Objective:

To compare morphological and functional differences of the heart in two Latin American populations with different ethnicity and living conditions.

Methods:

Using transthoracic echocardiogram we obtained data on 206 individuals: 103 from Atahualpa, Ecuador (living at sea level, mean age: 75 ± 4.2 years, 53 women) and 103 inhabitants from Mexico City (living at 2300 m above sea level, mean age: 75 ± 4.2 years, 52 women).

Results:

Significant differences between Atahualpa and Mexico were: Heart rate 66 versus 80 x’, left ventricular diastolic diameter 40.8 versus 42.7, septum thickness 9.8 versus 11.6, posterior wall 10.2 versus 11.8, stroke volume cc 53.0 versus 46.6, left atrial volume 25. 8 versus 33.6, systolic pressure of the pulmonary artery 27.1 versus 42.0, cardiac output 3.1 versus 4.8, E/Ea ratio 6.4 versus 9.2, and mitral area 3.4 versus 3.0. Comparison of diastolic function between Atahualpa and Mexico was: Type 0; 2 versus 1. Type 1; 96 versus 81. Type 2; 5 versus 20 and Type 3; 0 versus 1.

Conclusion:

Echocardiographic characteristics that identify adaptive changes of the heart in Atahualpa are coincident with people living at sea level and with good physical activity, and Mexico City, with inhabitants living at high altitudes and exposed to environmental pollution. The systolic function of the left ventricle was similar in both populations, indicating that adaptive changes allow the heart to be effective in different circumstances of the ecosystem.