Free margin length and geometric height in aortic root dilatation and leaflet prolapse: implications for aortic valve repair surgery

Abstract OBJECTIVES Our goal was to assess the aortic leaflet free margin length (FML) and geometric height (gH) in a normal aortic valve (AV), aorta dilatation and aortic leaflet prolapse. METHODS We measured the FML and gH intraoperatively in 132 patients operated on for aortic insufficiency, aortic dilatation, endocarditis or fibroelastoma. Patients were divided into 3 groups: normal tricuspid AV (group 1, n = 12), aortic dilatation (group 2, tricuspid = 43, bicuspid = 18) and leaflet prolapse (group 3, tricuspid = 32, bicuspid = 27). The FML and gH were compared between the groups and between the leaflets within each group. RESULTS In a normal tricuspid AV, the mean FML and gH were 34.7 ± 3.1 mm and 18.8 ± 1.7 mm, respectively. In group 2 tricuspid, the FML and gH were greater than those in group 1 (FML 43.7 ± 4.4, P < 0.001; gH 21.2 ± 1.8, P = 0.003). In group 3, tricuspid, the FML of the prolapsing leaflet was greater than the FML of the non-prolapsing leaflet (48.3 ± 5.4 vs 42.2 ± 3.6; P < 0.001). In group 2, bicuspid, FML of both leaflets were similar in group 2, but augmented on the fused leaflet compared to the non-fused leaflet in group 3 (fused 55.4 ± 6.3; non-fused 46.2 ± 6.2; P < 0.001). In groups 2 and 3 bicuspid, the gH of the non-fused leaflet was systematically greater than the fused leaflet (group 2 non-fused 24.6 ± 2.5 vs fused 20.4 ± 2.1; P < 0.001) CONCLUSIONS In aortic dilatation and leaflet prolapse, FML and, to a lesser extent, gH increased significantly compared to those of normal AV function. FML and gH dimensions also depended on the valve configuration (tricuspid/bicuspid). These data provide new insight into the pathomorphology of AV disease and will serve to further develop new methods of AV repair based on intraoperative measurements of the FML.

Download Full-text

Comparative Evaluation of Aortic Valve Replacement Methods in Patients Over 70 with Aortic Stenosis

Russian Sklifosovsky Journal Emergency Medical Care ◽

10.23934/2223-9022-2018-7-3-227-233 ◽

2018 ◽

Vol 7 (3) ◽

pp. 227-233 ◽

Cited By ~ 2

Author(s):

V. V. Sokolov ◽

M. V. Parkhomenko ◽

A. I. Kovalyov ◽

V. V. Vladimirov ◽

O. L. Shiryayeva ◽

...

Keyword(s):

Surgical Treatment ◽

Aortic Valve ◽

Aortic Stenosis ◽

Hospital Mortality ◽

Heart Diseases ◽

Surgical Techniques ◽

Results Of Treatment ◽

Group 3 ◽

Group 2 ◽

Group 1

BackgroundAs life expectancy and quality of health improve, more and more people reach old age, and so does the number of heart diseases. One of the most urgent problems among elderly patients is degenerative stenosis of the aortic valve (AV). The conservative treatment of symptoms of chronic heart failure with AV stenosis improves the patient’s condition only for a while, whereas surgical treatment such as replacement of AV is recognized as the main effective method of treating a defect. Recently, alternative technologies for prosthetic AV have been developed, aimed at reducing adverse effects of artificial circulation (AC) in high-risk patients and minimizing the scope of surgical intervention.Aim of studyThe aim of the study was to evaluate the immediate results of surgical treatment of aortic stenosis using different methods in patients over 70.Material and methodsThe article presents the results of treatment of 64 patients over 70 with isolated AV stenosis, operated with different surgical techniques from July, 2016 to January, 2018. All patients were divided into three groups, differing in the severity of the initial condition and the method treatment. Group 1 (transcatheter implantation of the prosthetic AV, EuroSCORE II — 21.81%) consisted of 19 patients, Group 2 (non-suture implantation of a Perceval prosthetic valce under the AC, EuroSCORE II — 13.81%) consisted of 13 patients and Group 3 (“standard” prosthetics, EuroSCORE II — 9.89%) consisted of 32 patients.ResultsIn Group 1, two patients died, the hospital mortality was 10.5%. In Group 2 and Group 3, one patient died, the hospital mortality was 7.6 and 3.1%, respectively. Implantation of a permanent pacemaker was required in three patients (15.7%) from the TAVI group after installation of Medtronic Core Valve and two patients (15.3%) from the Perceval group.ConclusionThe obtained results of AV replacement by various methods allowed to expand indications for the management of AV stenosis in patients of the older age group with a high surgical risk of operation under AC conditions who had not previously been considered candidates for surgical treatment of aortic malformation due to the age and severity of the concomitant pathology.

