Electrocardiographic changes and changes in cardiac lactate and troponin I levels associated with search and rescue physical activity in military dogs / Alterações eletrocardiográficas e nos níveis de lactato e troponina I cardíaca associadas à atividade física de busca e salvamento em cães militares

Rescue and recovery dogs intercalate the activity intensity developed, which also triggers significant metabolic changes in cardiac physiology. Thus, we evaluated the changes that search simulation causes in glucose, lactate, and cardiac troponin I level (cTnI) and the electrocardiographic and heart rate during the activity and recovery phase to predict the physiological adaptation to the exercise. Five healthy adult dogs from the Rescue and Recovery Service of Military Firefighters Corps were submitted to 60 minutes search operation simulation in the woods. They covered a forest area of approximately 50,000 m2. The dogs were loose and accompanied by their driver, and they could perform any physical activity. Were evaluated serum biochemical analysis of glucose, lactate, cardiac troponin I, electrocardiographic, and heart rate (rest, exercise phase, and recovery time). No changes in glucose levels, heart rate, and cardiac rhythm were detected. In comparison to baseline values, there is an increase: in lactate at the end of the exercise phase [EXER] (60'EXER), and in the recovery phase [RCT] at 30'RCT and 60'RCT, and cTnI at 60'RCT, 120'RCT, and 4hRCT. P wave duration was significantly higher at 60'EXER, 15'RCT, and 30'RCT, with no alterations in wave amplitude. QRS interval duration significantly increased at 30'RCT, and the ST segment presented a significant difference at 60'EXER, 15'RCT, and 60'RCT compared to the rest moment. The moderate alterations in lactate and cTnI and few alterations in the electrocardiographic and heart rate maintenance suggest the adaptation of rescue and recovery dogs to the type, intensity, and duration of search operation simulation performed.(AU)

Cães de busca e resgate intercalam a intensidade da atividade desenvolvida que desencadeia alterações metabólicas significativas, bem como na fisiologia cardíaca. Assim, foram avaliadas as alterações que a simulação de busca produz nos níveis de glicose, lactato, troponina I cardíaca (cTnI), bem como na frequência cardíaca e atividade eletrocardiográfica durante a fase de atividade e recuperação, a fim de predizer a adaptação fisiológica ao exercício. Cinco cães adultos saudáveis do Serviço de Resgate e Salvamento do Corpo de Bombeiros Militares foram submetidos à simulação de operação de busca de 60 minutos na mata e cobriram uma área florestal de aproximadamente 50.000 m2. Os cães estavam soltos, acompanhados pelo condutor e estavam livres para realizar qualquer tipo de atividade física. Foram avaliados os níveis séricos de glicose, lactato e troponina I cardíaca, atividade eletrocardiográfica e frequência cardíaca em repouso, na fase de exercício e no tempo de recuperação. Não foram detectadas alterações nos níveis de glicose, frequência cardíaca e ritmo cardíaco. Em comparação com os valores basais houve aumento de lactato ao final da fase de exercício [EXER] (60'EXER) e na fase de recuperação [RCT] aos 30'RCT e 60'RCT; e cTnI aos 60'RCT, 120'RCT e 4hRCT. Duração da onda P foi significativamente maior em 60'EXER, 15'RCT e 30'RCT, sem alterações na amplitude da onda. Duração do intervalo QRS teve aumento significativo em 30'RCT e o segmento ST apresentou diferença significativa em 60'EXER, 15'RCT e 60'RCT quando comparado ao basal. As alterações moderadas nos níveis de lactato e cTnI, bem como a pouca alteração na atividade eletrocardiográfica e manutenção da frequência cardíaca sugerem boa adaptação dos cães de busca e resgate ao tipo, intensidade e duração da operação de busca simulada realizada.(AU)

Case Report: Myocardial Bypass in Left Descending Artery - A Rare Congenital Anomaly

Abstract Myocardial bypass (MB) is known to have scientific relevance and is present in several studies with great statistical significance regarding its clinical manifestations and complications. There are still questions about MB in its relationship with heart disease and repercussion in life-threatening conditions. We present a case report of a MB in the left anterior descending coronary artery, whose objective is to identify this rare congenital anomaly and to highlight the patient's clinical outcome in order to elicit greater contributions about the presence of this variant in the emergency room, its diagnosis by angiography and therapeutic management.

