RESUMO
A consecutive series of 66 patients (males = 32; mean age +/- SD = 71 +/- 9 years) given atrial inhibited pacemakers for sick sinus nodes were followed to study the incidence of lead failures, chronic atrial tachyarrhythmias, and atrioventricular conduction disturbances. The need for rate responsive pacing was also assessed. Pre and postoperative investigation could include carotid sinus massage, Holter monitoring, exercise testing, and invasive electrophysiology. The mean follow-up time +/- SD was 32 +/- 29 months (median = 26 months). Three patients (5%) had their pacemakers replaced due to lead failures (loss of sensing = 2; exit block = 1). Two pacemakers (3%) were replaced after 5 and 22 months due to atrial fibrillation. Four patients (6%) received new pacemakers because of development of second-degree or complete atrioventricular block after 1, 6, 12, and 31 months, respectively. During exercise, most patients (76%) responded with an increase in sinus rate at least as marked as that achievable with the currently available rate responsive pacemakers. Assuming careful patient selection, atrial inhibited pacing is well suited for many patients with sinus node dysfunction and preserved atrioventricular conduction. There is a limited need for rate responsive pacemakers in these patients.
Assuntos
Nó Atrioventricular/fisiopatologia , Estimulação Cardíaca Artificial/métodos , Sistema de Condução Cardíaco/fisiopatologia , Marca-Passo Artificial , Síndrome do Nó Sinusal/terapia , Idoso , Idoso de 80 Anos ou mais , Eletrocardiografia , Teste de Esforço , Feminino , Seguimentos , Frequência Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Monitorização Fisiológica , Fatores de TempoRESUMO
The efficacy and safety of flecainide for long-term prevention of paroxysmal atrial fibrillation (AF) were studied in an open trial. Twenty patients with very frequent attacks (mean 13 per month) of paroxysmal AF for many years (mean 8 years) participated. Before inclusion, the patients had unsuccessfully been treated with an average of 3.3 antiarrhythmic drugs. Efficacy was jugded from a carefully kept diary in which the patients made daily notes of any AF attacks and possible side-effects from 1 month before treatment until the end of a follow-up period of 6 months. Twelve patients (60%) were completely free from AF and 11 of these are still successfully treated with flecainide after 11-38 months (mean 24 months). Flecainide plasma levels did not differ between responders and non-responders. Eleven patients (55%) had adverse effects but these were usually mild and well tolerated, necessitating withdrawal or dose reduction resulting in relapse of AF only in three patients (15%). No proarrhythmic events were seen.