La enfermedad infecciosa causada por el nuevo coronavirus-2019 (COVID-19), produce un síndrome respiratorio agudo con implicaciones significativas en el sistema cardiovascular tanto en los pacientes con enfermedad cardiovascular preexistente (ECV), que poseen un riesgo de empeoramiento de su enfermedad y muerte, como en los que la infección se ha asociado con múltiples complicaciones directas e indirectas cardiovasculares. Las complicaciones cardiovasculares asociadas con más frecuencia a esta entidad incluyen lesión aguda del miocardio, miocarditis, síndromes coronarios agudos, arritmias y tromboembolismo venoso. Por otra parte, las terapias empleadas para el tratamiento de la enfermedad por COVID-19 pueden tener interacciones medicamentosas con los fármacos cardiovasculares ensombreciendo el pronóstico de los pacientes. El artículo resalta las distintas recomendaciones expuestas por expertos en la literatura médica respecto a las complicaciones cardiovasculares relacionadas con el nuevo coronavirus (COVID-19). 

Introduction: The cardiovascular responses to exercise is mediated by several interactive neural mechanisms including central command, arterial baroreflex and skeletal muscle mechano- and metaboreflex. In humans, muscle metaboreflex activation can be isolated via post-exercise ischemia (PEI) which increases sympathetic nerve activity and partially maintains the exercise-induced increase in arterial blood pressure (BP). Although skeletal muscle metaboreflex is considered one of the principal mediators of the cardiovascular response to exercise, PEI was widely used in scientific reports, but its use as a tool for teaching cardiovascular physiology has not been previously reported.

Objective: To describe a practical lesson methodology used in an undergraduate exercise physiology laboratory class that can guide teachers to demonstrate several aspects of cardiovascular regulation during exercise and report the perceptions of the students after the laboratory class.

Material and Methods:  We hypothesized that our practical laboratory class will improve the student’s perceptions of their understanding of the cardiovascular regulation during exercise. In an undergraduate exercise physiology class (n=47), a traditional 4-h lecture was conducted discussing the neural control mechanisms of cardiovascular regulation during exercise. Thereafter, eight students (4 men and 4 women) were selected to participate as a volunteer of a practical laboratory class. Each participant performed 90 s of isometric handgrip (IHG) exercise at 40% of maximal voluntary contraction followed by 3 min of PEI. Arterial BP and heart rate were measured by digital monitors at rest, during IHG, PEI and recovery. In addition, blood samples were collected from the tip of the exercising finger for blood lactate analyses. After the laboratory class, a survey was given to determine the perceptions of the students through a questionnaire consisting of 10 items on a 5-point Likert scale.

Results: The findings demonstrate that, before the laboratory class, some students were not confident of their understanding of cardiovascular regulation during exercise. Overall, the students self-related that the activity improved their level of understanding regarding 1) the cardiovascular responses to exercise; 2) the role of skeletal muscle metaboreflex as an important mediator of cardiovascular responses to exercise; 3) the role of blood lactate as a trigger of muscle metaboreflex activation; and 4) the sex-related differences in cardiovascular responses to exercise. In addition, the majority of students believed that the activity reinforced their appreciation for the importance of the subject matter, enhanced their desire to learn the subject matter, and improved their approach for studying the content for the course exam. In summary, this laboratory class has proved to be highly popular with students, who self-reported a significant improvement in their understanding of several aspects of cardiovascular regulation during exercise.

Conclusions: These findings could encourage exercise physiology teachers to incorporate the use of PEI as a tool for teaching cardiovascular physiology for undergraduate students.

Introduction: Cardiovascular disease is an important cause of death in commercial turkeys, meat-type chicken and other birds. Spontaneous turkey cardiomyopathy (STC; round heart), ruptured aorta and sudden death account for over 50% of the "normal" mortality in tom turkeys. Flip-over (sudden death syndrome) and pulmonary hypertension, leading to right ventricular failure, cause high losses in broiler and roaster chickens. In both chickens and turkeys these condition are related directly to growth rate. The diagnosis is usually based on history and gross examination. This work was designed to assess the electrocardiographic (ECG) parameters of various birds as alternative/additional means of clinical diagnosis.

