[Significance of ST segment and R wave changes in exercise-induced supraventricular extrasystole]

In a retrospective study the importance of ST segment and R wave changes in sinus beats and in supraventricular extrasystoles was examined in 23 patients who had exhibited supraventricular extrasystoles during exercise testing and who had undergone coronary arteriography in 1993 and 1994. Significant coronary artery disease was detected in 18 patients (group A), whereas 5 subjects (group B) had no demonstrable obstructive lesions. In every patient the authors measured the ST depression and R wave amplitude of the supraventricular extrasystole (STe and Re, respectively), and of the preceding sinus beat (STs and Rs, respectively), and than they calculated the difference between the two [ST(e-s) and R(e-s), respectively]. The ST(e-s) + R(e-s) value was higher than zero mV in 13 patients in group A, and in neither case in group B. Among the 4 patients in group A with false negative results of exercise tests, 3 had a positive ST(e-s) + R(e-s) value, whereas the only patient in group B with false positive exercise test result had a negative ST(e-s) + R(e-s) value. In patients with exercise induced supraventricular extrasystoles, the changes of ST depression and R wave amplitude in the extrasystoles and in the preceding sinus beats, may supplement the criterions of a positive examination.