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1.
J Vet Cardiol ; 52: 1-13, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38290222

RESUMO

INTRODUCTION/OBJECTIVES: Spontaneous pulmonary vein (PV) activity triggers atrial fibrillation (AF) in humans. Although AF frequently occurs in horses, the origin remains unknown. This study investigated the structural and electro-anatomical properties of equine PVs to determine the potential presence of an arrhythmogenic substrate. ANIMALS, MATERIALS AND METHODS: Endocardial three-dimensional electro-anatomical mapping (EnSite Precision) using high-density (HD) catheters was performed in 13 sedated horses in sinus rhythm. Left atrium (LA) access was obtained retrogradely through the carotid artery. Post-mortem, tissue was harvested from the LA, right atrium (RA), and PVs for histological characterization and quantification of ion channel expression using immunohistochemical analysis. RESULTS: Geometry, activation maps, and voltage maps of the PVs were created and a median of four ostia were identified. Areas of reduced conduction were found at the veno-atrial junction. The mean myocardial sleeve length varied from 28 ± 13 to 49 ± 22 mm. The PV voltage was 1.2 ± 1.4 mV and lower than the LA (3.4 ± 0.9 mV, P < 0.001). The fibrosis percentage was higher in PV myocardium (26.1 ± 6.6%) than LA (14.5 ± 5.0%, P = 0.003). L-type calcium channel (CaV1.2) expression was higher in PVs than LA (P = 0.001). T-type calcium channels (CaV3.3), connexin-43, ryanodine receptor-2, and small conductance calcium-activated potassium channel-3 was expressed in PVs. CONCLUSIONS: The veno-atrial junction had lower voltages, increased structural heterogeneity and areas of slower conduction. Myocardial sleeves had variable lengths, and a different ion channel expression compared to the atria. Heterogeneous properties of the PVs interacting with the adjacent LA likely provide the milieu for re-entry and AF initiation.


Assuntos
Fibrilação Atrial , Veias Pulmonares , Animais , Cavalos , Veias Pulmonares/patologia , Fibrilação Atrial/veterinária , Fibrilação Atrial/patologia , Feminino , Masculino , Doenças dos Cavalos/patologia , Átrios do Coração/patologia
2.
Pulmonology ; 2023 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-37543524

RESUMO

INTRODUCTION: Adherence to controller medication is a major problem in asthma management, being difficult to assess and tackle. mHealth apps can be used to assess adherence. We aimed to assess the adherence to inhaled corticosteroids+long-acting ß2-agonists (ICS+LABA) in users of the MASK-air® app, comparing the adherence to ICS+formoterol (ICS+F) with that to ICS+other LABA. MATERIALS AND METHODS: We analysed complete weeks of MASK-air® data (2015-2022; 27 countries) from patients with self-reported asthma and ICS+LABA use. We compared patients reporting ICS+F versus ICS+other LABA on adherence levels, symptoms and symptom-medication scores. We built regression models to assess whether adherence to ICS+LABA was associated with asthma control or short-acting beta-agonist (SABA) use. Sensitivity analyses were performed considering the weeks with no more than one missing day. RESULTS: In 2598 ICS+LABA users, 621 (23.9%) reported 4824 complete weeks and 866 (33.3%) reported weeks with at most one missing day. Higher adherence (use of medication ≥80% of weekly days) was observed for ICS+other LABA (75.1%) when compared to ICS+F (59.3%), despite both groups displaying similar asthma control and work productivity. The ICS+other LABA group was associated with more days of SABA use than the ICS+F group (median=71.4% versus 57.1% days). Each additional weekly day of ICS+F use was associated with a 4.1% less risk in weekly SABA use (95%CI=-6.5;-1.6%;p=0.001). For ICS+other LABA, the percentage was 8.2 (95%CI=-11.6;-5.0%;p<0.001). CONCLUSIONS: In asthma patients adherent to the MASK-air app, adherence to ICS+LABA was high. ICS+F users reported lower adherence but also a lower SABA use and a similar level of control.

