duomenimis patręšųs žemės ūkio augalus 90 kg ha-1 azoto norma mineralinio azoto kiekis 0-60 cm dirvožemio sluoksnyje padidėjo 1,52-7,22mg kg-1, arba 30-138%. Mažiau mineralinio azoto susikaupia dirvožemyje kai azoto trąšos naudojamos derinyje su fosforo ir kalio trąšomis. Judriojo fosforo kiekis dirvožemyje priklausė nuo fosforo trąšų normų ir jų santykio azoto ir kalio normomis. Jeigu fosforo trąšomis netręštuose laukeliuose judriojo fosforo rasta tik 72-80 mg kg-1, tai ilgą laiką tręšiant vidutinėmis (90 kg ha-1) fosforo trąšų normomis judriojo fosforo nustatyta net iki 235- 276 mg kg-1. Fosforo kiekiui dirvožemyje įtakos taip pat turėjo žemės ūkio augalų tręšimas azoto bei kalio trąšomis, kurios didindamos žemės ūkio augalų derlių ir jame sukauptą fosforo kiekį, mažino šio elemento susikaupimą dirvožemyje. Žemės ūkio augalus patręšus 90 kg ha-1 azoto norma (P180K180 trąšų fone) judriojo fosforo dirvožemyje sumažėjo nuo 447 ir 412 mg kg-1, o patręšus tokia pat kalio trąšų norma (N90P180 fone) – nuo 488 iki 450 mg kg-1. Judriojo kalio kiekis dirvožemyje labiausiai priklausė nuo kalio trąšų normų, tačiau nemažos įtakos turėjo ir tręšimas azoto ir kalio trąšomis. Dėl kalio trąšų sąveikos su azoto ir fosforo trąšomis, judriojo kalio kiekis dirvožemyje turėjo tendenciją mažėti. Kalio trąšomis netręštuose laukeliuose judriojo kalio dirvožemyje rasta tik 80-92 mg kg-1. Dėl tręšimo kalio trąšomis, jo kiekis dirvožemyje, nors ir mažiau negu judriojo fosforo, tačiau didėjo. N90P90 trąšų fone, augalus patręšus 90 ir 180 kg ha-1 kalio trąšų normomis, judriojo kalio dirvožemyje nustatyta atitinkamai 122 ir 166 mg kg-1. Kalio kiekiui dirvožemyje įtakos taip pat turėjo augalų tręšimas ne tik kalio, bet ir azoto bei fosforo trąšomis. Azoto ir fosforo trąšų įtakoje pastebima judriojo kalio kiekio mažėjimo tendencija dirvožemyje. Judriosios sieros kiekio pokyčiai dirvožemyje priklausė nuo augalų tręšimo fosforo trąšomis (granuliuotu superfosfatu). Nuo azoto (amonio salietra) ir kalio trąšų (kalio chloridas) judriosios sieros kiekiai dirvožemyje mažai kito.Research by the multi-purpose (38years) in different fertilizer nitrogen, phosphorus and potassium fertilizer rates as the main effects of nutrient changes in the sandy loam calcareous Cambisol Endohypogleyic. Averaged data for 2008-2009 for research in agricultural crops fertilized 90 kg ha-1 rate of mineral nitrogen in 0-60 cm soil layer increased from 1.52 to 7.22 mg kg-1, or 30-138%. Less accumulation of mineral nitrogen in soils where nitrogen fertilizers are used in combination with phosphorus and potassium fertilizers. Phosphorus content in the soil depended on the phosphorus fertilizer rates and their ratio of nitrogen and potassium rates. If phosphorus fertilizer unfertilized plots phosphorus found in only 72-80 mg kg-1, the average long-term fertilization (90 kg ha-1) phosphorus fertilizer rates set up to 235-276 mg kg-1. Phosphorus content in soil have also been affected crop fertilizer nitrogen and potassium fertilizers are increasing crop yields and the cumulative amount of phosphorus, reducing the accumulation of this element in soil. Agricultural crops fertilized 90 kg ha-1 rate of nitrogen (fertilizer P180K180 background) phosphorus in the soil decreased from 447 and 412 mg kg-1, and the same fertilization rate of potassium fertilizer (N90P180 background) - from 488 to 450 mg kg-1. Available potassium content in soil was mainly due to potassium fertilizer rates, but had a significant impact on fertilization and nitrogen and potassium fertilizers. The interaction of potassium fertilizers with nitrogen and phosphorus fertilizers, potassium content in the soil tended to decrease. Potassium fertilizer unfertilized fields available potassium in soils found in only 80-92 mg kg-1. The fertilizer potassium, the quantity of soil, though less than phosphorus, but increased. N90P90 fertilizer in the background, plants fertilized 90 and 180 kg ha-1 potassium fertilizer rates, the potassium found in soil, respectively 122 and 166 mg kg-1. Potassium content in soil have also been affected plant fertilization not only potassium but also nitrogen and phosphorus fertilizers. Nitrogen and phosphorus fertilizers on the potassium content is observed downward trend in the soil. Mobile sulfur in the soil belonged to the changes from plant fertilizer phosphorus fertilizer (granular superphosphate). Nitrogen (ammonium nitrate) and potassium fertilizers (potassium chloride) of mobile sulfur content in the soil little else.Žemės ūkio akademijaVytauto Didžiojo universiteta

Ilgalaikio tręšimo poveikis maisto medžiagų pokyčiams smėlingo priemolio rudžemyje

