Intraventricular conduction delay: a prognostic marker in chronic heart failure

Chronic heart failure (CHF) is associated with high mortality, and there ar e several established clinical and laboratory parameters that predict morta lity in CHF. The purpose of this study was (a) to identify the best ECG par ameter that predicts mortality, (b) to evaluate the prognostic marker of EC G against well-established indicators of prognosis. Relevant data from 241 CHF patients were analysed retrospectively. Cardiopulmonary exercise testin g and radionuclide ventriculogram were also performed where possible. The m ean follow-up period was 31 months. On univariate analysis by the Cox propo rtional Hazard method, intraventricular conduction delay (IVCD) [P<0.0001, hazard ratio 1.017 (1.011-1.024)] and QTc [P<0.0001, hazard ratio 1.012 (1. 006-1.017)] were identified as predictors of mortality. On bivariate analys is, IVCD and MVO2 were better predictors when combined together. A model ba sed on multivariate analysis showed that IVCD, MVO2 and left ventricular ej ection fraction (LVEF) were the best predictors of mortality. The addition of plasma sodium, age and NYHA class had no added benefit on the predictive power of the model. Further analysis of IVCD and QTc showed that, for diff erent cut-off values, IVCD is better than QTc, and that there is a graded i ncrease in mortality with increasing value of IVCD. We have found that IVCD is an important ECG predictor of prognosis in patients with CHF. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.