Time domain analysis of the signal averaged electrocardiogram to detect late potentials in heart failure patients with different etiologies.

Autor: Grell Ede S; Instituto do Coração, Hospital das Clínicas, FMUSP, São Paulo, SP, Brazil. egrell@cardiol.br, de Paula RS, Tobias NM, Moffa PJ, Grupi CJ, Mansur AJ
Jazyk: English; Portuguese
Zdroj: Arquivos brasileiros de cardiologia [Arq Bras Cardiol] 2006 Sep; Vol. 87 (3), pp. 241-7.
DOI: 10.1590/s0066-782x2006001600003
Abstrakt: Objective: To evaluate the frequency, clinical correlations and prognosis influence of late potentials on the of heart failure patients with different etiologies using the signal averaged electrocardiogram.
Methods: A 42 month study of the signal averaged electrocardiograms of 288 heart failure patients with different etiologies was conducted. The group of patients included 215 males (74.65%) and 73 females (25.35%) between the ages of 16 and 70 (mean 51.5, standard deviation 11.24). The heart failure etiologies were: hypertensive heart disease (78 patients, 27.1%); idiopathic dilated cardiomyopathy (73 patients, 25.4%); ischemic cardiomyopathy (65 patients, 22.6%); Chagas disease (42 patients, 14.6%); alcoholic cardiomyopathy (9 patients, 3.1%); peripartum cardiomyopathy (6 patients, 2.1%); valvular heart disease (2 patients, 4.2%) and viral myocarditis (3 patients, 1.04%). The variables included the duration of the standard QRS complex, duration of the filtered QRS complex, duration of the signal below 40 microV and the root mean square of the last 40 ms which were analyzed in regard to age, gender, etiology and mortality as well as the findings of the 12-lead electrocardiogram at rest, echocardiogram and ambulatory electrocardiogram. The statistical analysis tests used were: the Fisher exact probability test, Students t-test, Mann Whitney test, variance analysis, Log-Hank and the Kaplan-Meyer method.
Results: Late potentials were diagnosed in 90 patients (31.3%) and there was no association with the etiologies. The presence of this condition is associated with: a lower maximum oxygen uptake during the ergospirometry (p=0.001); sustained and non-sustained ventricular tachycardia during Holter monitoring (p=0.001), sudden death and mortality (p<0.05). Patients that did not present late potentials had a higher overlife rate.
Conclusion: The presence of late potentials was not associated with the etiologies and proved to be an indication of a worse prognosis.
Databáze: MEDLINE