Download Full-text

Expression of osteoprotegerin and soluble ligand of receptor of kappa-B transcription factor activator in the calcification of aortic valve

Biomeditsinskaya Khimiya ◽

10.18097/pbmc20196501057 ◽

2019 ◽

Vol 65 (1) ◽

pp. 57-62

Author(s):

I.V. Voronkina ◽

O.B. Irtyuga ◽

L.V. Smagina ◽

P.E. Adamova ◽

E.V. Zhiduleva ◽

...

Keyword(s):

Aortic Valve ◽

Aortic Stenosis ◽

Severe Aortic Stenosis ◽

Aortic Dilatation ◽

Valve Calcification ◽

Soluble Ligand ◽

Rank System ◽

Group 3 ◽

Group 2

The mechanism of valve calcification that is the main cause of aortic stenosis formation and progression is not yet clear. In recent years, the role of the OPG/RANKL/RANK system is considered as one of possible variants of pathogenesis of valve calcification. In presented work the differences in OPG and sRANKL levels involved in the calcification processes in tissues of patients with severe aortic stenosis have been examined. The study was performed using three groups of patients: group 1 – patients with aortic stenosis, group 2 – patients with aortic aneurysm, and group 3 – patients with aortic stenosis and aortic dilatation. In patients with aortic stenosis, the level of RANKL was significantly higher, and the level of RANKL was higher in valve than in tissue. The negative correlation between aortic dilatation and RANKL level indicated the lack of RANKL influence on pathogenesis of aortic dilatation. The obtained data confirm the increased expression of RANKL in patients with aortic valve calcification. The results of this study confirm importance of the OPG/RANKL/RANK system in calcification in patients with aortic stenosis. Athough patients of all groups had comparable values of OPG (including patients with aortic dilatation), the RANKL level increased only in patients with aortic stenosis. This suggest involvement of some additional mechanisms influencing the increase of RANKL expression.

Download Full-text

Aortic root surgery: Early postoperative results of different surgical techniques

Medicina ◽

10.3390/medicina45030026 ◽

2009 ◽

Vol 45 (3) ◽

pp. 197 ◽

Cited By ~ 1

Author(s):

Rimantas Benetis ◽

Eglė Ereminienė ◽

Povilas Jakuška ◽

Dainius Karčiauskas ◽

Šarūnas Kinduris ◽

...

Keyword(s):

