Il paziente affetto da insufficienza cardiaca cronica. Esercizio fisico e allenamento contro resistenza

Specific strength training is accepted as a means for improving and preserving skeletal muscle (SM) strength, power and mass, and more recently the efficiency of cardiovascular status. This turns out to be very important in cardiovascular diseases and in particular in chronic heart failure (CHF). The aim of the present study was to test whether the appropriately prescribed and carefully supervised strength training program, was able to generate cardiovascular benefit by heart and metabolic improvements in CHF patients. For this reason 12 CHF patients (all males, 66.7 ±5.4yy, 74.9±14.1kg, 173.5±5.9cm, NYHA-class II, ICD implanted) performed on Sports Science Faculty 16 weeks of controlled and progressive strength training for 1:30 hour, 3 times/week. Every session was based on 70% of 1RM performed on 6 isotonic equipments (3 for legs, 3 for arms) and started with joint and muscle warm up and ended with cool down and stretching exercises. SM strength, metabolic, and cardiovascular indexes were tested before and after the training. After the training, the overall maximal force increased from 128.9Kg to 192.8Kg (51.5%) and from 273 to 405kg (47%) for arms and legs, respectively. The total DXA free fatty mass FFM didn’t change although showed a significant increase (P<0,01) by 2% on legs only. The VO2peak significantly increased from 18.1 to 20.6 ml*kg-1*min-1 (P<0.001) and the oxygen intake at ventilatory threshold (VO2vt) increased by 20.8%(P<0.002). The echocardiographically evaluated ejection fraction (EF) at rest changed from 32.3 to 35.2% (P=0.04). The results show that strength training specifically improves health-related indexes (VO2peak, VO2vt and SM strength) as well as clinical cardiovascular parameters (EF) without cardiac dilatation (EDV was significantly reduced by 5%) on CHF subjects. If the enhancement in SM strength is a specific outcome of strength training, metabolic and cardiovascular improvements should rather be induced by aerobic training. A slight increase in FFT was seen on legs only. We believe that the training period was too short to improve also arm FFM. The novel feature of this study is the demonstration that heart function in CHF takes advantage by a training program specifically suitable to prevent SM atrophy. Specific cardiac index like EF and EDV also rappresent an important outcome in this population. None of the subjects quit the project in advance, while several asked to continue beyond its end; therefore the study also proved the feasibility of training in an extra-hospital setting.