RESUMEN
In this work we studied the incidence and characteristics of early postinfarction arrhythmias in rabbits with sympathetic denervation. The electrical and haemodynamic changes were analyzed. Three groups of animals submitted to coronary occlusion were studied. A control group of normal animals (I), another group of animals injected with practolol prior to occlusion (5 mg/kg i.v.) (II) and a third group of animals in which stellate ganglia were surgically excised prior to occlusion (III). In the control group incidence of early postinfarction arrhythmias was 60% (12 of 20) while in Groups II and III incidence was only 25% (3 of 12 rabbits). The influence of excision or pharmacological blockade of sympathetic system and their role in the genesis of the early arrhythmias is discussed.
Asunto(s)
Arritmias Cardíacas/etiología , Infarto del Miocardio/complicaciones , Sistema Nervioso Simpático/fisiopatología , Animales , Arritmias Cardíacas/fisiopatología , Arritmias Cardíacas/prevención & control , Presión Sanguínea/efectos de los fármacos , Femenino , Ganglios Simpáticos/fisiopatología , Frecuencia Cardíaca/efectos de los fármacos , Masculino , Infarto del Miocardio/tratamiento farmacológico , Infarto del Miocardio/fisiopatología , Practolol/farmacología , Conejos , Receptores Adrenérgicos beta/efectos de los fármacos , Receptores Adrenérgicos beta/fisiología , SimpatectomíaRESUMEN
In order to evaluate the influence of the autonomic nervous system in the incidence and characteristics of the early arrhytmias that follows myocardial infarction, we have developed an experimental myocardial infarction in rabbits by acute occlusion of the left ventricular artery. The influence of adrenergic and cholinergic suppression over rhythm disorders and hemodynamics changes after experimental infarction in the rabbit was also studied. We found that after the acute experimental infarction in the rabbit heart, arose an early stage of rhythm disorders in 60% of the animals. In a group of animals that were injected with Practolol before coronary occlusion, the incidence of arrhythmias was 25% and in a group of animals with vagotomy prior to occlussion none of them developed rhythm disorders. It was concluded that the model is highly steemed for the study of early arrhytmias and that automatic nervous system has an important role in the incidence of such arrhythmias.