Acta Andina     2001; 9 (1-2) : 63

 

HIGH ALTITUDE PHYSIOLOGY. CARDIAC AND RESPIRATORY ASPECTS A CIBA FOUNDATION SYMPOSIUM IN HONOUR OF PROFESOR
ALBERTO HURTADO LONDRES, 1971

 

SUMMARY AND CONCLUSIONS


Anatorny of the coronary circulation at high altítude.

ARIAS- STELLA J Y TOPILSKY M. (1)

Using the method of preparing casts of the coronary arterial system through aortic injection of rapid1y polymerising acrylic resin at a pressure of 150-200 mmHg, followed by fixation and corrosion, a different patterrí has been found in the vascularization of individuals from Cerro de Pasco (4375 m) from that seen in subjects from sea level. These results are compared with those recently obtained in our laboratory by Dr. Carmelino in subjects from Puno (3466-4287 m), using the post?mortem stereoangiographic method. Both studies show that the number of branches leaving the main coronary trunks is greater and the peripheral ramifications are more numerous at high altitudes. The physiological and clinical significance of these findings is discussed.

Coronary blood flow and rnyocardial metabolism in man at high altitude

MORET PR (2)

Coronary blood flow and rnyocardial metabolism were studied in normal subjects living in Perú and Bolivia at three different altitudes: Lima (150 m), La Paz (3700 m) and Cerro de Pasco (4375 m). Coronary blood flow is lower at high altitude, as is the oxygen consumption of the rnyocardium, with the result that rnyocardial efficiency is greater. The lower coronary flow at high altitude is not compensated

for by any increased oxygen transport capacity of the blood. Substrates usually extracted by the heart -glucose, lactate, pyruvate and free fatty acids- are the same at high and low altitude, but at high altitude the heart consumes more carbohydrates, especially lactate, and there are no signs of anaerobic metabolism. The lower coronary blood flow and oxygen consumption and absence of signs of anaerobic metabolism at high altitude suggest an adaptation of cellular metabolism to low oxygen pressure. Six patients with chronic mountain sickness were also studied. Coronary blood flow was higher than in the normal groups, and in some cases the rnyocardium seems to be slight1y underperfused. The percentage oxygen extraction is increased, in contrast to the normal subjects, and the extraction of metabolites also differs.

Sorne observations on the blochemistry of the myocardium at high altitude

HARRIS P (3)

Measurements of succinic dehydrogenase and lactic dehydrogenase activity have been made on rnyocardial homogenates from guinea pigs, rabbits and dogs indigenous to high altitude and compared with measurements made on the same species at sea level. A consistent increase in the activity of succinic dehydrogenase was found in the high altitude animals but no significant difference in lactic dehydrogenase.

Analyses of the lipid content of the rnyocardium have shown that there is a consistent increase in total lipid, total phospholipid, cholesterol and sphingornyc1in in the rnyocardium of the three species of animal at high altitude.

UTILIZACIÓN DE LA ALTURA NATURAL Y SIMULADA EN REHABILITACIÓN CARDIACA CORONARIA

En 1971, tres de los participantes en el Sympositim Ciba de Fisiología de Altura en 1971 - en Londres - Inglaterra, en honor del Profesor Alberto Hurtado; expusieron respectivamente -sus observaciones en: 1) La profusa vasculatura coronaria en individuos de la altura (A) respecto de especímenes de nivel del mar (NM) 1, 2) Menor flujo coronario con mayor eficiencia miocárdica en el nativo de A2 y 3) Mayor actividad enzimática del miocardio 1 dehydrogenasa succinica, en animales menores de A 1. Estos tres enfoques por investigadores separados, orientados a la exploración del miocardio de A y de NM, han contribuido al desarrollo de los procedimientos que actualmente utilizan hipoxia natural (Andes) y Altura Simulada (Cámara Hipobárica) con fines - específicos- de Rehabilitación Cardiaca Coronaria (RCC). En este sentido, es Perú -en el mundo- que desplaza por primera vez a la A (5000 m) pacientes coronarios con y sin infarto de miocardio con fines de RCC4.

Retornando a la modalidad de A Simulada (CH), se reporta por Perú en 1994 1. Ese mismo año, se menciona la primera experiencia soviética 1. Actualmente en el Perú se profundizan los mecanismos que pretenden explicar cómo actuaría la H rehabilitando al miocardio, considerando que probablemente es al nivel de la biología molecular donde tales mecanismos tendrían lugar7-8.

Finalmente, es un privilegio para el comentarista de estas líneas de investigación, haberse ocupado ajustadamente sobre la trascendencia que significa la contribución de los investigadores: Arias Stella, Moret y Harris en el manejo actual de la RCC con hipoxia, en el Perú y fuera de él.


Dr. Emilio A. Marticorena

Profesor Emérito de Medicina, UNMSM
Docente Investigador
Fuerza Aérea del Perú   Hosp. Las Palmas



Bibliografía


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