Carotid body Thermoreceptors, sympathetic neural activation, and cardiometabolic disease

The carotid body (CB) is the main peripheral chemoreceptor that senses the arterial PO2, PCO2 and pH. In response to hypoxemia, hypercapnia and acidosis, carotid chemosensory discharge elicits reflex respiratory, autonomic and cardiovascular adjustments. The classical construct considers the CB as the main peripheral oxygen sensor, triggering reflex physiological responses to acute hypoxemia and facilitating the ventilatory acclimation to chronic hypoxemia at high altitude. However, a growing body of experimental evidence supports the novel concept that an abnormally enhanced CB chemosensory input to the brainstem contributes to overactivation of the sympathetic nervous system, and consequent pathology. Indeed, the CB has been implicated in several diseases associated with increases in central sympathetic outflow. These include hypertension, heart failure, sleep apnea, chronic obstructive pulmonary disease and metabolic syndrome. Indeed, ablation of the CB has been proposed for the treatment of severe and resistant hypertension in humans. In this review, we will analyze and discuss new evidence supporting an important role for the CB chemoreceptor in the progression of autonomic and cardiorespiratory alterations induced by heart failure, obstructive sleep apnea, chronic obstructive pulmonary disease and metabolic syndrome.

Estudio comparativo con doppler triplex y scion image® del sistema carotideo extracraneal / Comparative study with doppler triplex and scion image® of the carotid extracranial system

Comparar Doppler Triplex y Scion Image® para obtener un análisis computarizado de la ecogenicidadque caracteriza cualitativamente a los tejidos estudiados en las imágenes médicas adquiridas. Se examinó la región cervical bilateralmente a una muestra de individuos adultos jóvenes de ambos sexos. Se procedió a realizar un histograma computarizado en una región de interés seleccionada al azar de la arteria carótida común y del músculo esternocleidomastoideo, analizando los datos obtenidos con el método estadístico HOMALS. Se observó que la mediana para los valores altos y bajos en la escala de gris de la arteria carótida común y del músculo esternocleidomastoideo, tiene similitud con la de los valores altos y bajos de la velocidad pico sistólica de la arteria carótida común. Asimismo, la mediana de las variables categóricas correspondientes a la escala de gris de la arteria carótida común y del músculo esternocleidomastoideo, también tiene similitud con la de los valores de la velocidad al final de la diástole de la arteria carótida común. La comparación de Doppler Triplex con Scion Image® es factible, resultando estadísticamente discriminante para el estudio del sistema carotídeo extracraneal.

To compare Doppler Triplex and Scion Image® to obtain a computed analysis of the echogenicity that qualitatively characterizes to the tissues studied in the acquired medical images. It was examined the cervical region bilaterally to a sample of young mature individuals of both sexes. It was proceeded to carry out an computed histogram in a region of interest selected at random of the common carotid artery and the sternomastoid muscle, analyzing the obtained data with the statistical method HOMALS. It was observed that the median for the upper and under values in the grayscale of the common carotid artery and of the sternomastoid muscle, this has similarity with that of the upper and under values of the peak systolic velocity of the common carotid artery. Also, it could be appreciated that the median of the values of the categorical variables corresponding to the grayscale of the common carotid artery and of the sternomastoid muscle, this also has similarity with that of the peak end diastolic velocity of the common carotid artery. The comparison of Doppler Triplex with Scion Image® is feasible, being statistically discriminant for the study of the extracranial carotid system.