Antiarrhythmic effects of losartan and enalapril in canine pulmonary vein sleeve preparations.
J Cardiovasc Electrophysiol
; 22(6): 698-705, 2011 Jun.
Article
en En
| MEDLINE
| ID: mdl-21159010
ABSTRACT
INTRODUCTION:
Angiotensin-converting enzyme (ACE) inhibitors and angiotensin II-receptor blockers (ARBs) are prototypes of "upstream" therapy for the management of atrial fibrillation (AF). Ectopic activity arising from the PV sleeves plays a prominent role in the development of AF.METHODS:
Transmembrane action potentials were recorded from canine superfused left superior or inferior PV sleeves using standard microelectrode techniques. Acetylcholine (ACh, 1 µM), isoproterenol (1 µM), high calcium ([Ca(2+)](o) = 5.4 mM) or a combination was used to induce early or delayed afterdepolarizations (EADs or DADs) and triggered activity.RESULTS:
The ARB losartan (1 µM, n = 5) and the ACE inhibitor enalapril (10 µM, n = 5) produced no significant change in action potential duration, maximum rate of rise of action potential upstroke (V(max)), action potential amplitude or take-off potential at basic cycle lengths of 200 to 2000 ms. Losartan (1 µM) and enalapril (10-20 µM) markedly attenuated or suppressed EADs and DAD-induced triggered activity elicited by exposure of the PV sleeves to ACh, isoproterenol or high calcium following rapid pacing in 6 of 6 (losartan) and 4 of 5 (enalapril) PV sleeve preparations. Neither losartan nor enalapril altered Ca(2+) or K(+) channel currents in enzymatically-dissociated atrial myocytes at these concentrations.CONCLUSIONS:
Our data suggest that in addition to their "upstream" effects to reduce atrial structural remodeling, ACE inhibitors and ARBs exert a "direct" antiarrhythmic effect by suppressing triggers responsible for the genesis of AF and other atrial arrhythmias.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Venas Pulmonares
/
Enalapril
/
Losartán
/
Sistema de Conducción Cardíaco
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Frecuencia Cardíaca
Límite:
Animals
Idioma:
En
Revista:
J Cardiovasc Electrophysiol
Asunto de la revista:
ANGIOLOGIA
/
CARDIOLOGIA
/
FISIOLOGIA
Año:
2011
Tipo del documento:
Article
País de afiliación:
Estados Unidos