3.
Pulmonology ; 29(4): 292-305, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36428213

RESUMO

BACKGROUND: The self-reporting of asthma frequently leads to patient misidentification in epidemiological studies. Strategies combining the triangulation of data sources may help to improve the identification of people with asthma. We aimed to combine information from the self-reporting of asthma, medication use and symptoms to identify asthma patterns in the users of an mHealth app. METHODS: We studied MASK-air® users who reported their daily asthma symptoms (assessed by a 0-100 visual analogue scale - "VAS Asthma") at least three times (either in three different months or in any period). K-means cluster analysis methods were applied to identify asthma patterns based on: (i) whether the user self-reported asthma; (ii) whether the user reported asthma medication use and (iii) VAS asthma. Clusters were compared by the number of medications used, VAS asthma levels and Control of Asthma and Allergic Rhinitis Test (CARAT) levels. FINDINGS: We assessed a total of 8,075 MASK-air® users. The main clustering approach resulted in the identification of seven groups. These groups were interpreted as probable: (i) severe/uncontrolled asthma despite treatment (11.9-16.1% of MASK-air® users); (ii) treated and partly-controlled asthma (6.3-9.7%); (iii) treated and controlled asthma (4.6-5.5%); (iv) untreated uncontrolled asthma (18.2-20.5%); (v) untreated partly-controlled asthma (10.1-10.7%); (vi) untreated controlled asthma (6.7-8.5%) and (vii) no evidence of asthma (33.0-40.2%). This classification was validated in a study of 192 patients enrolled by physicians. INTERPRETATION: We identified seven profiles based on the probability of having asthma and on its level of control. mHealth tools are hypothesis-generating and complement classical epidemiological approaches in identifying patients with asthma.


Assuntos
Asma , Aplicativos Móveis , Rinite Alérgica , Humanos , Rinite Alérgica/diagnóstico , Rinite Alérgica/epidemiologia , Asma/diagnóstico , Asma/epidemiologia , Projetos de Pesquisa
4.
J Investig Allergol Clin Immunol ; 33(6): 446-456, 2023 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-36000830

RESUMO

BACKGROUND AND OBJECTIVE: Positive bronchodilator reversibility (BDR) is a diagnostic criterion for asthma. However, patients with asthma may exhibit a negative BDR response. Aim: To describe the frequency of positive and Negative BDR response in patients with severe asthma and study associations with phenotypic characteristics. METHODS: A positive BDR response was defined as an increase in FEV1 >200 mL and >12% upon testing with a short-acting ß-agonist. RESULTS: BDR data were available for 793 of the 2013 patients included in the German Asthma Net (GAN) severe asthma registry. Of these, 250 (31.5%) had a positive BDR response and 543 (68.5%) a egative BDR response. Comorbidities significantly associated with a negative response were gastroesophageal reflux disease (GERD) (28.0% vs 40.0%, P<.01) and eosinophilic granulomatosis with polyangiitis (0.4% vs 3.0%; P<.05), while smoking history (active: 2.8% vs 2.2%; ex: 40.0% vs 41.7%) and comorbid chronic obstructive pulmonary disease (COPD) (5.2% vs 7.2%) were similar in both groups. Patients with a positive BDR response had worse asthma control (median Asthma Control Questionnaire 5 score, 3.4 vs 3.0, P<.05), more frequently reported dyspnea at rest (26.8% vs 16.4%, P<.001) and chest tightness (36.4% vs 26.2%, P<.001), and had more severe airway obstruction at baseline (FEV1% predicted, 56 vs 64, P<.001) and higher fractional exhaled nitric oxide (FeNO) levels (41 vs 33 ppb, P<0.05). There were no differences in diffusion capacity of the lung for carbon monoxide, single breath (% pred, 70% vs 71%). Multivariate linear regression analysis identified an association between positive BDR response and lower baseline FEV1% (P<.001) and chest tightness (P<.05) and a negative association between BDR and GERD (P<.05). CONCLUSION: In this real-life setting, most patients with severe asthma had a negative BDR response. Interestingly, this was not associated with smoking history or COPD, but with lower FeNO and presence of GERD.


Assuntos
Asma , Síndrome de Churg-Strauss , Refluxo Gastroesofágico , Granulomatose com Poliangiite , Doença Pulmonar Obstrutiva Crônica , Humanos , Broncodilatadores/uso terapêutico , Volume Expiratório Forçado/fisiologia , Asma/diagnóstico , Asma/tratamento farmacológico , Asma/epidemiologia , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico
5.
Pneumologie ; 75(4): 259-260, 2021 Apr.
Artigo em Alemão | MEDLINE | ID: mdl-33711848

RESUMO

Patients with asthma should be vaccinated against COVID-19. This includes patients with severe asthma. Treatment with a biological for asthma is no contra-indication for vaccination against COVID-19.