Aortic Valve ◽

Aortic Root ◽

Surgical Techniques ◽

Ascending Aorta ◽

Aortic Root Replacement ◽

Postoperative Results ◽

Aortic Root Surgery ◽

Group 3 ◽

Group 2 ◽

Group 1

The aim of the study was to evaluate early postoperative results of different surgical techniques of aortic root surgery. Material and methods. Between January 2004 and November 2007, a cohort of 83 patients underwent aortic root surgery in the Heart Center, Hospital of Kaunas University of Medicine. Patients were divided into three groups: Group 1 (18 patients) – reimplantation of the aortic valve within a vascular graft (David operation), Group 2 (48 patients) – replacement of the ascending aorta and aortic valve using a valved conduit (Bentall de Bono operation), and Group 3 (17 patients) – biological aortic root replacement. Study protocol included clinical data, operative data, and postoperative major adverse effects: reoperations for bleeding, stroke and lethal outcomes. Results. Patients undergoing biological aortic root replacement were older as compared with other groups. The mean age in the Group 1 was 50.3±3.5 years vs. 57±2.0 years in the Group 2 and 67.8±3.3 years in the Group 3 (P<0.05). The main indication for the aortic root surgery was the aneurysm of the aortic root and ascending aorta in the Group 1 and 2 patients (64.7% and 72%), while in the Group 3, the main indication was fibrocalcinosis of aortic valve, aortic annulus, and ascending aorta (61.1%). The 30-day hospital mortality rates were as follows: 5.8% (n=1), in the Group 1; 10.4% (n=5), in the Group 2; 5.5% (n=1), in the Group 3. In the early postoperative period, 11 reoperations were performed due to bleeding events: in the Group 1, after planned/emergency surgery (n=2/2), and in the Group 2 (n=1/6), respectively. The function of aortic valve improved significantly in all groups of patients early after surgery. In the Group 1, the degree of aortic regurgitation decreased from 2.5±0.8 to 1.1±0.6 (P<0.05); in the Groups 2 and 3, the mean gradient through the aortic valve decreased from 39.9±7.5 to 17.1±5.3 mm Hg and from 48.8±18.0 to 20.1±11.0 mm Hg, respectively (P<0.05). No reoperation for aortic valve failure before the discharge was required in all groups of patients, and neither thromboembolic complications nor stroke events were noted in any group. Conclusions. Different aortic root surgery techniques showed similar postoperative results. New aortic root surgery methods such as aortic root-preserving/sparing procedures and concurrent aortic valve leaflet repair or aortic root replacement with the bioprosthesis can be selected for a diverse class of aortic root pathology with low perioperative mortality rates and good early postoperative results.

Download Full-text

Low-gradient aortic stenosis in patients with concomitant mitral regurgitation - a subgroup analysis from the German aortic valve registry (GARY)

European Heart Journal - Cardiovascular Imaging ◽

10.1093/ehjci/jeaa356.363 ◽

2021 ◽

Vol 22 (Supplement_1) ◽

Author(s):

B Alushi ◽

S Ensminger ◽

U Balaban ◽

C Frerker ◽

V Falk ◽

...

Keyword(s):

Aortic Valve ◽

Mitral Regurgitation ◽

Aortic Stenosis ◽

Aortic Valve Area ◽

Group 3 ◽

Group 2 ◽

The Impact ◽

Grade Iii ◽

Valve Area ◽

Group 1

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This work was supported by German Cardiac Society, German Society for Thoracic and Cardiovascular Surgery, and German Heart Foundation. Statistical funding support by the German Center for Cardiovascular Research/Deutsches Zentrum für Herz-Kreislauf Forschung (DZHK). Background Patients with severe aortic stenosis (AS) frequently present concomitant mitral regurgitation (MR), which may interfere with echocardiographic measurement of mean pressure gradient (MPG), maximal flow velocity and aortic valve area (AVA). Purpose We therefore, aimed to investigate the impact of different grades of MR on parameters of AS severity in a large cohort of all-comer patients with severe AS, prospectively included in the national German Aortic Registry (GARY). Methods All patients undergoing transcatheter or surgical aortic valve replacement for severe AS enrolled in GARY between 2011 and 2017 were considered for this analysis. After excluding cases with mitral stenosis and unknown causes of MR, 119,641 patients were considered for the present study. Based on LVEF, the study population was divided into the following subgroups: group 1 (LVEF < 30%, n = 7545), group 2 (LVEF 30-50%, n = 30,116), and group 3 (LVEF > 50%, n = 81,980). Differences in the values of the mPG were explored in each group and in relation to the decremental values of aortic valve area (AVA). Results Overall, 37,489 (31.3%) patients had no MR, 77,890 (65.1%) had MR grade I-II, and 4262 (3.6%) had MR grade III-IV. In group 1, 2 and 3, no MR was reported in 1339 (17.7%), 7612 (25.3%) and 28,538 (34.8%) patients respectively. MR grade I-II was more frequently observed (group 1 5621 [74.5%] vs. group 2 20,972 [69.6%] vs. group 3 51,297 [62.6%]), whereas MR grade III-IV was observed less frequently and present only in 585 (7.7%), 1532 (5.1%) and 2145 (2.6%) patients in subgroups 1, 2 and 3, respectively. The aortic mPG was significantly lower in subgroup 1 compared to 2 and 3 (33.74 ± 14.93 versus 41.4 ± 16.47 and 46 ± 16.19mmHg respectively, p < 0.001). With increasing severity of MR, there was a significant reduction of the aortic mPG in each LVEF subgroup (Figure 1). This pattern was maintained irrespective of the AVA value. Conclusions In patients with severe AS, concomitant MR may potentially affect diagnostic accuracy of echocardiographic AS evaluation. In this first GARY analysis of patients with severe AS and concomitant MR, we observed that increasing MR severity affects transvalvular aortic mPG and results in a low-gradient AS pattern. In contrast, AVA is a robust diagnostic parameter for the diagnosis of true severe AS that maintains its validity independently of LVEF and severity of concomitant MR. Abstract Figure 1

