Postextrasystolic T wave change to stratify risk of pump failure death in patients with chronic heart failure

The postextrasystolic T wave change (PEST) is an electrocardiographic phenomenon in which the morphology of the normal T wave is altered for a short time after a ventricular ectopic beat (VEB). It has been observed in patients with other cardiac pathologies but it has not been proposed as a risk index for cardiac death. Since PEST seems to be potentiated in patients with depression of myocardial contractility, we hypothesize that PEST could be used to predict pump failure death (PFD) in patients with chronic heart failure (CHF). For the purpose of quantifying PEST, the parameters morphological change onset (MCO) and morphological change slope (MCS) were introduced. MCO describes an initial morphological change of the T wave after a VEB, while MCS is responsible for the description of the restitution to its original shape. 537 records from the MUSIC study were separated according to their cause of death and comparisons against the others (including survivors) were carried out. In addition, receiver operating characteristic (ROC) curves were used to determine the optimal separating thresholds for MCO and MCS that maximized the sum of sensitivity and specificity for PFD risk prediction. The results showed that no significant differences could be established and the proposed parameters do not seem to be related to any kind of cardiac death. In future, other forms of PEST quantification together with more databases can be used to definitely conclude that PEST has no predictive power.