Inducibility of Ventricular Arrhythmia 1 Year Following Treatment with Heavy Ion Irradiation in Dogs with Myocardial Infarction.
Pacing Clin Electrophysiol
; 40(4): 379-390, 2017 Apr.
Article
em En
| MEDLINE
| ID: mdl-28158934
ABSTRACT
BACKGROUND:
Targeted external heavy ion irradiation (THIR) of rabbit hearts 2 weeks after myocardial infarction (MI) reduced the vulnerability of fatal ventricular tachyarrhythmias (VT/VF) in association with the increased connexin43 (Cx43). Increased Cx43 was maintained for at least 1 year in normal rabbits, but the long-term antiarrhythmic effects in the MI model are unknown. We investigated the propensity for late potentials and VT/VF inducibility.METHODS:
Intracoronary injection of microspheres was performed to induce nontransmural MI in anesthetized eight beagles. Four beagles were treated with THIR (12 C6+ , 15 Gy) 2 weeks later (MI + THIR group), and four without THIR served as controls (MI group). Signal-averaged electrocardiography, programmed electrical stimulation, immunohistochemical analysis, and echocardiograms were performed at 1 year.RESULTS:
Filtered QRS duration was exacerbated after MI and remained unchanged for 1 year in the MI group (118 ± 1.4 ms), but significantly returned toward baseline in the MI + THIR group (109 ± 6.9 ms). Similarly, root mean square voltage of the last 40 ms was exacerbated after MI, but recovered after THIR. VT/VF inducibility decreased to 25% in the MI + THIR group compared with 100% in the MI group. Immunostaining Cx43 expression in cardiac tissues significantly increased by 24-45% in the MI + THIR group. Left ventricular ejection fractions remained within the normal range in both groups.CONCLUSION:
A single exposure of the dog heart to 12 C irradiation attenuated vulnerability to ventricular arrhythmia after the induction of MI for at least 1 year through the modulation of Cx43 expression.Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Fibrilação Ventricular
/
Taquicardia Ventricular
/
Radioterapia com Íons Pesados
/
Infarto do Miocárdio
Idioma:
En
Ano de publicação:
2017
Tipo de documento:
Article