title: Effects of short-term carvedilol on the cardiac sympathetic activity assessed by 123I-MIBG scintigraphy.
abstract: BACKGROUND
  Autonomic alterations in heart failure are associated with an increase in morbimortality. Several noninvasive methods have been employed to evaluate the sympathetic function, including the Meta-Iodobenzylguanidine (123I-MIBG) scintigraphy imaging of the heart.
  
  
  OBJECTIVE
  to evaluate the cardiac sympathetic activity through 123I-MIBG scintigraphy, before and after three months of carvedilol therapy in patients with heart failure and left ventricular ejection fraction (LVEF) < 45%.
  
  
  METHODS
  Sixteen patients, aged 56.3 +/- 12.6 years (11 males), with a mean LVEF of 28% +/- 8% and no previous use of beta-blockers were recruited for the study. Images of the heart innervation were acquired with 123I-MIBG, and the serum levels of catecholamines (epinephrine, dopamine and norepinephrine) were measured; the radioisotope ventriculography (RIV) was performed before and after a three-month therapy with carvedilol.
  
  
  RESULTS
  Patients' functional class showed improvement: before the treatment, 50% of the patients were FC II and 50% were FC III. After 3 months, 7 patients were FC I (43.8%) and 9 were FC II (56.2%), (p = 0.0001). The mean LVEF assessed by RIV increased from 29% to 33% (p = 0.017). There was no significant variation in cardiac adrenergic activity assessed by 123I-MIBG (early and late resting images and washout rate). No significant variation was observed regarding the measurement of catecholamines.
  
  
  CONCLUSIONS
  The short-term treatment with carvedilol promoted the clinical and LVEF improvement. However, this was not associated to an improvement in the cardiac adrenergic activity, assessed by 123I-MIBG scintigraphy, as well as the measurement of circulating catecholamines.
authors: Universidade Federal Fluminense, Niterói, RJ, Brazil. sandramarina@cardiol.br
authors: Sandra Marina Ribeiro de
authors: SM
authors: Miranda
authors: Evandro Tinoco
authors: ET
authors: Mesquita
authors: Hans Fernando da Rocha
authors: HF
authors: Dohmann
authors: Jader Cunha
authors: JC
authors: Azevedo
authors: Gustavo Borges
authors: GB
authors: Barbirato
authors: Fabiano de Lima
authors: Fde L
authors: Freire
authors: Mário Luiz
authors: ML
authors: Ribeiro
authors: Antonio Cláudio Lucas da
authors: AC
authors: Nóbrega
authors: Alexandro
authors: A
authors: Coimbra
authors: Cláudio Tinoco
authors: CT
authors: Mesquita
mesh_terms: D019797:3-Iodobenzylguanidine; D000320:Adrenergic Fibers / Q000187:drug effects; D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000328:Adult; D000368:Aged; D002227:Carbazoles / Q000627:therapeutic use*; D000077261:Carvedilol; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000294:innervation / Q000503:physiopathology; D054143:Heart Failure, Systolic / Q000000981:diagnostic imaging / Q000188:drug therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011412:Propanolamines / Q000627:therapeutic use*; D011446:Prospective Studies; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D013318:Stroke Volume / Q000187:drug effects; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000319:Adrenergic beta-Antagonists; D002227:Carbazoles; D011412:Propanolamines; D019275:Radiopharmaceuticals; D000077261:Carvedilol; D019797:3-Iodobenzylguanidine