RESUMO
The M-Mode echocardiographic measurements, according to the international criteria, were done in tracings of 274 normal subjects residents of Mexico City, in order to know the normal values in its population. One hundred and thirty one males (47.8%), and 143 females (52.2%). The age varied from 1 to 73 years, the predominant group was between the third and fifth decades of the life. The age, weight and body surface area (BSA) were correlated with measurements, better correlation was found with BSA and it was the analysis base. According to the BSA, 6 subgroups were formed, the first one of 0.5 m2; increasing 0.4 m2 for each subgroup until the last one of 2.1(2) or more. Were observed proportional amount respect to BSA of D-E mitral valve excursion, aortic root diameter, aortic excursion, aortic opening amplitude, left atrium diameter, end diastolic and end systolic diameters of left ventricle, as well as interventricular septum (IVS) and posterior wall (PW) thickness. The measures were less than the reported other countries. The mean velocity of circumferential shortening (Vcf), fractional shortening (FS) and normalized velocities (NV) showed inverse proportion to BSA. The values of Vcf and NV were similar to the previous report, but the FS and the ejection fraction were higher. The study let us to know the normal echocardiographic values for people of Mexico and the differences with respect to the altitude of this city and the body frame of its population.