jueves, 6 de agosto de 2015

Reflejo BARO-RECEPTOR en Infarto Isquémico, sensibilidad y participación de la ínsula

Estimado Colega:

• La sensibilidad alterada del reflejo BARO-RECEPTOR se ha demostrado que tiene un valor diagnóstico en pacientes con enfermedad cardiovascular e infarto isquémico.




• Los reflejos BARO-RECEPTORES espontáneamente compensan las fluctuaciones de la presión arterial. Los BARO-RECEPTORES son activados por cambios en la presión arterial, ajustan el ritmo cardíaco (Sistema Vagal) y el tono vascular periférico (Sistema Simpático), evitan grandes diferencias de la presión arterial.

• Se localizan en las bifurcaciones de arterias carótidas, arco aórtico, que desafortunadamente son los sitios más frecuentes de placas arterioescleróticas. La arteria con esclerosis afecta estos reflejos, reduciendo la sensibilidad arterial.

• Aparentemente la corteza de la ínsula juega un rol principal en la modulación de la sensibilidad del BARO-RECEPTOR.

• De 780 pacientes con infarto isquémico, únicamente 96 fueron incluidos en el estudio, debido a otros motivos clínicos (hemorragia subaracnoidea, intraventricular, diabetes, etc.)

• El estudio demostró que el reflejo BARO-RECEPTOR es independiente de la arterioesclerosis y que la corteza de la ínsula juega un papel importante en la regulación del reflejo.

Muy atentamente, equipo TecniScan Científico.


Artículo de Rereferencia
Impaired Baroreceptor Reflex Sensitivity in Acute Stroke Is Associated With Insular Involvement, But Not With Carotid Atherosclerosis
Stroke, 2009; 40:737-742

Background and Purpose
Impaired baroreflex sensitivity (BRS) has been previously shown to be of prognostic value in patients with cardiovascular disease and stroke. Because baroreflex seems to be blunted by both carotid atherosclerosis and by lesions affecting central processing, controversy exists regarding the etiology of stroke-related baroreflex changes. The insula may play a central role in baroreflex modulation. The aim of the study was therefore to examine BRS in patients with acute stroke with regard to carotid atherosclerosis and insular involvement.

Methods
We evaluated spontaneous BRS in 96 patients with acute stroke within 72 hours of ictus and 41 control subjects using a sequential crosscorrelation method.

Results
Fifty-two patients with ischemic stroke and 44 patients with intracerebral hemorrhage, mean age 58.4 years, were included. With comparable carotid atherosclerosis profiles, patients with stroke had significantly lower BRS than control subjects (3.3 versus 5.3, P<0.001) Carotid atherosclerosis had no influence on variance of the BRS values in the acute stroke group. Patients with insular involvement had significantly lower BRS than patients with no insular involvement (2.55 versus 4.35, P= 0.001) or control subjects (2.55 versus 5.3, P<0.001) Furthermore, patients with left insular involvement had significantly lower BRS than patients with right insular involvement (2.3 versus 3.5 P=0.0049) There was no significant difference between patients with no insular lesions and control subjects (P=0.263).

Conclusions
We demonstrated that baroreflex impairment in acute stroke is not associated with carotid atherosclerosis but with insular involvement. Both insulae seem to participate in processing the baroreceptor information with the left insula being more dominant.

Comité Editorial: Grupo de Radiológicos TecniScan.

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