Video Caso Clínico: Estimulación Vagal Directa Como Maniobra Electrofisiológica Alternativa en el Diagnóstico de Taquicardia Durante Estudio Electrofisiológico / Case Report: Direct Vagal Stimulation as Alternative Electrophysiological Procedure in the Diagnosis of Tachycardias During Electrophysiological Study

INTRODUCCIÓN: El síndrome de Wolff Parkinson White se caracteriza por la conexión anómala entre la aurícula y el ventrículo durante el paso del estímulo sinusal, generalmente causada por una vía accesoria que conecta el músculo auricular con el músculo ventricular llamado haz de Kent, caracterizándose por la presencia de síntomas como: palpitaciones, sincope o muerte súbita y sumado a la presencia de onda delta, intervalo PR corto, QRS ancho y alteraciones de la repolarización ventricular en el electrocardiograma. El estudio electrofisiológico tiene como objetivo confirmar la presencia, localización y características de este haz anómalo y posteriormente, con seguridad, proceder a la ablación por radiofrecuencia eliminando esta vía accesoria, siendo considerado un procedimiento curativo en el caso del síndrome de Wolff Parkinson White. Durante el estudio se realiza estimulaciones eléctricas en los sitios específicos, tanto de la aurícula como del ventrículo, además se utiliza medicación intravenosa como la adenosina que actúa bloqueando al nódulo aurículoventricular y así observar el paso residual de la estimulación sinusal normal y/o el paso retrogrado del estímulo ventricular hacia la aurícula a través del haz de Kent, permitiendo de esta forma analizar las características de las conexiones aurículoventriculares previo a la ablación. La posibilidad de realizar una estimulación vagal selectiva de alta frecuencia y baja amplitud a nivel infraorbitario, descrita por Pachón et al [1], a través de la vena yugular interna y el consecuente bloqueo aurículoventricular transitorio que esta ocasiona, permite realizar el estudio sin necesidad de utilizar otras maniobras electrofisiológicas o medicación endovenosa

BACKGROUND: Wolff Parkinson White Syndrome is characterized by the bypass of the electrical signal through an abnormal pathway, different from the atrioventricular node that connects the atrial and ventricular muscles (Bundle of Kent). It presents with palpitations, syncope or can even cause sudden death. Electrocardiogram findings consist on Delta waves, shortened PR interval, widened QRS complex and altering of the ventricular repolarization. In the presence of Ventricular pre-excitation (Wolff Parkinson White Syndrome), the electrophysiological testing is key to confirm the presence, site and features of this accessory pathway. Later, with the certainty of the diagnosis proceed to perform the Radiofrequency Ablation, the definitive treatment to eliminate this abnormal pathway. This test is usually done with the use of electrophysiological maneuvers, stimulating key sites in the atria and the ventricle, with the help of intravenous drugs like Adenosine. The objective is to block the AV node to look how the remnants of the normal electrical signal move through the abnormal pathway, thus letting the physician analyze the characteristics previously mentioned of this pathway. After the ablation, these maneuvers are repeated to confirm the complete elimination of the accessory pathway that has direct relation with the prognostic. Based on the possibility of high frequency and low amplitude selective vagal stimulation described by Pachón et al [1], at infraorbital level through the internal jugular vein and the resulting transitory atrioventricular block. It is possible to study the abnormal pathway without the need of electrophysiological maneuvers or the use of IV drugs, either pre or post ablation.

Distúrbios de condução e arritmias na sarcoidose cardíaca - relato de caso / Conduction disturbances and arrhythmias in cardiac sarcoidosis - case report

A forma cardíaca isolada da Sarcoidose é pouco frequente. no entanto, o envolvimento cardíaco na sarcoidose é mais prevalente e ocorre em 5 % desses pacientes. O diagnóstico de sarcoidose cardíaca é um desafio por causa das manifestações inespecíficas, sendo a sensibilidade e especificidade das modalidades diagnósticas limitadas. Este relato de caso teve por objetivo descrever o caso de um paciente sem diagnóstico prévio de sarcoidose com arritmias e distúrbio de condução ventricular compatíveis com acometimento cardíaco da doença. Optou-se para o tratamento um implante de marcapasso definitivo e terapia com corticosteroides