Download Full-text

In-vivo evaluation of the effect of cyanoacrylate on prosthetic vascular graft infection – does cyanoacrylate increase the severity of infection?

VASA ◽

10.1024/0301-1526/a000867 ◽

2020 ◽

Vol 49 (4) ◽

pp. 281-284

Author(s):

Atıf Yolgosteren ◽

Gencehan Kumtepe ◽

Melda Payaslioglu ◽

Cuneyt Ozakin

Keyword(s):

Vascular Graft ◽

Graft Infection ◽

Vascular Graft Infection ◽

Group 4 ◽

Significant Difference ◽

Group 3 ◽

Group 2 ◽

Prosthetic Vascular Graft Infection ◽

Group 1

Summary. Background: Prosthetic vascular graft infection (PVGI) is a complication with high mortality. Cyanoacrylate (CA) is an adhesive which has been used in a number of surgical procedures. In this in-vivo study, we aimed to evaluate the relationship between PVGI and CA. Materials and methods: Thirty-two rats were equally divided into four groups. Pouch was formed on back of rats until deep fascia. In group 1, vascular graft with polyethyleneterephthalate (PET) was placed into pouch. In group 2, MRSA strain with a density of 1 ml 0.5 MacFarland was injected into pouch. In group 3, 1 cm 2 vascular graft with PET piece was placed into pouch and MRSA strain with a density of 1 ml 0.5 MacFarland was injected. In group 4, 1 cm 2 vascular graft with PET piece impregnated with N-butyl cyanoacrylate-based adhesive was placed and MRSA strain with a density of 1 ml 0.5 MacFarland was injected. All rats were scarified in 96th hour, culture samples were taken where intervention was performed and were evaluated microbiologically. Bacteria reproducing in each group were numerically evaluated based on colony-forming unit (CFU/ml) and compared by taking their average. Results: MRSA reproduction of 0 CFU/ml in group 1, of 1410 CFU/ml in group 2, of 180 200 CFU/ml in group 3 and of 625 300 CFU/ml in group 4 was present. A statistically significant difference was present between group 1 and group 4 (p < 0.01), between group 2 and group 4 (p < 0.01), between group 3 and group 4 (p < 0.05). In terms of reproduction, no statistically significant difference was found in group 1, group 2, group 3 in themselves. Conclusions: We observed that the rate of infection increased in the cyanoacyrylate group where cyanoacrylate was used. We think that surgeon should be more careful in using CA in vascular surgery.

Download Full-text

Abnormal Haemostasis and Blood Viscosity in Malignant Hypertension

Thrombosis and Haemostasis ◽

10.1055/s-0038-1661190 ◽

1984 ◽

Vol 52 (03) ◽

pp. 253-255 ◽

Cited By ~ 11

Author(s):

C Isles ◽

G D O Lowe ◽

B M Rankin ◽

C D Forbes ◽

N Lucie ◽

...

