[Stratification of the arrhythmia risk after acute myocardial infarct].
Recent studies clearly support the role of the cardioverter implantable defibrillator in reducing arrhythmic and all-cause mortality in patients with a previous myocardial infarction. However, the use of the cardioverter implantable defibrillator cannot be extended to all myocardial infarction patients despite its effectiveness because implantation is an invasive procedure and the cost of the device is high. Thus, the correct and effective identification of patients at high risk of life-threatening ventricular arrhythmias represents a clinically relevant problem owing to the availability of an effective but expensive therapeutic tool. Many non-invasive tests have been studied in past years to assess the risk of ventricular arrhythmias after myocardial infarction; moreover, also programmed ventricular stimulation has been used to evaluate inducibility of ventricular tachycardia. Nevertheless, the positive predictive value of both non-invasive and invasive testing is low and not adequate to make a clinical decision. This finding is probably related to the multifactorial genesis of malignant ventricular arrhythmias which need several concomitant factors to trigger arrhythmias. For this reason the combined use of multiple risk markers is needed in order to improve diagnostic accuracy and identify subgroups of patients at high enough risk to define specific prophylactic options. In this scenario, according to available data, patients with two or more non-invasive risk markers should undergo electrophysiologic testing. In fact, patients with a recent myocardial infarction who have positive non-invasive tests and also show inducibility of sustained monomorphic ventricular tachycardia at programmed ventricular stimulation have a high incidence of arrhythmic events during the subsequent follow-up period and, in the author's opinion, should undergo a cardioverter defibrillator implantation. In the present review, an analysis of the main diagnostic tests for risk stratification of postinfarction patients will be performed and operative suggestions will be provided.
Pedretti
R F
RF
Divisione di Cardiologia, Fondazione Salvatore Maugeri, Clinica del Lavoro e della Riabilitazione, IRCCS, Istituto Scientifico, Via Roncaccio, 16, 21049 Tradate, VA. rpedretti@fsm.it
D002037:Bundle-Branch Block / Q000150:complications; D017147:Defibrillators, Implantable; D004562:Electrocardiography; D005343:Fibrinolytic Agents / Q000627:therapeutic use; D006339:Heart Rate; D006801:Humans; D009203:Myocardial Infarction / Q000150:complications* / Q000401:mortality / Q000503:physiopathology; D017202:Myocardial Ischemia / Q000150:complications; D011311:Pressoreceptors / Q000502:physiology; D012018:Reflex / Q000502:physiology; D012307:Risk Factors; D013318:Stroke Volume; D014693:Ventricular Fibrillation / Q000209:etiology* / Q000401:mortality / Q000628:therapy
D005343:Fibrinolytic Agents