Objective: To identify every aspect of the Lead II ECG wave form. The electrocardiogram is a useful tool in avian medicine as it can be utilized to measure heart rate and to detect arrhythmias, cardiac chamber enlargement, and electrical conductance abnormalities

Method: EDAN 10 Veterinary electrocardiographic equipment made in China; with a 200 mm/s paper speed and a sensitivity of 100 mm/mV was used to measure the ECG. The five alligator clip electrodes were fixed directly to the skin under the feather- on the forearms (muscular part of the wing), on the hind limbs above the stifle joint, and the heart as described earlier by Azeez et al, (2017). The EDAN was connected to the laptop and information about each bird was recorded and saved. Birds considered include Turkey, Chinese geese, Laying birds (chicken), point of lay birds and domestic ducks. They were all carefully restrained. 5 birds from each group was used

Results: The ECG exhibited positive P wave, inverted (Q) RS and positive T wave in all of them. S-S interval was regular in turkey and duck, irregular in chicken and Chinese geese. The PR interval in the Laying birds and Broilers were very longer with overlap by QRS. The (Q) RS was shorter (29-44ms) in the chicken with very short amplitude, longer (50-65ms) in turkey and duck with longer amplitude. No significant difference in the QRS within the groups. QT interval was longer in turkey, geese and duck (297-456ms) but shorter in chicken.

Introducción: Hace años, Cuba, en su Anuario Estadístico de Salud, viene presentando las enfermedades del corazón como la primera causa de muerte. Asociados a la morbimortalidad cardiovascular se encuentran el sobrepeso y la obesidad, también identificados por la American Heart Association como uno de los mayores e independientes factores de riesgo cardiovascular. Desde entonces, varios estudios han relacionado el aumento de peso con modificación de la morfofunción del corazón.

Objetivo: Describir las modificaciones del patrón geométrico del ventrículo izquierdo y de la función cardiaca asociadas a malnutrición por exceso en sujetos de la provincia La Habana.

Métodos: Se estudiaron 72 sujetos de ambos sexos, aparentemente sanos, que acudieron al Hospital Calixto García a chequearse. A todos se les realizó anamnesis, examen físico, se midió el porcentaje de grasa corporal utilizando un equipo de bioimpedancia; esto permitió clasificar a los sujetos en tres grupos: grupos N (normal), A (alto) y MA (muy alto) y un ecocardiograma. Se procedió a comparar los grupos entre sí mediante análisis estadístico.

Resultados: En 23 sujetos con porcentaje de grasa corporal superior al normal, predominó el remodelado concéntrico del ventrículo izquierdo. A mayor composición de grasa corporal aumentó la frecuencia de relajación prolongada, comprometiendo la función diastólica y decreció ligeramente la fracción de eyección del ventrículo izquierdo.

Conclusiones: En asociación con el aumento en el porcentaje de grasa corporal hubo cambios morfológicos del corazón, destacando la remodelación concéntrica y el deterioro de la función diastólica.

Introduction: Cardiovascular diseases are still the main cause of mortality all over the world.  Ischemic heart conditions are very well know, but aneurysmatic diseases. Endothelial damage seems to be the key in this illness. Objective. According to its importance, new risk factors and specifically biomarkers are needed. Methods: After looking for information in several databases such us: Medline- PubMed, Cochrane and Scielo, a review was done. Results: According literature, arterie’s conditions remain at the top ten cause of death of many countries such as Cuba were 2938 defunctions were registered during 2016. This condition importance is due to asymptomatic featuring so, when pain appears usually fatal complications just like dissection or rupture are presented. Through de major factors involved in this pathology aging, male sex, hypertension and left ventricular mass index ere described. Many biochemical parameters seem to be also coinvolved:  uric acid concentration, total reductive antioxidant capacity are some of them. Another proposed biomarkers are thioredoxin 1, peroxiredoxin 1 and iron. There is not still strong information about NOX4 or ROS, even though its role as a main actor in endothelial lesion through oxidative stress is very well known. Conclusion: Scientific community has realized about oxidative stress role according aneurysmatic diseases. Therefore, antioxidants could be an appropriate method for early diagnosis, follow-up evaluation and target therapy, but molecular studies are not still enough.

