Impedimento dell'innervazione autonoma nei pazienti con insufficienza cardiaca avanzata rivelato dalla variabilità del ritmo cardiaco non lineare misurata durante l'esercizio.

Advanced heart failure is characterized by profound autonomic dysfunction, yet resting measures of heart rate variability (HRV) provide limited insight into autonomic adaptability under physiological stress. We investigated whether graded exercise unmasks alterations in cardiac autonomic regulation in patients with advanced heart failure using both conventional and information-theoretic HRV measures. 77 patients with end-stage heart failure with reduced ejection fraction underwent resting and cycle-ergometer exercise testing with continuous electrocardiographic recording. HRV was assessed at rest, during early exercise and at peak exercise using time- and frequency-domain indices alongside e