Vytauto Didžiojo universitetasŽemės ūkio akademij

Prognostication of poor survival after cardiac resynchronization therapy

Background and Objectives: Cardiac resynchronization therapy (CRT) is a successful treatment option for appropriately selected patients. However, one–third of recipients do not experience any positive outcome or their condition even declines. We aimed to assess preimplantation factors associated with worse survival after the CRT. Materials and Methods: This was a retrospective unicenter trial. The study cohort included 183 consecutive CRT-treated patients. Baseline demographic, clinical, electrocardiographic, and echocardiographic characteristics were analyzed. Results: After the median follow-up of 15.6 months (9.3–26.3), 20 patients had died (11%). In multivariate Cox regression analysis, ischemic origin of heart failure (HF) was a significant predictor of poor survival (adjusted hazard ratio (aHR) 15.235, 95% confidence interval (CI) (1.999–116.1), p = 0.009). In univariate Cox regression, tricuspid annular plane systolic excursion (TAPSE) <15.5 mm (sensitivity 0.824, specificity 0.526; HR 5.019, 95% CI (1.436–17.539), p = 0.012), post-implantation prescribed antiplatelet agents (HR 2.569, 95% CI (1.060–6.226), p = 0.037), statins (HR 2.983, 95% CI (1.146–7.764), p = 0.025), and nitrates (HR 3.694, 95% CI (1.342–10.171), p = 0.011) appeared to be related with adverse outcome. Conclusions: ischemic etiology of HF is a significant factor associated with worse survival after the CRT. Decreased TAPSE is also related to poor survival

Evaluation of left ventricular longitudinal function and synchrony after dual chamber pacemaker implantation

Background and objective: To evaluate left ventricular (LV) longitudinal function and dyssynchrony mechanisms after dual chamber pacemaker implantation. Materials and methods: The speckle tracking imaging technique was used for quantification of global longitudinal function of the left ventricle and for dyssynchrony evaluation before pacemaker implantation and after 3-month follow-up. The study group consisted of 98 patients with conventional indications for dual chamber pacemaker implantation. Results: Speckle tracking echocardiographic methods and image postprocessing revealed impairment of global longitudinal strain and significant LV dyssynchrony derived from 12 basal and mid-septum segments usually untraceable with conventional echocardiographic methods. Despite good physical performance and ejection fraction, global longitudinal strain significantly decreased in all patients from −15.08 ± 0.46 to −13.56 ± 0.5 (P &lt; 0.05) as well as mitral annulus movement decreased from 11.57 ± 2.41 to 8.46 ± 1.74 cm/s (P &lt; 0.001) and from 12.55 ± 2.75 to 10.78 ± 2.82 mm (P &lt; 0.001). It was expected that patients with dual chamber pacemaker will develop inter- and intraventricular dyssynchrony, but our study showed that pacing lead position did not prevent from LV dysynchronisation and only changed the mechanism. Conclusions: Global longitudinal strain and LV dyssynchrony assessment enables us to detect early signs of LV dysfunction. Mechanisms of dyssynchrony development will be useful for pacemaker programing choices in order to prevent further dyssynchronisation

Idiopathic ventricular tachycardia in children: curative therapy with radiofrequency ablation

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 (CartoTM) 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

Structural and electrical investigation of (Ag3AsS3)x(As2S3)1−x superionic glasses

Structural studies of (Ag3AsS3)x (As2S3)1−x chalcogenide superionic glasses in the compositional range x = 0:3 −0:9 were performed by scanning electron microscopy. Temperature and compositional dependences of transmission coefficient, electrical conductivity, and activation energy were investigated

The Predictive Value of Tissue Doppler Indices for Early Recurrence of Atrial Fibrillation After Electrical Cardioversion

Purpose: Spectral tissue Doppler-derived E/e' ratio has been proposed as the best parameter for prediction of atrial fibrillation (AF). Relaxation and contraction are equivalent parts of a continuous cardiac cycle, where systolic and diastolic abnormalities have a variable contribution to the left ventricle (LV) failure. The aim of this study was to investigate whether the E/(e'xs') ratio is a better index than E/e' to predict AF recurrence and to determine the changes of spectral tissue Doppler indices 1 month after the electrical cardioversion (ECV). Patients and methods: The study included 77 persistent AF patients with restored sinus rhythm (SR) after ECV. Only patients with normal LV ejection fraction (EF) were included. Echocardiography and NT-proBNP laboratory findings were performed. A primary outcome was the early (within 1 month) recurrence of AF. Results: After a 1 month follow-up period, 39 patients (50.6%) were in SR. E/e' (HR=1.74, P=0.001) and E/(e'×s') ratios (HR=8.17, P=0.01) were significant predictors of AF recurrence. E/(e'×s') in combination with LV end-diastolic diameter >49.3 mm and NT-proBNP >2000 ng/L demonstrated a higher contribution in the model to predict AF recurrence compared to the E/e' ratio (18.94, P=0.005 vs 1.95, P=0.001). On ROC analysis, E/(e'×s') and E/e' showed similar diagnostic accuracy (E/(e'×s'), AUC=0.71, P=0.002 and E/e', AUC=0.75, P<0.0001). Average e' value significantly decreased after 1 month in SR (from 10.76±1.24 to 8.96±1.47 cm/s, P=0.01), E wave did not change significantly and E/e' ratio tended to improve. A decrease of average e' and an increase of average s' values led to significant improvement of E/(e'xs') ratio. Conclusion: E/(e'xs') and E/e' ratios are comparable to predict early AF recurrence after ECV in patients with persistent AF. The e' value decreased significantly after 1 month follow-up period after ECV for persistent AF patients