The isolated cardiac form of sarcoidosis is infrequent. However, cardiac involvement in sarcoidosis is more prevalent and occurs in 5% of these patients. The diagnosis of cardiac sarcoidosis is a challenge because of non-specific manifestations, and the sensitivity and specificity of the diagnostic modalities are limited. This case report aimed to describe the case of a patient without previous diagnosis of sarcoidosis with arrhythmias and ventricular conduction disturbance compatible with cardiac involvement of the disease. A definitive pacemaker implant and corticosteroid therapy were chosen for the treatment

Análise crítica dos estudos com os novos anticoagulantes / Critical anlysis of studes on the novel anticoagulantes

Os eventos tromboembólicos são complicações significativas da fibrilação atrial (FA) e podem ser prevenidos com a anticoagulação oral plena. A varfarina reduz em 64% o risco de tromboembolismo, no entanto, a dificuldade no seu manejo clínico motivou a busca por novos anticoagulantes orais (NOACs). Os NOACs inibem especificamente um único fator na cascata da coagulação, têm meia vida curta, efeito previsível e estável, dispensam monitorização e interagem pouco com alimentos e medicamentos.Os estudos RE-LY, ROCKET-AF, ARISTOTLE e ENGAGE AFTIMI48 compararam a varfarina com a dabigratana, rivaroxabana,apixabana e edoxabana, respectivamente, e evidenciaram que os NOACS são equivalentes (dabigatrana 110 mg, rivaroxabana,edoxabana) ou superiores (dabigatrana 150 mg, apixabana) à varfarina na prevenção de tromboembolismo sistêmico ou AVC em pacientes com FA não valvar. Ademais, apresentam índices de hemorragias intracranianas substancialmente menores do quea varfarina. Já a apixabana foi superior à aspirina na prevençãode AVC, com os mesmos índices de sangramento. Os NOACs não devem ser usados em gestantes, crianças, e em pacientes com estenose mitral significativa, próteses valvares ou função renal muito deprimida. Porém, podem ser usados nos cenários de cardioversão e ablação da FA. Ainda não há estudos comparativos entre os diversos NOACs, nem consenso de quando recomendara troca da varfarina em pacientes com RNI estável. Cerca de 50%dos pacientes com FA e indicação de anticoagulação não recebem terapia anticoagulante. Portanto, com advento dos NOACs, a expectativa é reduzir essa parcela, diminuindo a incidência de fenômenos tromboembólicos na FA.

Thromboembolic events are important complications of atrialfibrillation (AF) and can be prevented by oral anticoagulation.Warfarin reduces by 64% the risk of thromboembolism,however, the difficulties in its clinical management promptedthe search for novel oral anticoagulants (NOACs). The NOACsspecifically inhibit a single factor in the coagulation cascade,have a short half-life, predictable and stable effect, do not requiremonitoring and have minor interactions with food and drugs.The RE-LY, ROCKET-AF, ARISTOTLE and ENGAGE AFTIMI48 trials compared warfarin to dabigatran, rivaroxaban,apixaban and edoxaban, respectively, and showed that NOACSare equivalent (110 mg dabigatran, rivaroxaban, edoxaban) orsuperior (dabigatran 150 mg, apixaban) to warfarin in preventingstroke or systemic embolism in patients with nonvalvular AF.Furthermore, they are associated with substantially lower levelsof intracranial bleeding than warfarin. Apixaban was superiorto aspirin in preventing strokes, with the same rate of bleeding.The NOACs should not be used in pregnant women, children,and patients with significant mitral stenosis, prosthetic valvesor impaired renal function. However, these novel drugs can beused in the scenarios of cardioversion and AF ablation. Thereare no studies comparing individual NOACs or consensus aboutswitching patients on warfarin with stable INR. Approximately50% of patients with AF and recommendation for anticoagulationdo not receive anticoagulant therapy. Therefore, with the adventof NOACs, the expectation is to improve this figure, ultimatelydecreasing the incidence of thromboembolic events in AF.