Assuntos
Asma , COVID-19 , Pneumologia , Asma/tratamento farmacológico , Áustria , Vacinas contra COVID-19 , Humanos , SARS-CoV-2 , Vacinação
6.
Pneumologie ; 75(3): 191-200, 2021 Mar.
Artigo em Alemão | MEDLINE | ID: mdl-33728628

RESUMO

The present addendum of the guideline for the diagnosis and treatment of asthma (2017) complements new insights into the diagnosis and management of asthma as well as for the newly approved drugs for the treatment of asthma. Current, evidence-based recommendations on diagnostic and therapeutic approaches are presented for children and adolescents as well as for adults with asthma.


Assuntos
Asma , Pneumologia , Adolescente , Adulto , Asma/diagnóstico , Asma/tratamento farmacológico , Asma/epidemiologia , Áustria , Criança , Humanos , Sociedades Médicas
7.
J Vet Cardiol ; 34: 73-79, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33611234

RESUMO

OBJECTIVES: To compare the atrial fibrillatory rate (AFR) derived from a local right atrial intracardiac recording (RA-FR) and from a single-lead surface electrocardiogram (ECG) during atrial fibrillation (AF) and to evaluate the correlation with transvenous electrical cardioversion (TVEC) threshold (in Joules), number of shocks and cardioversion success rate in horses. ANIMALS: ECGs and clinical records of horses with AF treated by TVEC. Horses were included if a simultaneous recording of the right atrial intracardiac electrogram and a modified base-apex ECG were available. MATERIALS AND METHODS: Clinical records of horses with AF treated by TVEC were reviewed. Three-minute long episodes of simultaneous electrograms and surface ECG during AF were selected for analysis and compared using Bland-Altman analysis. The mean RA-FR was measured from the deflections on the intracardiac electrogram, while the AFR was extracted from the surface ECG using spatiotemporal QRS and T-wave cancellation. RESULTS: Seventy-three horses satisfied the inclusion criteria. The mean difference between RA-FR and AFR was -13 fibrillations per minute (fpm), the 95% limits of agreement were between -66 and 40 fpm, and there was a moderate (ρ = 0.65) correlation between RA-FR and AFR (p < 0.001). Neither RA-FR nor AFR appeared to influence the TVEC cardioversion threshold or the number of TVEC shocks applied. CONCLUSIONS: The AFR may allow non-invasive long-term monitoring of AF dynamics. Neither RA-FR nor AFR could be used to predict the minimal defibrillation threshold for TVEC.


Assuntos
Fibrilação Atrial , Doenças dos Cavalos , Animais , Fibrilação Atrial/terapia , Fibrilação Atrial/veterinária , Cardioversão Elétrica/veterinária , Eletrocardiografia/veterinária , Átrios do Coração , Doenças dos Cavalos/terapia , Cavalos
8.
Laryngorhinootologie ; 99(10): 676-679, 2020 10.
Artigo em Alemão | MEDLINE | ID: mdl-32823368
10.
Clin Radiol ; 75(1): 78.e1-78.e7, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31587801

RESUMO

AIM: To develop a robust open-source method for fully automated extraction of total lung capacity (TLC) from computed tomography (CT) images and to demonstrate its integration into the clinical workflow. MATERIALS AND METHODS: Using only open-source software, an algorithm was developed based on a region-growing method that does not require manual interaction. Lung volumes calculated from reconstructions with different kernels (TLCCT) were assessed. To validate the algorithm calculations, the results were correlated to TLC measured by pulmonary function testing (TLCPFT) in a subgroup of patients for which this information was available within 3 days of the CT examination. RESULTS: A total of 288 patients were analysed retrospectively. Manual review revealed poor segmentation results in 13 (4.5%) patients. In the validation subgroup, the correlation between TLCCT and TLCPFT was r=0.87 (p<0.001). Measurements showed excellent agreement between the two reconstruction kernels with an intraclass correlation coefficient (ICC) of 0.99. Calculation of the volumes took an average of 5 seconds (standard deviation: 3.72 seconds). Integration of the algorithm into the departments of the PACS environment was successful. A DICOM-encapsulated PDF document with measurements and an overlay of the segmentation results was sent to the PACS to allow the radiologists to detect false measurements. CONCLUSIONS: The algorithm developed allows fast and fully automated calculation of lung volume without any additional input from the radiologist. The algorithm delivers excellent segmentation in >95% of cases with significant positive correlations between lung volume on CT and TLC on PFT.


