Characterization of the cardiovascular autonomic influence through time frequency spectrum analysis

A versatile system for power spectrum analysis using time-dependent techniques have been developed. The authors describe the capability of the Wigner-Ville (WV) time-frequency distribution to achieve a beat-to-beat characterization of the time course of the autonomic control of heart rate variability during the administration of autonomic tests in normal subjects and in patients with cardiac Chagas' disease. To evaluate the method, different autonomic tests have been selected on the basis of the well-known behavior of the vagal-sympathetic balance, undergoing transient, sudden changes of very short duration. The WV distribution permitted achievement of full characterization of the beat-to-beat evolution.<
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