Mailing Address: Marcos Antonio Almeida Santos • Avenida Gonçalo Prado Rollemberg, 211, sala 210, São José. Postal Code 49010‐410, Aracaju, SE – Brazil. E‐mail: [email protected]; [email protected] Manuscript received October 09, 2014; revised manuscript November 13, 2014; accepted November 13, 2014.

Heart-rate variability (HRV) is frequently introduced as mirroring imbalances within the autonomous nerve system. Many investigations are based on the paradigm that increased sympathetic tone is associated with decreased parasympathetic tone and vice versa. But HRV is probably more than an indicator for probable disturbances in the autonomous system. Some perturbations trigger not reciprocal, b...