Síndromes de la onda J / J wave syndromes

Se realizó una revisión sobre los aspectos más novedosos y polémicos de los síndromes de la onda J, que incluyó el síndrome de repolarización precoz, la fibrilación ventricular idiopática y la muerte súbita nocturna inexplicable. Se enfatiza en las características electrocardiográficas de estos síndromes donde se destaca la presencia de un supradesnivel del ST tipo cóncavo con melladuras o empastamiento del mismo. Se profundiza en las bases genéticas, a veces común a todos ellos, en particular la mutación SCN5A asociada con el supradesnivel del ST y más recientemente la mutación S422L-KCNJ8 como causa de alteración de los canales I K-ATP, lo cual se asocia con mortalidad arrítmica cardíaca. Se concluye que aunque no todos los pacientes con este síndrome estén en riesgo de eventos arrítmicos o de muerte súbita cardíaca, existe un grupo de ellos no despreciable que sí lo están, por lo que el gran desafío de la comunidad médica es desarrollar mejores estrategias de estratificación de riesgo y desarrollar tratamientos más seguros y eficaces para estos

A review was conducted of the newest and most controversial aspects of J wave syndromes, including early repolarization syndrome, idiopathic ventricular fibrillation and sudden unexplained nocturnal death. Emphasis is made on the ECG features of these syndromes, among them the presence of an upwardly concave ST irregularity with notching or slurring. A detailed analysis is made of genetic bases, which are sometimes common to all syndromes, particularly the SCN5A mutation, associated with the ST upwardly irregularity, and more recently the S422L-KCNJ8 mutation causing the alteration in the lK-ATP channels, associated with arrhythmic cardiac mortality. It is concluded that not all patients with this syndrome are at risk of arrhythmic events or sudden cardiac death, but a significant number of them are. Therefore, a great challenge for the medical community is to develop better risk stratification strategies as well as safer and more effective treatments

Molecular characterization, electrophysiological and contraceptive effect of chilean latrodectus venom / Caracterización molecular, electrofisiológica y efecto anticonceptivo del veneno de latrodectus chilena

Since the 1970s, There have been studies of the venom of Latrodectus sp. spiders, in particular the latrotoxin (LTX) of Latrodectus mactans. Many of the studies were aimed at understanding the action of the venom on the muscular system. Now accepted that LTX is able to generate a calcium-permeable membrane pore and modulate the release of synaptic vesicles that activate a receptor and induce cellular changes. Interestingly, when work began with venom obtained from the Latrodectus sp present in Chile, it generated clinical indications similar to the bite of this spider in another country, with some differences in intensity. The purpose of the first studies was to understand the systemic mechanisms of this venom, and other active compounds were studied for biological interest. It was found that these molecules are capable of causing systemic effects such as changes in muscle contraction; of generating vascular relaxation and synaptic and cellular modulation; and of altering potassium conductance channels. Based on this evidence, we suggested biotechnological applications to characterize low molecular-weight compounds obtained from the Chilean Latrodectus venom and exploring the effects on the electrophysiology in oocytes and neurons, and the contraceptive effect on spermatozoa.

Desde los años 70, se han realizado estudios con el veneno de arañas Latrodectus sp, en particular la latrotoxina (LTX) de Latrodectus mactans. Muchos de estos estudios estuvieron enfocados a entender la acción del veneno sobre el sistema muscular. Hoy en día es aceptado que la LTX es capaz de generar un poro de membrana permeable a calcio y modular la liberación de vesículas sinápticas que activan un receptor e inducen cambios celulares. Interesantemente, cuando comenzamos a trabajar con el veneno obtenido de Latrodectus sp. presente en Chile, ésto generó indicaciones clínicas similares a la picadura de esta araña en otros países, con algunas diferencias en su intensidad. El propósito de estos primeros estudios fue entender los mecanismos sistémicos de este veneno y además otros compuestos activos fueron estudiados para interés biológico. Se ha encontrado que estas moléculas son capaces de causar efectos sistémicos así como cambios en la contracción muscular; generar relajación vascular y modulación sináptica y celular; y de alterar los canales de conductancia de potasio. Basados en estas evidencias, nosotros sugerimos usar aplicaciones biotecnológicas para caracterizar los compuestos de bajo peso molecular obtenidos del veneno de Latrodectus Chilena y explorar los efectos sobre la electrofisiología en ovocitos y neuronas, y el efecto anticonceptivo sobre los espermatozoides.