RESUMO
BACKGROUND: Immune dysfunction has long been proposed as a mechanism for the etiopathogenesis of the chronic phase of Chagas' disease. Antibodies of chagasic patients have been shown to interfere with electric and mechanical activity of embryonic myocardial cells in culture. Here, we demonstrate that antibodies derived from a group of chronic chagasic patients are able to induce disturbances in the electrogenesis and conduction in isolated adult rabbit hearts. METHODS AND RESULTS: Sera from chronic chagasic patients with complex cardiac arrhythmias (ChA+) decreased heart rate (from 131+/-26 to 98+/-37 bpm [mean+/-SD]; n=6; P<.05) in isolated rabbit hearts when perfused at a dilution of 1:100 (vol:vol) by the Langendorff method. Sera from another experimental group of four chronic chagasic patients without complex arrhythmias (ChA-) and two control groups composed of five Wolff-Parkinson-White (WPW) syndrome patients and five orthopedic surgery patients did not affect heart rate when tested under similar conditions. In addition, sera from five of six ChA+ patients and from one WPW patient induced AV conduction blockade. Effects of the sera from ChA+ patients are due to their IgG fractions. Both serum and IgG effects are blocked by atropine (10 micromol/L). CONCLUSIONS: Antibodies of ChA+ patients decrease heart rate and induce AV conduction block in isolated adult rabbit hearts through activation of muscarinic receptors.
Assuntos
Anticorpos Antiprotozoários/imunologia , Cardiomiopatia Dilatada/fisiopatologia , Cardiomiopatia Chagásica/imunologia , Doença de Chagas/imunologia , Bloqueio Cardíaco/fisiopatologia , Síndrome de Wolff-Parkinson-White/fisiopatologia , Adulto , Animais , Nó Atrioventricular/efeitos dos fármacos , Nó Atrioventricular/imunologia , Nó Atrioventricular/fisiopatologia , Atropina/farmacologia , Cardiomiopatia Dilatada/imunologia , Cardiomiopatia Dilatada/parasitologia , Cardiomiopatia Chagásica/fisiopatologia , Doença de Chagas/sangue , Doença Crônica , Eletrocardiografia , Eletrofisiologia , Feminino , Bloqueio Cardíaco/imunologia , Bloqueio Cardíaco/parasitologia , Frequência Cardíaca , Humanos , Imunoglobulina G/farmacologia , Técnicas In Vitro , Masculino , Pessoa de Meia-Idade , Antagonistas Muscarínicos/farmacologia , Coelhos , Síndrome de Wolff-Parkinson-White/imunologia , Síndrome de Wolff-Parkinson-White/parasitologiaAssuntos
Doenças do Sistema Imunitário/complicações , Taquicardia Paroxística/etiologia , Taquicardia Supraventricular/etiologia , Síndrome de Wolff-Parkinson-White/complicações , Adjuvantes Imunológicos/uso terapêutico , Adulto , Suscetibilidade a Doenças , Disopiramida/uso terapêutico , Quimioterapia Combinada , Feminino , Humanos , Doenças do Sistema Imunitário/tratamento farmacológico , Doenças do Sistema Imunitário/imunologia , Masculino , Taquicardia Paroxística/tratamento farmacológico , Taquicardia Paroxística/imunologia , Taquicardia Supraventricular/tratamento farmacológico , Taquicardia Supraventricular/imunologia , Hormônios do Timo/uso terapêutico , Síndrome de Wolff-Parkinson-White/tratamento farmacológico , Síndrome de Wolff-Parkinson-White/imunologiaRESUMO
A study is presented of 32 patients (18 men, 14 women; age from 16 to 38 years) with WPW syndrome. Immunological investigations revealed characteristic of WPW syndrome phenotypic peculiarities with characteristic changes of the immune status, allowed to evaluate the mechanism of formation of Kent's bundle and to discuss the problem of primary prophylaxis by means of immunoactive agents.
