Exercise-induced ST segment elevation in Q wave leads in postinfarction patients: Defining its meaning and utility in today's practice

Most attempts to identify qualitative and quantitative techniques for asses sing myocardial viability and the likelihood of improved function after rev ascularization in patients with healed myocardial infarcts have focused on treatment strategies and prognosis. This review examines the true value of the electrocardiographic phenomenon of exercise-induced ST segment elevatio n (EISTE) in Q wave leads as a diagnostic tool for the assessment of myocar dial viability. The prognostic potential and clinical utility of the EISTE phenomenon are inhibited both by the heart's electrophysiologic response to exercise-induced metabolic and hemodynamic changes, and by the ECG's limit ed facility in assessing myocardial preservation. The use of EISTE as an in dependent indicator for surgical intervention is proscribed by these limita tions. The EISTE phenomenon could serve as a useful tool in the first line of discrimination in patients with healed Q wave myocardial infarction, and may justify further diagnostic work-up in patients under consideration for a revascularization procedure. In the era of sophisticated nuclear and ech o techniques, accurate imaging studies should not be replaced by ECG analys is alone in the search for viable tissue, except when financial costs are o f major importance. Copyright (C) 2000 S. Karger AG. Basel.