Assuntos
Algoritmos , Medidas de Volume Pulmonar/métodos , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Radiografia Torácica/métodos , Tomografia Computadorizada por Raios X/métodos , Feminino , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Testes de Função Respiratória , Estudos Retrospectivos , Software
11.
Pneumologie ; 73(1): 24-33, 2019 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-30308693

RESUMO

In 2017 an amendment to the German transplant law concerning organ allocation and waiting list management became effective. This implies important consequences on lung transplant centers. Crucial innovations concern the transplant conference, indications for lung transplantation and waiting list management. Certain medical conditions now imply a restriction of waiting list enrollment for patients and there are new options for size-matching of donor lung and recipient. Moreover, the new amendment describes in detail how the clinical parameters, on which the lung allocation score (LAS) is based, are defined and how the essential physical examinations have to be performed. Furthermore, the current article provides a summary of the process of organ allocation by the organ exchange organization.


Assuntos
Transplante de Pulmão/estatística & dados numéricos , Obtenção de Tecidos e Órgãos/estatística & dados numéricos , Humanos , Listas de Espera
12.
J Vet Pharmacol Ther ; 41(4): 536-545, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29566261

RESUMO

The long QT syndrome (LQTS) is a channelopathy that can lead to severe arrhythmia and sudden cardiac death. Pharmacologically induced LQTS is caused by interaction between drugs and potassium channels, especially the Kv 11.1 channel. Due to such interactions, numerous drugs have been withdrawn from the market or are administered with precautions in human medicine. However, some compounds, such as trimethoprim-sulfonamide combinations are still widely used in veterinarian medicine. Therefore, we investigate the effect of trimethoprim-sulfadiazine (TMS), trimethoprim, sulfadiazine, and detomidine on equine-specific Kv 11.1 channels. Kv 11.1 channels cloned from equine hearts were heterologously expressed in Xenopus laevis oocytes, and whole cell currents were measured by two-electrode voltage-clamp before and after drug application. TMS blocked equine Kv 11.1 current with an IC50 of 3.74 mm (95% CI: 2.95-4.73 mm) and affected the kinetics of activation and inactivation. Similar was found for trimethoprim but not for sulfadiazine, suggesting the effect is due to trimethoprim. Detomidine did not affect equine Kv 11.1 current. Thus, equine Kv 11.1 channels are also susceptible to pharmacological block, indicating that some drugs may have the potential to affect repolarization in horse. However, in vivo studies are needed to assess the potential risk of these drugs to induce equine LQTS.


Assuntos
Canal de Potássio ERG1/efeitos dos fármacos , Imidazóis/farmacologia , Sulfadoxina/farmacologia , Trimetoprima/farmacologia , Animais , Combinação de Medicamentos , Eletrodos , Eletrofisiologia , Cavalos , Imidazóis/efeitos adversos , Oócitos/efeitos dos fármacos , Oócitos/fisiologia , Técnicas de Patch-Clamp/veterinária , Sulfadoxina/efeitos adversos , Trimetoprima/efeitos adversos , Xenopus laevis
13.
Pneumologie ; 72(4): 253-308, 2018 Apr.
Artigo em Alemão | MEDLINE | ID: mdl-29523017

RESUMO

This document is a revision of the guideline for diagnosis and treatment of COPD that replaces the version from 2007. A multitude of recent reports regarding risk factors, diagnosis, assessment, prevention and pharmacological as well as non-pharmacological treatment options made a major revision mandatory. The new guideline is based on the GOLD document taking into account specifics in Germany and Austria.


