Introduction : The Zipf-Mandelbrot law allowed the development of a methodology that makes quantitative distinctions between acute and normal cardiac dynamics in an objective and reproducible way. Objective : To confirm the diagnostic capacity and clinical utility of the software that automates a methodology based on the Zipf-Mandelbrot law that performs objective diagnoses of the cardiac dynamics. Material and Methods: A blind study was performed with 80 Holter records, 20 normal and 60 with pathological findings. The software organized heart rates in a hierarchical way through their frequencies of occurrence in ranges of 15 beats per min, linearized data, and obtained statistical fractal dimension which allowed the realization of the complexity analysis. Results: The statistical fractal dimension of the normal Holter records was found between 0,720 and 0,913, and exhibited values between 0,454 and 0,665 in the abnormal Holter records. A Kappa coefficient of 1, and specificity and sensitivity values of 100% were found. Conclusions : The clinical utility of the Software that automates the methodology based on the Zipf-Mandelbrot law was confirmed, which allowed to evaluate the behavior of normal and acute cardiac systems. Keywords : Heart rate, fractals, nonlinear dynamics, Electrocardiography Ambulatory, diagnosis.