Noninvasive assessment and management of the patient at high risk of sudden cardiac death.
Evaluation of the patient who may be at high risk of sudden death includes consideration of symptoms, exercise testing, ambulatory electrocardiographic monitoring, and programmed electrical stimulation. The optimal approach to patients with potentially life-threatening ventricular arrhythmia is controversial. Programmed electrical stimulation may be the only useful method of assessment when there is marked biological variability of arrhythmia or when there is insufficient spontaneous or exercise-induced arrhythmia. Ambulatory electrocardiographic monitoring may document the arrhythmia/event, but more often relies upon the identification of a warning or marker arrhythmia. Current prognostic classifications grade the frequency of ventricular ectopy and presence of repetitive forms. Differentiation of pathogenetic and associated or marker arrhythmia as well as consideration of the type and stage of cardiac disease and the potential role of the autonomic nervous system may improve our ability to stratify risk for subsequent events and sudden death. Effective treatment aims to prevent recurrence and to improve mortality. The current approach relies on the abolition of marker arrhythmias or on their reduction by statistically determined amounts. In postmyocardial infarction patients, the efficacy of such therapy has not been determined. Large prospective, randomized studies in well characterized patients are required. The majority of patients with hypertrophic cardiomyopathy die suddenly. In the adult the finding of nonsustained ventricular tachycardia on electrocardiographic monitoring is a sensitive and specific marker of high risk and treatment of such patients with low-dose amiodarone is associated with improved survival. Characterization of patients with dilated cardiomyopathy has failed to identify a treatable pathogenetic feature of poor prognosis.(ABSTRACT TRUNCATED AT 250 WORDS)
McKenna
W J
WJ
Cardiovascular Disease Unit, Royal Postgraduate Medical School, London, United Kingdom.
D009202:Cardiomyopathies / Q000150:complications / Q000175:diagnosis* / Q000401:mortality; D003327:Coronary Disease / Q000150:complications / Q000175:diagnosis* / Q000401:mortality; D003645:Death, Sudden / Q000209:etiology; D004452:Echocardiography; D004562:Electrocardiography; D015716:Electrocardiography, Ambulatory; D005080:Exercise Test; D006801:Humans; D011379:Prognosis; D012307:Risk Factors