Optical imaging of spiral waves: pharmacological modification of spiral-type excitations in a 2-dimensional layer of ventricular myocardium.
J Electrocardiol
; 38(4 Suppl): 126-30, 2005 Oct.
Article
em En
| MEDLINE
| ID: mdl-16226087
ABSTRACT
Differential effects of sodium channel blockers, an I(Kr) blocker (nifekalant) and amiodarone on the spiral-type reentry, were investigated in rabbit hearts by using a high-resolution optical mapping system. Two-dimensional subepicardial layer of left ventricular myocardium with uniform anisotropy was prepared by endocardial cryoablation. During ventricular tachycardia (VT) elicited by cross-field stimulation, spiral-type excitations rotating around functional block lines (FBLs) were visualized. All the sodium channel blockers stabilized rotors; VT duration was prolonged in association with increases of FBLs and VT cycle length. The rotors in the presence of nifekalant were characterized by large meandering, long FBLs, and frequent front-tail interactions generating wave breaks. Amiodarone (acute application) increased FBLs and VT cycle length, but shortened the VT duration with minimal front-tail interaction. These results suggest that multifaceted drug action on both depolarization and repolarization may be required for the early termination of spiral-type reentry without causing breakup of rotors.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Síndromes de Pré-Excitação
/
Bloqueadores dos Canais de Sódio
/
Sistema de Condução Cardíaco
/
Miocárdio
Limite:
Animals
/
Humans
Idioma:
En
Revista:
J Electrocardiol
Ano de publicação:
2005
Tipo de documento:
Article
País de afiliação:
Japão