Introducción: La mitad de las muertes cardiovasculares son debidas a una de las manifestaciones de mayor impacto y significación dentro de la enfermedad isquémica del corazón: la muerte súbita cardiovascular.

Objetivo: Describir el Algoritmo Diagnóstico y el Modelo de Recolección del Dato Primario utilizados como instrumentos para la investigación de la muerte súbita cardiovascular en Cuba.

Métodos: Se presenta un Algoritmo Diagnóstico con la metodología para el estudio de los casos de muerte súbita cardiovascular y un Modelo de Recolección del Dato Primario con las principales variables sociodemográficas, clínicas y anatomo-patológicas.

Resultados: El Grupo de Investigación en Muerte Súbita ha desarrollado, en un periodo de 25 años (1995-2020), investigaciones científicas con la aplicación del Algoritmo Diagnóstico y el empleo del Modelo de Recolección del Dato Primario. De las 33 718 muertes naturales estudiadas mediante estos instrumentos, se han documentado 2252 decesos súbitos, lo que representa el 6,6 % de la mortalidad global registrada.

Conclusiones: Se hace necesario por los colectivos de investigación disponer de instrumentos que permitan ejecutar estudios poblacionales sobre la muerte súbita cardiovascular, considerando que el 90 % de los eventos anualmente sobreviene en este grupo.

Introduction: a number of adjustments of the cardiovascular system are required during isometric exercise; variations in the components involved in young people blood pressure response result controversial.

Objective: to determine the difference between gender at baseline hemodynamic parameters and during isometric Sustained Weight Test in normorreactive, hyperreactive and with hypertensive response young people.

Methods: sample was constituted by 97 young people of both genders, 41 males and 56 females, with an average age of 19±1,40 years, whom was applied hemodynamic monitoring in supine decubitus position with non-invasive by impedance cardiography at rest and while the sustained weight test was performed.

Results: significantly superior values of heart rate and cardiac index were obtained in normorreactive women in basal conditions, and at the exercise. Normorreactive male had significantly higher systemic vascular resistance index than females in both conditions and the hypertensive response group had differences only in the exercise. Women achieved higher heart rate increments than men during isometric exercise. Systemic vascular resistance index were increased in all groups of both genders, mainly in normorreactive men.

Conclusions: at baseline, women had higher values of hemodynamic variables related to cardiac activity and men related to vascular tone. Differences between both genders remained during isometric exercise, and the increased blood pressure was mainly due to the increase of systemic vascular resistance.

Introducción: Las enfermedades cardiovasculares constituyen la principal causa de mortalidad y morbilidad a nivel mundial. Reconocidas como problemas de salud de impacto social, han motivado a muchos científicos a tratar de explicar su patogénesis. Actualmente se plantea de la existencia de otros factores de riesgo, independientemente de los clásicos. Entre estos factores se describen el papel de las altas concentraciones de ácido úrico y la actividad de la enzima gamma-glutamiltransferasa en sangre, biomarcadores de estrés oxidativo. Estos elementos que de manera individual pudieran contribuir a las enfermedades cardiovasculares, parecen tener un efecto sinérgico.

Objetivo: Revisar las evidencias que sostienen que altas concentraciones de ácido úrico y la actividad de la enzima gamma-glutamiltransferasa en sangre pueden constituir factores de riesgo que desde el estrés oxidativo contribuyan a las enfermedades cardiovasculares.

Métodos: Se recopiló la información a partir de las bases de datos de diferentes buscadores (Medline-Pubmed, Cochrane, Scopus y SciELO) entre el 1 de marzo del 2019 y el 23 de mayo 2020.

Conclusiones: Se encontró que, tanto el ácido úrico como la gamma-glutamiltransferasa son productos horméticos que a bajas concentraciones tienen efecto antioxidante en el organismo, pero al elevarse involucran la ocurrencia de procesos oxidativos que conducen a la disfunción endotelial y las enfermedades cardiovasculares.

