Biomedical subjects

Piergiuseppe Agostoni

Publications and source records attributed to Piergiuseppe Agostoni.

20 records · Page 2Linked to original sources

PubMed2002

Carvedilol reduces the inappropriate increase of ventilation during exercise in heart failure patients.

STUDY OBJECTIVE: To evaluate the effects of beta-blockers on ventilation in heart failure patients. Indeed, beta-blockers ameliorate the clinical condition and cardiac function of heart failure patients, but not exercise capacity. Because ventilation is inappropriately elevated in heart failure patients due to overactive reflexes from ergoreceptors and chemoreceptors, we hypothesized that beta-blockers can elicit their positive clinical effects through a reduction of ventilation. DESIGN: This was a double-blind, randomized, placebo-controlled study. SETTING: University hospital heart failure unit. PATIENTS AND INTERVENTIONS: While receiving placebo (2 months) and a full dosage of carvedilol (4 months), 15 chronic heart failure patients were evaluated by quality-of-life questionnaire, pulmonary function tests, cardiopulmonary exercise tests with constant workload, and a ramp protocol. RESULTS: Therapy with carvedilol did not affect resting pulmonary function and exercise capacity. However, carvedilol improved the results of the quality-of-life questionnaire, reduced the mean (+/- SD) slope of the minute ventilation (E)/carbon dioxide output (CO(2)) ratio (from 36.4 +/- 8.9 to 31.7 +/- 3.8; p < 0.01) and reduced ventilation at the following times: at peak exercise (from 60 +/- 14 to 48 +/- 15 L/min; p < 0.05); during the intermediate phases of a ramp-protocol exercise; and during the steady-state phase of a constant-workload exercise (from 42 +/- 14 to 34 +/- 13 L/min; p < 0.05, at third min). The end-expiratory pressure for carbon dioxide increased as ventilation decreased. The reduction in the E/CO(2) ratio was correlated with improvement in quality of life (r = 0.603; p < 0.02). CONCLUSIONS: Improvement in the clinical conditions of heart failure patients treated with carvedilol is associated with reductions in the inappropriately elevated ventilation levels observed during exercise.

Adrenergic beta-Antagonists↗

PubMed2002

Pulmonary hemodynamic and tidal volume changes during exercise in heart failure.

BACKGROUND: Impairment of lung mechanics, increase of pulmonary artery pressure and limitation of exercise capacity are common findings in chronic heart failure. The objective of the present study was to evaluate whether pulmonary mechanics are correlated with pulmonary hemodynamics, whether both are correlated with the functional capacity and whether the time course of their changes during exercise correlates with the exercise capacity. METHODS: We performed a cardiopulmonary exercise test (breath by breath analysis of ventilation and gas exchange, cycloergometer, 25 W increments every 3 min) with pulmonary hemodynamic monitoring in 38 heart failure patients. The parameters were analyzed at rest, 1 min after the work rate increase and at peak exercise. RESULTS: A significant linear correlation with peak oxygen consumption was found at rest for: mean pulmonary artery pressure (mPAP, r = -0.56), right atrial pressure (RAP, r = -0.42), pulmonary wedge pressure (PWP, r = -0.53), and total pulmonary (TPR, r = -0.53) and pulmonary vascular resistances (PVR, r = -0.45); after 1 min of exercise for: cardiac index (CI, r = 0.49), mPAP (r = -0.57), RAP (r = -0.60), PWP (r = -0.45), and TPR (r = -0.67) and PVR (r = -0.38); at peak exercise for: tidal volume (r = 0.63), CI (r = 0.63), RAP (r = -0.43), TPR (r = -0.65) and PVR (r = -0.43). A significant linear correlation with peak oxygen consumption was found, for the increment between rest and 1 min of exercise, for RAP (r = -0.58) and CI (r = 0.42) and, for the increments between rest and peak exercise, for tidal volume (r = 0.79) and CI (r = 0.61) and, for the ratio between the increment between rest and 1 min of exercise/increment between rest and peak exercise, for mPAP (r = -0.42), RAP (r = 0.51) and CI (r = -0.54). The same ratio of increment of mPAP (r = 0.39) and CI (r = 0.36) correlated with that of tidal volume. CONCLUSIONS: This study provides evidence of a strong correlation between the respiratory function and pulmonary vascular pressure changes during exercise in heart failure.

Adult↗