We tested the diagnostic contribution of parameters describing the relationship between heart rate (HR) and systolic blood pressure (SBP) on patients with cardioverterdefibrilator (ICD), patients with coronary heart disease and young and old healthy. The best diagnostic of ICD group (p<0.01) is at baroreflex sensitivity and phase variability between HR and SBP in low frequency band, if the controlled breathing 0.1 Hz is used. Both parameters are independent and should be used simultaneousl