title: [Spontaneous variability of ventricular extrasystoles: criteria for validating anti-arrhythmia therapy in relation to the length of the control interval].
abstract: Calculations about the variability of PVCs are usually based upon the results of two Holter ECGs, either successive ones or separated by a short interval. No studies are available indicating whether the criteria calculated for short control intervals also holds true when evaluating chronic antiarrhythmic treatment over longer control periods. This study was performed to investigate the influence of the length of the control interval on the spontaneous variability and thus on the reduction of PVCs required to secure an antiarrhythmic effect. In a prospective study, 444 ambulatory ECGs were obtained in 90 patients with CAD or IDC and untreated ventricular arrhythmia of Lown grade IV. Patient follow-up was carried out over an average of 181 +/- 297 days. The degree of arrhythmia was expressed as the mean hourly PVC rate. The variability of PVC counts between two Holter ECGs was defined as the logarithm of the quotient PVCday 2(n + 1)/PVCday 1(n + 1). The spontaneous distribution of variability quotients was defined separately (mean +/- 2 SD) for each of four ranges of control intervals (0-6 days, 7-89 days, 90-364 days, greater than or equal to 365 days). The per cent reduction (R) in PVC frequency necessary to establish drug efficacy, was calculated according to the formula R (%) = 10(0)-10(-2SD) X 100, whereas the percentage change necessary to prove aggravation of arrhythmia (A) was assessed by the formula A (%) = 10(0)+10(+2SD X 100. R increased from 63% (0-6 days), 81% (7-89 days), 93% (90-364 days) to 98% (greater than or equal to 365 days).(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D005117:Cardiac Complexes, Premature / Q000188:drug therapy*; D002311:Cardiomyopathy, Dilated / Q000150:complications; D003327:Coronary Disease / Q000150:complications; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D000889:Anti-Arrhythmia Agents
vernacular_title: Spontanvariabilität ventrikulärer Extrasystolen: Kriterien zur Validierung einer antiarrhythmischen Therapie in Abhängigkeit von der Länge des Kontrollintervalls.