Keyword(s):

Blood Pressure ◽

Blood Viscosity ◽

Renal Damage ◽

Antithrombin Iii ◽

Plasma Viscosity ◽

Malignant Hypertension ◽

Fibrin Deposition ◽

Group 3 ◽

Group 2 ◽

Group 1

SummaryWe have previously shown abnormalities of haemostasis suggestive of intravascular coagulation in patients with malignant hypertension, a condition associated with retinopathy and renal fibrin deposition. To determine whether such abnormalities are specific to malignant hypertension, we have measured several haemostatic and haemorheological variables in 18 patients with malignant hypertension (Group 1), 18 matched healthy controls (Group 2), and 18 patients with non-malignant hypertension (Group 3) matched for renal pathology, blood pressure and serum creatinine with Group 1. Both Groups 1 and 3 had increased mean levels of fibrinogen, factor VIIIc, beta-thrombo- globulin, plasma viscosity and blood viscosity (corrected for haematocrit); and decreased mean levels of haematocrit, antithrombin III and platelet count. Mean levels of fast antiplasmin and alpha2-macroglobulin were elevated in Group 1 but not in Group 3. We conclude that most blood abnormalities are not specific to malignant hypertension; are also present in patients with non-malignant hypertension who have similar levels of blood pressure and renal damage; and might result from renal damage as well as promoting further renal damage by enhancing fibrin deposition. However increased levels of fibrinolytic inhibitors in malignant hypertension merit further investigation in relation to removal of renal fibrin.

Download Full-text

Features of postoperative period in patients with chronic venous insufficiency: phlebectomy versus thermal ablation

Hirurg (Surgeon) ◽

10.33920/med-15-2001-05 ◽

2020 ◽

pp. 64-75

Author(s):

E. Burleva ◽

O. Smirnov ◽

S. Tyurin

Keyword(s):

Postoperative Period ◽

Chronic Venous Insufficiency ◽

Thermal Ablation ◽

Venous Insufficiency ◽

Clinical Symptoms ◽

Varicose Veins ◽

Statistical Processing ◽

Group 3 ◽

Group 2 ◽

Group 1

The purpose of the study was to conduct a comparative assessment of the course of the postoperative period after phlebectomy and thermal ablation in patients with varicose veins of the lower extremities in the system of the great saphenous vein (GSV) with class C2 of chronic venous insufficiency (CVI) — CEAP class C2. Materials and methods: 455 patients (455 limbs) with CEAP class C2. Group 1 (n = 154) received stripping + minimally invasive phlebectomy; Group 2 — endovenous laser ablation (EVLA) of GSV trunk + sclerotherapy of varicose veins; 3 group (n = 150) — radiofrequency ablation (RFA) of the GSV + sclerotherapy. All patients were united by a single tactical solution — the elimination of pathological vertical reflux in GSV. In each group, patients were with similar hemodynamic profile were selected (Group 1 = 63; Group 2 = 61; Group 3 = 61). The course of the postoperative period (from 2 days to 2 months) was compared for pain (visual analog scale — VAS), clinical symptoms of chronic venous insufficiency, degree of satisfaction (Darvall questionnaire), and duration of disability. Statistical processing was carried out using Excel programs for Windows XP, MedCalc® (version 11.4.2.0., Mariakerke, Belgium). Results: Postoperative pain is more pronounced (during day 1 for Group 1–4.0, Group 2–3.0, Group 3–2.0) and more prolonged (up to 4 days) after open surgeries (p < 0.05). The dynamics of the clinical symptoms of CVI (including varicose syndrome and use of compression therapy) could not be fully evaluated in connection with the ongoing sclerotherapy procedures for patients of Groups 2 and 3. Satisfaction of patients with aesthetic aspects was higher than expected in all groups. Reliable statistical differences proved decrease in days of disability (Group 1–14; Group 2–4; Group 3–3) and earlier return to physical activities and work in patients after thermal ablation in comparison with phlebectomy. Conclusion: The study shows that all three methods for eliminating vertical reflux in the GSV can be proposed for a large category of patients with CEAP of class C3 and C2. Medical and social rehabilitation of patients using endovascular thermal ablation technologies proceeds faster, which is beneficial both for the patients and for society.