Introduction: the autonomic nervous system plays an important role in cardiovascular readjustments to exercise. In cardiovascular hyperreactivity there is a greater sensitivity of the sympathetic system to different stressors.  Objective: to determine the characteristics of cardiac autonomic control in young adults with different degrees of cardiovascular reactivity at rest and during isometric exercise. Material and Methods: the sample consisted of 97 individuals of both sexes, it was divided into three groups; normorreactives, hyperreactive and with hypertensive response according to the pressor response to the sustained weight test. All individuals underwent a variability study of heart rate at rest and during the isometric test. Variables in the frequency domain were studied: HF, LF, resting LF/HF ratio and the parameters of the Poincaré diagram SD1, SD2 and the SD1/SD2 ratio at rest and during exercise.  Results: At the basal state, hyperreactive individuals and with a hypertensive response had a sympathetic predominance over cardiac function and a lower variability of heart rate. During isometric exercise the values of the SD1 and SD2 axes decreased in all groups and the SD1/SD2 ratio decreased in normorreactive individuals and with hypertensive response, but it was only significantly in the hyperreactive ones. Conclusions: In individuals with cardiovascular hyperreactivity, an autonomic imbalance is already present in the basal state and there is a reduction in autonomic vagal modulation during exercise that may contribute to the development of hypertension.

Introducción: Las enfermedades cardiovasculares representan en la actualidad la principal causa de muerte y discapacidad en numerosos países, incluyendo los de nuestro continente, alrededor del 49% de las defunciones de manera global en el año 2019 fueron por esta causa.

Métodos: Estudio descriptivo de corte transversal con componente analítico, de todos los pacientes ingresados en la Unidad de Cuidados Coronarios Intensivos del Hospital Universitario “Manuel Fajardo” de la Habana entre el año 2016 y el 2020 con el diagnóstico de síndrome coronario agudo con elevación del segmento ST.

Resultados: La edad y el valor de la CKMB resultaron predictores independientes de complicaciones cardiovasculares de cualquier tipo: (OR: 1,045, IC 95 %: 1,021-1,070; p<0,001 y OR: 1,004, IC 95 %: 1,001-1007; p=0,015) respectivamente.

Conclusiones: La edad, y los valores elevados de las enzimas cardíacas constituyeron predictores independientes de complicaciones cardiovasculares de cualquier tipo, así como el sexo femenino y la FEVI; la edad, los antecedentes de diabetes mellitus y la terapia de reperfusión para el caso particular de las complicaciones hemodinámicas y eléctricas respectivamente.

Objetivo: Evaluar los indicadores antropométricos de obesidad para capacidad predictiva de riesgo cardiovascular (RCV) en una muestra de pobladores peruanos.

Métodos: Estudio de pruebas diagnósticas. Análisis de bases secundario del estudio PERU MIGRANT. EL RCV se midió según la escala de Framingham por D'Agostino (SFA). Se evaluaron 6 índices de obesidad: circunferencia abdominal, índice de masa corporal, índice de forma corporal (IFC), índice de redondez corporal (IRC), índice de conicidad, relación cintura altura y relación cintura cadera (RCC). La capacidad discriminativa de los modelos se probó utilizando áreas bajo curvas (AUC) con su intervalo de confianza al 95% (IC 95%).

Resultados: La prevalencia de RCV bajo fue del 60,70%. En varones, el AUC más alto lo presentó el IRC: 0,755, valor de corte = 4,78; sensibilidad = 59,0% y especificidad = 76,4%. En mujeres, el AUC más alto lo obtuvo RCC: 0,694; valor de corte = 0,91, sensibilidad = 73,3%  y especificidad = 61,0.

Conclusiones: El IRC y el RCC fueron los parámetros antropométricos con mayor capacidad predictiva para el sexo masculino y femenino, respectivamente. Sin embargo, dados sus valores bajo, es probable que estos índices de obesidad no alcancen a ser suficientes para predecir RCV como lo hace el SFA.