Rate pressure product and oxygen saturation in tourists at approximately 3000 m above sea level

Using modern transportation technology, many travelers easily access moderate altitudes of approximately 3000 m above sea level. In the present study the effects of this altitude on cardiovascular parameters were studied among office workers dwelling at sea level.

Heart rate, blood pressure, arterial oxygen saturation (SpO2), and electrocardiography were monitored before and after Master's double-step exercise at 2700 and 3700 m. The test consisted of stepping onto and off of two 23-cm steps for 3 min at a predefined rate.

The resting values recorded for the heart rate and mean blood pressure at 2700 and 3700 m did not statistically significantly differ from those noted at sea level. However, the increases in these values after exercise were significantly greater at high altitude. The rate pressure product more than doubled after exercise at 3700 m. Electrocardiographic abnormalities were observed in some cases. The postexercise blood lactate concentration was significantly higher at 3700 m than at sea level or at 2700 m, suggesting that the oxygen supply-demand relationship was not balanced at this altitude. Furthermore, exercise provoked an acute reduction in SpO2 at 2700 and 3700 m but showed no effect at sea level.

These observations suggest that the oxygenation status of the heart might be at risk in many travelers and workers during and after exercise load at an altitude of approximately 3000 m.