title: Late potentials and ejection fraction at hospital discharge: prognostic value in thrombolyzed and non-thrombolyzed patients. A preliminary report. The Belgian Working Group for Signal Averaging.
abstract: The prognostic value of the use of thrombolytic therapy (TL), the ejection fraction (EF) and the presence of late potentials (LP) in the signal-averaged ECG (filter less than 40 Hz) at the time of hospital discharge was assessed in a multicenter prospective study. This report presents the follow-up at 4 months of the first 263 patients. Thrombolytic therapy was given to 41%. The mean ejection fraction was 45%. The average duration of the high frequency QRS complex (HFQRS) was 104 ms. The mean duration of the terminal signal under 40 microV (D40) was 31 ms. The combination of both HFQRS greater than 110 ms and a D40 greater than 40 ms was considered as presence of LP. The cardiac mortality at 4 months was 5.7% (15 patients). Late ventricular tachycardia or fibrillation occurred in 2.3% (6 patients). The relative risk (RR) for cardiac death or late events was 5.14 with a 95% confidence interval (CI) of 1.2 to 22.0 when no thrombolytic therapy was used. The RR was 3.39 (CI: 1.4 to 8.4) for patients with an EF lower than 30%. The single most important electrocardiographic parameter was a D40 greater than 40 ms (RR: 3.14, CI: 1.3 to 7.8). The presence of LP had a RR of 4.28 (CI: 1.7 to 10.5). With stepwise regression analysis it was evident that cardiac function and information obtained by signal averaging offered independent prognostic information. The presence of LP at hospital discharge after acute infarction offers additional prognostic information to EF for the risk of later cardiac death, especially in patients without thrombolysis.
authors.affiliation: University of Ghent.
authors.forename: L
authors.initials: L
authors.lastname: Jordaens
authors.forename: P
authors.initials: P
authors.lastname: Schoenfeld
authors.forename: C
authors.initials: C
authors.lastname: Demeester
authors.forename: P
authors.initials: P
authors.lastname: Bethume
authors.forename: C
authors.initials: C
authors.lastname: Mahieu
authors.forename: P
authors.initials: P
authors.lastname: Block
mesh_terms: D000368:Aged; D001530:Belgium; D016757:Death, Sudden, Cardiac / Q000209:etiology / Q000517:prevention & control; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology*; D010351:Patient Discharge; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D012306:Risk; D013318:Stroke Volume; D015912:Thrombolytic Therapy; D013997:Time Factors