Relationship Between Exercise-Induced T Wave Abnormalities and Major Cardiac Event

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Abstract

Objectives

The aim of the study was to analyze exercise-induced T wave abnormalities prevalence and if the induced T wave abnormalities were independent predictors of a major cardiac event related to myocardial ischemia in the ^99mTc sestamibi SPECT tomograms.

Material and method

We prospectively included 2425 consecutive patients with ^99mTc sestamibi SPECT studies. We considered T wave pseudonormalization and a new T wave invertion during exercise electrocardiogram and we analyzed both groups of patients, without any other changes on the electrocardiogram. The interpretation of the SPECT tomograms was done without the exercise electrocardiogram results and then we classified the images as ischemic or non ischemic. One-year follow up for cardiovascular events was done. Values are given as media and percentages. Chi square test was used for the statistical analysis. When p values were below 0.05the difference was considered significant.

Results

Seventy-three (3%)of the 2425 patients had exercise induced T wave abnormalities and 32 (44%) patients had myocardial ischemia on the SPECT tomograms. Twenty-two (69%) patients had T wave pseudo-normalization and 10 (31%) hada new T wave inversion. Eighty five percent of the followup (mean 12 months) free of deaths. When we analyzed cardiovascular events and exercise induced T wave abnormalities on the overall followup, 13 of 32 (40%) patients with induced myocardial ischemia at the SPECT images, had cardiovascular events. Of the 41 patients without induced myocardial ischemia, only 2 (4.8%) had cardiovascular events (p<0.0005).

Conclusions

In this cohort of patients with coronary artery dis-ease, the exercise induced T wave abnormalities was not an independent predictor or futur major cardiac event related to the presence of myocardial ischemia in the SPECT tomograms.