The study hypothesizes that an assumed cardiovascular performance reserve is physiologically detectable.

High reserve at rest characterizes a healthy person while low reserve at rest characterizes low functional capacity e.g. heart failure. The lower the reserve the severer the morbidity.

The reserve may be estimated through CVRI (cardiovascular reserve index) which is computed by an algorithm composed of physiological measurements taken during the patient visit.

In this study the investigators evaluate CVRI capability in prediction of functional capacity in comparison with the clinical evaluation during the same visit.

The study hypothesizes that an assumed cardiovascular performance reserve is physiologically detectable and continuously monitored by a physiological control (reserve control)not yet discovered.

High reserve at rest characterizes a healthy person while low reserve at rest characterizes low functional capacity e.g. heart failure. The lower the reserve the severer the morbidity.

The reserve is decreased reversibly with aerobic activity and may reach an exhaustion threshold in which the assumed reserve control induces a reversible fatigue and dyspnea which dissolve once the activity decreased.

The reserve may be estimated through CVRI (cardiovascular reserve index) which is computed by an algorithm composed of physiological measurements taken during the patient visit (composed of blood pressure, heart rate, respiratory rate, central venous pressure or its estimation, weight, height and gender.

In this study the investigators evaluate CVRI capability in prediction of functional capacity in comparison with the clinical evaluation during the same visit (cross sectional comparison).

Inclusion Criteria:

• adult informed consent

Exclusion Criteria:

• an emergency case

The study population is composed of adults both genders:

healthy subjects visiting for administrative cause healthy subject during acute illness patients with chronic conditions