RESUMEN
ß-Blockers are an essential component of medical therapy in patients with ischemic heart disease or cardiac dysfunction of any genesis. They have an effect at the level of the sinus and the atrioventricular node, as well as on the atrial and ventricular refractory period of the myocardium. Overall, there are complicated antifibrillatory effects which are involved in the reduction of morbidity and mortality of this the therapy. According to the guidelines, it is important to uptitrate to highest tolerated dose. In patients with atrial fibrillation, antiadrenergic therapy should be the first line treatment; if well tolerated, then ß-blockers alone or as a combination with an antiarrhythmic drug is preferable. Future prospective studies on the antiarrhythmic effects in this therapeutic area should include comparisons of different α - and ß-selective active substances. Increasing knowledge of the differential therapy with the available active substances including intravenously applicable short-acting ß-blockers, e.g., in intensive care therapy - should distinguish the different therapeutic effects.
Asunto(s)
Fibrilación Atrial/tratamiento farmacológico , Antagonistas Adrenérgicos beta/efectos adversos , Antagonistas Adrenérgicos beta/uso terapéutico , Fibrilación Atrial/mortalidad , Ensayos Clínicos como Asunto , Enfermedad Coronaria/tratamiento farmacológico , Enfermedad Coronaria/mortalidad , Desfibriladores Implantables , Relación Dosis-Respuesta a Droga , Electrocardiografía/efectos de los fármacos , Insuficiencia Cardíaca/tratamiento farmacológico , Insuficiencia Cardíaca/mortalidad , Humanos , Infusiones Intravenosas , Isquemia Miocárdica/tratamiento farmacológico , Isquemia Miocárdica/mortalidad , Guías de Práctica Clínica como Asunto , Tasa de SupervivenciaRESUMEN
This review summarizes the current status of pharmacological therapy for ventricular arrhythmias in symptomatic patients. The selection of specific drugs for this indication is highly dependent on the underlying heart disease. In primary prevention of sudden death, antiarrhythmic agents do not play a role--except betareceptor antagonists. Similarly, in patients treated for secondary prevention of cardiac arrest or hemodynamically symptomatic ventricular tachycardia, the implantable defibrillator constitutes the therapy of choice with hardly any role left for antiarrhythmic drugs. An emerging role for antiarrhythmic drug therapy is represented by the concomitant pharmacological treatment in ICD recipients who experience shocks from their devices (hybrid therapy). Several randomized clinical trials have recently evaluated this issue and permit an evidence-based treatment strategy. Currently, most patients receive sotalol or amiodarone for hybrid therapy with azimilide as a potential new class III antiarrhythmic drug for this treatment indication.
Asunto(s)
Antiarrítmicos/uso terapéutico , Taquicardia Ventricular/tratamiento farmacológico , Terapia Combinada , Muerte Súbita Cardíaca/etiología , Muerte Súbita Cardíaca/prevención & control , Desfibriladores Implantables/efectos adversos , Electrocardiografía , Medicina Basada en la Evidencia , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto , Taquicardia Ventricular/etiologíaAsunto(s)
Antiarrítmicos/uso terapéutico , Arritmias Cardíacas/terapia , Muerte Súbita Cardíaca/prevención & control , Desfibriladores Implantables , Imidazolidinas , Amiodarona/uso terapéutico , Arritmias Cardíacas/tratamiento farmacológico , Bloqueadores de los Canales de Calcio/uso terapéutico , Ensayos Clínicos como Asunto , Enfermedad Coronaria/tratamiento farmacológico , Enfermedad Coronaria/mortalidad , Método Doble Ciego , Estudios de Seguimiento , Insuficiencia Cardíaca/tratamiento farmacológico , Insuficiencia Cardíaca/mortalidad , Ventrículos Cardíacos , Humanos , Hidantoínas , Imidazoles/uso terapéutico , Metaanálisis como Asunto , Piperazinas/uso terapéutico , Placebos , Prevención Primaria , Estudios Prospectivos , Calidad de Vida , Ensayos Clínicos Controlados Aleatorios como Asunto , Factores de Riesgo , Factores de TiempoRESUMEN
Inappropriate therapy of SVTs by ICDs remains a major clinical problem despite enhanced detection criteria like "sudden onset" and "rate stability" in third-generation devices. Electrogram morphology discrimination offers an additional approach to improve discrimination of supraventricular tachycardia (SVT) from ventricular tachycardia (VT). In a prospective, multicenter study, patients received an ICD with a beat-to-beat algorithm for morphological analysis of the intracardiac electrogram (Morphology Discrimination, MD). A nominal programmingfor standard enhancement criteria and morphology discrimination was required at implant. Electrogram storage of tachycardia episodes irrespective of delivery of therapy was used to assess sensitivity and specificity of the morphology algorithm alone and in combination with established detection criteria. During a 126 6-month follow-up, 886 episodes of device stored electrograms from 82 of 256patients were evaluated. Atnominal settings, the MD algorithm correctly identified 423 of 551 episodes as VT resulting in sensitivity of 77%. The classification of SVT was met in 239 of 335 episodes resulting in specificity of 71%. In combination with sudden onset, sensitivityincreased to 99.5% at the expense of specificity (48%). In conclusion, SVT-VT discrimination based on morphological analysis alone results in limited sensitivity and specificity. Programming the monitor mode allows individual assessment of the performance of this detection enhancement feature during clinical follow-up without compromising device safety. Only in patients with documented efficacy of morphology discrimination should this feature be subsequently activated.
