COMPORTAMENTO DURANTE SFORZO DI ALCUNI PARAMETRI CARDIOCIRCOLATORI. VALORI DI RIFERIMENTO PER SOGGETTI NORMALI

The increasing employment of exercise tests for diagnosis in heart patients and to assess the cardiovascular response to effort in healthy subjects has underscored the need for reference values for the normal population, covering the intermediate steps of an ergospirometric test as well as the maximum values. A study for this purpose was therefore run on 226 healthy male volunteers aged 20-75 yr with no history of diseases directly or indirectly capable of involving the cardiovascular apparatus, and a normal objective and instrumental cardiovascular picture (51 aged 20-29; 52 aged 30-39; 52 aged 40-59; 71 aged 50-75). The bicycle test was conducted in the erect position with by W workload increases every 3 min. The following parameters were evaluated at each step for each age class: oxygen uptake (VO₂) heart rate (HR), systolic pressure (BPs), double product (BP x HP), diastolic pressure (BPd), VO₂/kg, oxygen pulse (PO₂) and ventilation/min (VE). The following maximum values were also considered: maximal work capacity (MWC) in watts, total work (TW) in kgm, functional capacity index (FCI), HR, BPs, PB x HP, VO₂ and VO₂/kg. The statistical analysis comprised two states: assessment of the distributions with respect to age, using analysis of variance, determination of the correlation coefficients associated with the spread diagrams for each variable and the respective significance values, and the linearity test (VO₂ only was not significant in the test for correlation and linearity with respect to age, and its overall distribution for all age was considered); shifts from the normal of each distribution, using the skewness and kurtosis indices. All the variables were normally distributed or normalizable by logarithmic transformation. The means, standard deviations and 5% confidence limits (using a non-parametric method for VO₂) were computed for each distribution identified in this way.