Retraso de la rama descendente de la onda T en electrocardiogramas sin datos de riesgo aparente de muerte súbita

Abstract

Introduction: Prolongation of the descending branch of the T-wave in the electrocardiogram (ECG) has been identified to be able to determine the risk for sudden death of cardiac origin, but its importance in the general population is not known. Objective: To provide a tool for easy acquisition and effective application to identify the risk of sudden death in the general population. Method: We measured the dbT/jT index (descending branch of the T wave/space between the j point and the end of T), and it was found to be completely normal in 400 ECGs, 656 had alterations that don’t affect ventricular repolarization, and 82 had branch block. We carried out the Z transformation of the nonparametric distribution curves and calculated the Z ratio to data far from the mean value. Results: The distribution was asymmetric, with no difference in the three groups. The Z transformation showed a mean value of 30 ± 7, which suggests that 95% of the population has a dbT/jT index < 0.45. Conclusion: dbT/jT index results > 0.44 are beyond two standard deviations and are therefore abnormal, which should prompt specialized assessment in order to determine if there is risk for death in the carrier.