Pioneering studies were performed by Peruvian investigators in healthy natives born and living at high altitudes (HA). Cardiac catheterization was undertaken in newborns, children and adults at 4540 m altitude (Morococha, Peru) and the results were compared with those already described at sea level (SL) [17,52,68]. The mean pulmonary artery pressure (mPAP) in newborns was around 60 mm Hg, a value similar to that described in SL newborns. After birth, the mPAP decreases slowly and persistent PH, of mild or moderate degree, is observed in adolescents and adults, contrasting with the fast decline of mPAP described in the postnatal period at sea level (Figure 1). HA children from 1 to 5 years have an average mPAP of 45 mm Hg, decreasing to 28 mm Hg in adolescents and adults. Table 1 shows the pulmonary hemodynamics in children and adults living at HA.
Histological studies of the distal pulmonary arterial branches were also performed at HA and SL in newborns, children and adults who had died in accidents or from acute non- cardiopulmonary diseases [8,10]. The postnatal changes of the "fetal pattern" differ at SL and HA. At SL the thick medial coat of smooth muscle cells (SMC) suffers a prompt remodeling and consequential thinning of the vessel wall and widening of the lumen. This is in contrast to a delayed maturation at HA, which implies persistence of a
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Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...