Assuntos
Doença Pulmonar Obstrutiva Crônica/diagnóstico , Doença Pulmonar Obstrutiva Crônica/terapia , Pneumologia/normas , Sociedades Médicas , Áustria , Medicina Baseada em Evidências , Alemanha , Humanos
14.
Clin Respir J ; 12(3): 1106-1117, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28398662

RESUMO

OBJECTIVES: The influence of blood group antigens on cancerogenesis is shown for distinct tumor types, yet the impact of Rhesus blood group antigens in lung cancer is not clarified. MATERIALS AND METHODS: To investigate the impact of Rhesus blood groups a non-small cell lung cancer (NSCLC) collective (n = 1047) was analyzed retrospectively. Using a second cohort of n = 340 primarily operated stage I-III NSCLC patients, we evaluated immunohistochemistry of CD47-antibody stained tissue samples in correlation to histopathologic subtype and Rhesus blood group. RESULTS AND CONCLUSION: In 516 of 1047 patients blood group data were available. Seven different RhCE phenotypes were grouped as "··ee," "ccE·," and "C·E·." Adenocarcinoma patients with Rh "··ee" revealed improved overall survival (29 (21.2-36.8) m; HR 1.00 [index]) compared with Rh "ccE·" (19 (1.9-36.1) m; HR 1.76 [1.15-2.70]) and Rh "C·E·" (10 (7.4-12.6) m; HR 2.65 [1.70-4.12]) univariately (P < .001) and multivariately (P < .001). Rh "··ee" showed reduced incidence of CNS-metastasis (P = .014) and metastasis count (P = .032) in stage IV adenocarcinoma. Immunohistochemistry associated CD47-positivity with adenocarcinomas (n = 340, P = .048). In n = 51 cases blood group data were available. The prognostic effect of Rh "··ee" compared with Rh "ccE·" and Rh "C·E·" was stated (P = .001), foremost in CD47-positive adenocarcinomas (Rh "··ee" vs. Rh "ccE·" and Rh "C·E·," P = .008). Inversely Rh "ccE·" or Rh "C·E·" was found beneficial in CD47-negative non-adenocarcinomas (P = .046). Phenotypic RhCE expression may be an independent prognostic factor for overall survival in adeno-NSCLC. We hypothesize an erythrocytic-immunologic interaction with tumor tissue, possibly altered by RhCE and CD47, resulting in a metastatic prone condition.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/sangue , Eritrócitos/metabolismo , Neoplasias Pulmonares/sangue , Estadiamento de Neoplasias , Sistema do Grupo Sanguíneo Rh-Hr/biossíntese , Biomarcadores Tumorais/biossíntese , Biomarcadores Tumorais/sangue , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Progressão da Doença , Feminino , Alemanha/epidemiologia , Humanos , Imuno-Histoquímica , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/mortalidade , Masculino , Pessoa de Meia-Idade , Prognóstico , Taxa de Sobrevida/tendências
15.
Pneumologie ; 71(12): 849-919, 2017 12.
Artigo em Alemão | MEDLINE | ID: mdl-29216678

RESUMO

The present guideline is a new version and an update of the guideline for the diagnosis and treatment of asthma, which replaces the previous version for german speaking countries from the year 2006. The wealth of new data on the pathophysiology and the phenotypes of asthma, and the expanded spectrum of diagnostic and therapeutic options necessitated a new version and an update. This guideline presents the current, evidence-based recommendations for the diagnosis and treatment of asthma, for children and adolescents as well as for adults with asthma.


Assuntos
Asma/diagnóstico , Asma/terapia , Asma/classificação , Asma/etiologia , Áustria , Alemanha , Humanos , Prognóstico , Fatores de Risco , Sociedades Médicas
17.
Clin Exp Allergy ; 47(2): 161-175, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28036144

RESUMO

Asthma is a complex respiratory disorder characterized by marked heterogeneity in individual patient disease triggers and response to therapy. Several asthma phenotypes have now been identified, each defined by a unique interaction between genetic and environmental factors, including inflammatory, clinical and trigger-related phenotypes. Endotypes further describe the functional or pathophysiologic mechanisms underlying the patient's disease. type 2-driven asthma is an emerging nomenclature for a common subtype of asthma and is characterized by the release of signature cytokines IL-4, IL-5 and IL-13 from cells of both the innate and adaptive immune systems. A number of well-recognized biomarkers have been linked to mechanisms involved in type 2 airway inflammation, including fractional exhaled nitric oxide, serum IgE, periostin, and blood and sputum eosinophils. These type 2 cytokines are targets for pharmaceutical intervention, and a number of therapeutic options are under clinical investigation for the management of patients with uncontrolled severe asthma. Anticipating and understanding the heterogeneity of asthma and subsequent improved characterization of different phenotypes and endotypes must guide the selection of treatment to meet individual patients' needs.


