Effects of carvedilol on cardiac autonomic nerve activities during sinus rhythm and atrial fibrillation in ambulatory dogs.
Europace
; 16(7): 1083-91, 2014 Jul.
Article
em En
| MEDLINE
| ID: mdl-24469435
ABSTRACT
AIMS:
We hypothesized that carvedilol can effectively suppress autonomic nerve activity (ANA) in ambulatory dogs during sinus rhythm and atrial fibrillation (AF), and that carvedilol withdrawal can lead to rebound elevation of ANA. Carvedilol is known to block pre-junctional ß2-adrenoceptor responsible for norepinephrine release. METHODS ANDRESULTS:
We implanted radiotransmitters to record stellate ganglion nerve activity (SGNA), vagal nerve activity (VNA), and superior left ganglionated plexi nerve activity (SLGPNA) in 12 ambulatory dogs. Carvedilol (12.5 mg orally twice a day) was given for 7 days during sinus rhythm (n = 8). Four of the eight dogs and an additional four dogs were paced into persistent AF. Carvedilol reduced heart rate [from 103 b.p.m. (95% confidence interval (CI), 100-105) to 100 b.p.m. (95% CI, 98-102), P = 0.044], suppressed integrated nerve activities (Int-NAs, SGNA by 17%, VNA by 19%, and SLGPNA by 12%; all P < 0.05 vs. the baseline), and significantly reduced the incidence (from 8 ± 6 to 3 ± 3 episodes/day, P < 0.05) and total duration (from 68 ± 64 to 16 ± 21 s/day, P < 0.05) of paroxysmal atrial tachycardia (PAT). Following the development of persistent AF, carvedilol loading was associated with AF termination in three dogs. In the remaining five dogs, Int-NAs were not significantly suppressed by carvedilol, but SGNA significantly increased by 16% after carvedilol withdrawal (P < 0.001).CONCLUSION:
Carvedilol suppresses ANA and PAT in ambulatory dogs during sinus rhythm.Palavras-chave
Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Propanolaminas
/
Fibrilação Atrial
/
Sistema Nervoso Autônomo
/
Carbazóis
/
Antagonistas de Receptores Adrenérgicos alfa 2
/
Antiarrítmicos
Tipo de estudo:
Diagnostic_studies
/
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Europace
Assunto da revista:
CARDIOLOGIA
/
FISIOLOGIA
Ano de publicação:
2014
Tipo de documento:
Article