COMBINED REST AND EXERCISE ELECTROCARDIOGRAPHIC REPOLARIZATION FINDINGS IN RELATION TO STRUCTURAL AND FUNCTIONAL ABNORMALITIES IN ASYMPTOMATIC AORTIC REGURGITATION

The relationship of combined rest and exercise electrocardiographic (E GG) repolarization abnormalities to left ventricular geometry and func tion was examined in 48 patients with asymptomatic chronic pure aortic regurgitation and no recent use of digitalis. Echocardiographic and r adionuclide cineangiographic findings were compared in groups defined by the presence or absence of the ''strain'' pattern of repolarization abnormality on the resting ECG and also by the presence or absence of standard positive repolarization changes during upright treadmill exe rcise (>0.1 mV additional horizontal or downsloping ST depression). Th ese hierarchic groups demonstrated trends toward progressively abnorma l left ventricular dimensions, mass, wall stress, and change in ejecti on fraction with exercise. Although the presence of the strain pattern on the resting ECG alone was most strongly correlated with underlying functional and geometric abnormalities, an abnormal exercise test res ponse was independently associated with abnormal left Ventricular syst olic dimension. The large group of patients with no symptomes and norm al resting repolarization had only 0% to 4% prevalences of markedly in creased systolic dimension (>55 mm), reduced ejection fraction at rest (<45%), or reduced ejection fraction during exercise (<40%), whereas the small group of patients with abnormal resting repolarization and a positive exercise test response had 50% to 83% prevalences of these f indings. These data suggest a possible role for rest and exercise ECG in the serial evaluation of patients with aortic regurgitation.