Assuntos
Asma/etiologia , Asma/metabolismo , Células Th2/imunologia , Células Th2/metabolismo , Animais , Asma/patologia , Asma/terapia , Biomarcadores , Citocinas/metabolismo , Humanos , Inflamação/imunologia , Inflamação/metabolismo , Inflamação/patologia , Inflamação/terapia , Mediadores da Inflamação/metabolismo , Transdução de Sinais , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo
19.
J Vet Intern Med ; 30(4): 1260-9, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27305095

RESUMO

BACKGROUND: Prolonged exercise in human athletes is associated with transient impairment of left ventricular (LV) function, known as cardiac fatigue. Cardiac effects of prolonged exercise in horses remain unknown. OBJECTIVES: To investigate the effects of prolonged exercise on LV systolic and diastolic function in horses. ANIMALS: Twenty-six horses competing in 120-160 km endurance rides. METHODS: Cross-sectional field study. Echocardiography was performed before and after rides, and the following morning, and included two-dimensional echocardiography, anatomical M-mode, pulsed-wave tissue Doppler imaging, and two-dimensional speckle tracking. Correlation between echocardiographic variables and cardiac troponin I was evaluated. RESULTS: Early diastolic myocardial velocities decreased significantly in longitudinal (baseline: -17.4 ± 2.4cm/s; end of ride: -15.8 ± 3.2cm/s (P = .013); morning after: -15.4 ± 3.0cm/s (P = .0033)) and radial directions (-32.8 ± 3.4cm/s; -28.1 ± 5.8cm/s (P < .001); -26.4 ± 5.5cm/s (P < .001)). Early diastolic strain rates decreased significantly in longitudinal (1.58 ± 0.27s(-1) ; 1.45 ± 0.26s(-1) (P = .036); 1.41 ± 0.25s(-1) (P = .013)) and circumferential directions (2.43 ± 0.29s(-1) ; 1.96 ± 0.46s(-1) (P < .001); 2.11 ± 0.32s(-1) (P < .001)). Systolic variables showed ambiguous results. No correlations with serum cardiac troponin I concentrations were evident. CONCLUSIONS AND CLINICAL IMPORTANCE: Prolonged exercise in horses is associated with impaired LV diastolic function. Reduced ventricular filling persisted for 7-21 hours despite normalization of biochemical indicators of hydration status, indicating that the observed changes were not entirely related to altered preload conditions. The clinical relevance of cardiac fatigue in horses remains uncertain.


Assuntos
Cavalos/fisiologia , Condicionamento Físico Animal/fisiologia , Resistência Física/fisiologia , Função Ventricular Esquerda/fisiologia , Animais , Feminino , Masculino , Esportes , Fatores de Tempo
20.
J Vet Cardiol ; 18(3): 255-264, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27068842

RESUMO

OBJECTIVES: Quantitative measurements of cardiac repolarization, defined as the electrocardiographic QT interval, have important diagnostic implications in humans, as irregularities can trigger potentially fatal ventricular tachyarrhythmia. In both humans and horses, cardiac repolarization is influenced to some extent by heart rate, age, body weight (BW), sex, autonomic tone, and environment. In horses, there is substantial inter-breed variation in size and training, and the aims of this study were therefore to determine the best model describing the QT to RR relationship in breeds of various athletic horses and to test for differences in the QT interval. ANIMALS: Ten Icelandic horses, 10 Arabian horses, 10 Thoroughbreds, 10 Standardbreds, six Coldblood trotters, 10 Warmbloods (dressage) and 10 Warmbloods (show jumping). All horses were geldings. METHODS: QT intervals were measured from resting to peak exercise level and plotted against RR intervals. Data points were fitted with relevant regression models, and the effect of breed, BW, and estimated exercise intensity was examined. RESULTS: For all breeds in this study, the QT interval was best described as a function of RR by the piecewise linear regression model. The breed of horse had a significant effect on the model. There was no systematic effect of BW or estimated exercise intensity, but a high inter-horse variability was observed. CONCLUSIONS: The equine QT interval should preferably be corrected for heart rate according to breed. In addition, the results indicate that equine studies of the QT interval must be designed to eliminate the influence of a large inter-horse variation.


Assuntos
Eletrocardiografia/veterinária , Coração/fisiologia , Cavalos/fisiologia , Esforço Físico/fisiologia , Descanso/fisiologia , Animais , Feminino , Frequência Cardíaca , Masculino , Especificidade da Espécie
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