Asunto(s)
Algoritmos , Desfibriladores Implantables , Taquicardia Supraventricular/diagnóstico , Taquicardia Ventricular/diagnóstico , Diagnóstico Diferencial , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Sensibilidad y Especificidad , Taquicardia Supraventricular/terapia , Taquicardia Ventricular/terapiaRESUMEN
INTRODUCTION: Atrial fibrillation (AF) is associated with significant morbidity and mortality that may be related to hemodynamic impairment, thromboembolic events, or enhanced electrical instability of the ventricular myocardium. There is, however, a lack of data concerning the association of AF and ventricular tachyarrhythmias. METHODS AND RESULTS: Consecutive patients with indication for an implantable cardioverter defibrillator (ICD) were classified for the presence or absence of persistent AF at the time of device implantation. Incidence of device therapy, stored electrograms, and clinical events during follow-up were evaluated prospectively. Two hundred fifty patients were included. During follow-up (20+/-14 months), patients in AF experienced appropriate device therapy for recurrent ventricular arrhythmias more frequently compared with patients in sinus rhythm (SR) (63% vs 38%, P = 0.01). On multivariate analysis, AF was an independent predictor of appropriate ICD therapy (relative risk 1.8; 95% confidence interval [CI] 1.2 to 2.9) and inappropriate device therapy (relative risk 2.3; 95% CI 1.2 to 4.5). Predefined clinical events (cluster endpoint: death, syncope, and hospitalizations) were observed more frequently in AF than in SR patients (55% vs 31%, P = 0.01). Analysis of device-stored electrograms revealed a higher incidence of short-long-short cycles preceding ventricular arrhythmias in AF compared with SR patients (50% vs 16%, P = 0.002). Baseline heart rate preceding ventricular arrhythmias did not differ between the two groups. CONCLUSION: AF is an independent predictor of recurrent ventricular arrhythmias in ICD recipients. The underlying electrophysiologic mechanism seems to be irregular rather than rapid ventricular activation, with a high incidence of short-long-short sequences preceding ventricular tachyarrhythmias in AF patients.
Asunto(s)
Fibrilación Atrial/terapia , Desfibriladores Implantables , Anciano , Fibrilación Atrial/complicaciones , Fibrilación Atrial/mortalidad , Fibrilación Atrial/fisiopatología , Electrofisiología , Femenino , Estudios de Seguimiento , Frecuencia Cardíaca , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Prospectivos , Recurrencia , Fibrilación Ventricular/etiologíaRESUMEN
BACKGROUND: Transvenous internal cardioversion (ICV) of atrial fibrillation (AF) may be successful after unsuccessful external CV. However, the safety and efficacy of ICV in patients with significant mitral valve disease and AF of long duration have not been evaluated prospectively. METHODS: This study included 22 consecutive patients (mean age = 59 +/- 14 years, 12 women) with mitral regurgitation grade = II (n = 14) or after mitral valve replacement (n = 8), who underwent ICV with 3/3 ms biphasic shocks delivered via two defibrillation catheters placed in the right atrium and the coronary sinus, respectively. The mean left atrial diameter was 53 +/- 7 mm (range 45-68), and AF had been diagnosed for a median of 24 months. All patients received oral amiodarone pretreatment followed by a maintenance dose of 200 mg/day. RESULTS: Sinus rhythm (SR) was restored by ICV in 15/20 patients (75%), and returned spontaneously in two patients during amiodarone pretreatment. The mean threshold for ICV was 6.2 +/- 3.5 J. Sinus node disease was present in one patient after ICV, and two patients developed amiodarone-induced hyperthyroidism. During a follow-up of 11 +/- 5 months, 8 patients had recurrent AF. The remaining 11 patients who were successfully cardioverted remained in stable SR. CONCLUSION: SR can be safely and successfully restored by ICV in patients with MVD and long-standing AF. During intermediate-term follow-up, a significant proportion of patients remained in SR with oral amiodarone therapy.