Artículo de revista
Effects of carvedilol on oxidative stress and chronotropic response to exercise in patients with chronic heart failure
Fecha
2005-10Registro en:
EUROPEAN JOURNAL OF HEART FAILURE 7 (6): 1033-1039 OCT 2005
1388-9842
Autor
Castro, Pablo
Mc-Nab, Pablo
Quintana, Juan Carlos
Bittner, Alex
Greig, Douglas
Vergara, Ismael
Vukasovic Ramírez, José Luis
Corbalán, Ramón
Copaja, Miguel
Díaz Araya, Guillermo
Chiong Lay, Mario
Troncoso Cotal, Rodrigo
Alcaíno Gálvez, Hernán Alejandro
Lavandero González, Sergio
Institución
Resumen
Background: Our previous studies suggest that the increase in heart rate from rest to peak exercise is reduced in patients with chronic heart failure (CHF) and this is associated with increased oxidative stress, as determined by malondialdehyde (MDA) plasma levels.
Aim: To investigate the effects of carvedilol on the heart rate response to exercise and oxidative stress in patients with CHF.
Methods and results: Thirty stable NYHA classes II-III CHF patients received carvedilol therapy for 6 months, at a mean maintenance dose of 25 mg (range 6.25-50 mg/day). After treatment, the patients showed a significant improvement in their functional NYHA class (p=0.013), increased tell ventricular ejection fraction (LVEF) (24 +/- 1.4% to 31 +/- 2.3%, p=0.003) and 6-min walk distance (499 +/- 18 to 534 +/- 18 m, p=0.03), without changes in the peak VO2. At baseline, norepinephrine (NE) plasma levels increased with exercise (510 +/- 51 to 2513 +/- 230 pg/mL, p < 0.001), and these levels were not affected by carvedilol. Chronotropic responsiveness index (increase in heart rate divided by the increase in NE from rest to peak exercise) was not changed by carvedilol (0.049 +/- 0.001 to 0.042 +/- 0.001, p=0.6). MDA levels of CHF patients decreased after treatment with carvedilol (2.4 +/- 0.2 to 1.1 +/- 0.2 mu M p < 0.001), without changes in antioxidant enzyme activities.
Conclusions: Carvedilol treatment in patients with CHF results in reduced oxidative stress Without restoration of the chronotropic responsiveness index.