Download Full-text

Analysis of the quality of early diagnostics of cardiovascular diseases in students of educational institutions of Khabarovsk (according to the data of preventive examinations)

Dalʹnevostočnyj medicinskij žurnal ◽

10.35177/1994-5191-2020-4-13-16 ◽

2020 ◽

pp. 13-16

Keyword(s):

Blood Pressure ◽

Cardiovascular Diseases ◽

Sinus Tachycardia ◽

Blood Pressure Level ◽

Educational Institutions ◽

Conduction Disturbances ◽

Group 3 ◽

Group 2 ◽

Group 1

To identify the prevalence of early pathology of cardiovascular diseases, a survey of 400 200 girls) in the age group 15 and 17 years old was conducted as a part of routine medical of the level of blood pressure (BP) was carried out, with the calculation of the average level pressure on the basis of three separate measurements estimated by percentile tables for a registration of a standard resting ECG in 12 leads. According to the results of the survey, into 3 groups: with an increase in blood pressure above 95 ‰ (group 1 – 16 people), which recorded in males (p<0,05); Group 2 (67 people) – adolescents with a normal blood pressure level and group 3 of adolescents with a decrease in blood pressure below 5 ‰ changes in the form of rhythm and conduction disturbances were noted in almost every a predominance of sinus tachycardia in the first group. In the third group of adolescents, form of ectopic rhythm and pacemaker migration were significantly more frequently only 78 % of adolescents were referred for consultation and in-depth examination by a pediatric cardiologist.

Download Full-text

Does Perioperative Hemoglobin A1c Level Affect the Incidence, Pattern and Mortality of Lower Extremity Amputation?

Current Vascular Pharmacology ◽

10.2174/1570161116666180123112529 ◽

2019 ◽

Vol 17 (4) ◽

pp. 354-364

Author(s):

Hassan Al-Thani ◽

Moamena El-Matbouly ◽

Maryam Al-Sulaiti ◽

Noora Al-Thani ◽

Mohammad Asim ◽

...

Keyword(s):

Glycemic Control ◽

Lower Extremity ◽

Hazard Ratio ◽

Lower Extremity Amputation ◽

Group 4 ◽

Group 3 ◽

Group 5 ◽

Group 2 ◽

Extremity Amputation ◽

Group 1

Background: We hypothesized that perioperative HbA1c influenced the pattern and outcomes of Lower Extremity Amputation (LEA). Methods: A retrospective analysis was conducted for all patients who underwent LEA between 2000 and 2013. Patients were categorized into 5 groups according to their perioperative HbA1c values [Group 1 (<6.5%), Group 2 (6.5-7.4%), Group 3 (7.5-8.4%), Group 4 (8.5-9.4%) and Group 5 (≥9.5%)]. We identified 848 patients with LEA; perioperative HbA1c levels were available in 547 cases (Group 1: 18.8%, Group 2: 17.7%, Group 3: 15.0%, Group 4: 13.5% and Group 5: 34.9%). Major amputation was performed in 35%, 32%, 22%, 10.8% and 13.6%, respectively. Results: The overall mortality was 36.5%; of that one quarter occurred during the index hospitalization. Mortality was higher in Group 1 (57.4%) compared with Groups 2-5 (46.9%, 38.3%, 36.1% and 31.2%, respectively, p=0.001). Cox regression analysis showed that poor glycemic control (Group 4 and 5) had lower risk of mortality post-LEA [hazard ratio 0.57 (95% CI 0.35-0.93) and hazard ratio 0.46 (95% CI 0.31-0.69)]; this mortality risk persisted even after adjustment for age and sex but was statistically insignificant. The rate of LEA was greater among poor glycemic control patients; however, the mortality was higher among patients with tight control. Conclusion: The effects of HbA1c on the immediate and long-term LEA outcomes and its therapeutic implications need further investigation.

