Effects of interval exercise training on respiratory drive in patients with chronic heart failure.
BACKGROUND
Patients with chronic heart failure (CHF) suffer from ventilatory abnormalities. This study examined the effects of interval exercise training on the respiratory drive in CHF patients.


METHODS
Forty-six clinically stable CHF patients (38 males/8 women, mean age = 53 +/- 11 years) participated in an exercise rehabilitation program (ERP) 3 times/week, for 12 weeks by interval training modality with or without the addition of resistance training. All patients underwent symptom-limited cardiopulmonary exercise testing (CPET), and measurements of mouth occlusion pressure at 100 ms (P(0.1)) and maximum inspiratory muscle strength (P(Imax)) before and after ERP. Respiratory drive was estimated by mouth occlusion pressure P(0.1) and P(0.1)/P(Imax) ratio at rest, and the ventilatory pattern by resting mean inspiratory flow (V(T)/T(I)) and by V(T)/T(I) at identical CPET workloads, before and after ERP. We also studied a control non exercising group of 11 patients (8 men and 3 women).


RESULTS
P(0.1) at rest decreased from 3.04 +/- 1.52 to 2.62 +/- 0.9 cmH(2)O (p = 0.015), P(0.1)/P(Imax) % at rest from 4.56 +/- 3.73 to 3.69 +/- 2.03 (p = 0.006), resting V(T)/T(I) from 0.44 +/- 0.10 to 0.41 +/- 0.10 l/s (p = 0.014), and V(T)/T(I) at identical work rate from 2.13 +/- 0.59 to 1.93 +/- 0.58 l/s (p = 0.001) after ERP. VO(2) at peak exercise increased from 16.3 +/- 4.8 to 18.5 +/- 5.3 ml/kg/min (p < 0.001) in the exercise group. No improvement was noted in the control group.


CONCLUSIONS
ERP by interval training improves the respiratory drive and ventilatory pattern at rest and during exercise in CHF patients.
Tasoulis
Athanasios
A
Pulmonary & Critical Care Medicine Department, Cardiopulmonary Exercise Testing and Rehabilitation Laboratory, Evgenidio Hospital, National & Kapodistrian University of Athens, Papadiamantopoulou St, Athens, Greece.
Papazachou
Ourania
O
Dimopoulos
Stavros
S
Gerovasili
Vasiliki
V
Karatzanos
Eleftherios
E
Kyprianou
Theodoros
T
Drakos
Stavros
S
Anastasiou-Nana
Maria
M
Roussos
Charis
C
Nanas
Serafim
S
D015308:Anaerobic Threshold / Q000502:physiology*; D002908:Chronic Disease; D004417:Dyspnea / Q000503:physiopathology* / Q000534:rehabilitation; D005081:Exercise Therapy; D005260:Female; D006333:Heart Failure / Q000503:physiopathology* / Q000534:rehabilitation; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology*; D011788:Quality of Life; D016896:Treatment Outcome