Download Full-text

Cholinesterase Activities and Oxidative Stress in Cattle Experimentally Exposed to Nitrate/Nitrite in Cultivated Pasture with Different Fertilization Schemes

Acta Scientiae Veterinariae ◽

10.22456/1679-9216.82068 ◽

2018 ◽

Vol 46 (1) ◽

Author(s):

Ricardo Christ ◽

Aleksandro Schafer Da Silva ◽

Mateus Eloir Grabriel ◽

Luan Cleber Henker ◽

Renan Augusto Cechin ◽

...

Keyword(s):

Oxidative Stress ◽

Enzyme Activity ◽

Cholinesterase Activity ◽

Blood Samples ◽

Group 3 ◽

Cholinesterase Activities ◽

Group 2 ◽

Nitrate And Nitrite ◽

And Oxidative Stress ◽

Group 1

Background: Nitrate and nitrite poisoning is associated with pasture intake that has high nitrate levels and leads to acute methemoglobinemia. Pasture may accumulate nitrate under certain conditions, such as excessively fertilized soil or environmental conditions that enhance the N absorption (rain preceded by a period of drought). After ingestion of plants, this substrate reaches the rumen and, in physiological conditions, is reduced to nitrite and afterward to ammonia. The aim of this study was to evaluate changes in cholinesterase activities and oxidative stress caused by subclinical poisoning for nitrate and nitrite in cattle fed with Pennisetum glaucum in three different fertilization schemes. Materials, Methods & Results: In order to perform the experimental poisoning, the pasture was cultivated in three different paddocks: with nitrogen topdressing (urea; group 1), organic fertilizer (group 2) or without fertilizer (group 3; control). Nitrate accumulation in forage was evaluated by the diphenylamine test. After food fasting of 12 h, nine bovine were randomly allocated to one of the experimental groups and fed with fresh forage (ad libitum) from respective paddock. In different time points from beginning of pasture intake (0, 2, 4, 6 and 9 h) heart rate and respiratory frequency were assessed, as well as mucous membrane color and behavioral changes. Blood samples from jugular vein into vials with and without anticoagulant were collected. From blood samples, serum nitrite levels, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzyme activity were evaluated, as well as oxidative stress through the following parameters: levels of nitrate/nitrite (NOx), thiobarbituric acid reactive substances (TBARS) and reactive oxygen species (ROS), beyond the antioxidant system by enzyme activity measurement of catalase (CAT) and superoxide dismutase (SOD). The diphenylamine test was positive to group 1 and 2, so that the pasture presented 3.16 mg/kg, 2.98 mg/kg and 1.67 mg/kg of nitrate for group 1, 2 and 3, respectively. In addition, cows from group 1 demonstrated increased (P < 0.05) nitrite levels in serum, compared to other groups, and greater heart rate after 9 h (P < 0.05). The AChE and BChE activity in group 1 showed significant increase (P < 0.05) at 4 and 6 h (AChE), and 4 and 9 h (BChE) compared to group 3. Also, NOx levels were lower at 6 and 9 h (P < 0.05) and at 9 h (P < 0.05) for animals of group 1 and 2, respectively, when compared to group 3. Furthermore, in the group 1 levels of ROS and TBARS were significantly higher (P < 0.05) after 2 and 4 h, and 6 and 9 h compared to other groups, respectively. The CAT activity increased significantly (P < 0.05) with 2 and 4 h of the experiment, but on the other hand, decreased at 6 and 9 h in group 1. Nevertheless, the animals from group 2 presented only a significant reduction in this enzyme activity at 9 h. Furthermore, SOD activity was reduced in animals of groups 1 (P < 0.05) at 4, 6 and 9 h, compared to other groups. Discussion: It was concluded that the nitrate and nitrite poisoning by pasture intake cultivated and fertilized with urea leads to increased levels of serum nitrite, as well as the cholinesterase activity and causes oxidative stress in cattle. It is conjectured that the cholinesterase activity and oxidative stress may assist in understanding the pathophysiology of changes caused by poisoning.Keywords: plant toxicology, poisoning, methemoglobin, cholinergic system, oxidative stress.

Download Full-text