title: Significance of R wave changes in exercise-induced supraventricular extrasystoles. Angiographic correlates.
abstract: To evaluate the clinical significance of observed R wave amplitude changes in exercise-induced supraventricular extrasystoles in comparison to the preceding sinus beat, 94 patients catheterized for possible coronary artery disease (CAD) were studied. Significant CAD was documented in 63 patients--34 with myocardial infarction (group A1) and 29 without (group A2)--whereas 31 patients had normal coronary arteries or coronary lesions less than 30% (group B). All patients underwent treadmill stress testing using the Bruce protocol within a month after cardiac catheterization. R wave amplitude increased or remain unchanged in extrasystole (R(x-s) > or = 0) in patients with CAD, while it decreased (negative R(x-s) in patients without significant CAD (P < .0001). In patients with CAD R(x-s) values were positively related to the number of obstructed coronary arteries (P < .01), while no significant difference was found between groups A1 and A2. The correlations of R wave amplitude changes in extrasystoles were significant with coronary obstruction score values (r = .82 and .85 in groups A1 and A2, respectively) and with left ventricular ejection fraction values (r = -.88, -.86 and -.90 in groups A1, A2, and B, respectively). R(x-s) > or = 0 value had a sensitivity of 79% and a specificity of 90% for CAD detection, while sensitivity was higher (89%) and specificity was lower (57%) for the prediction of left ventricular dysfunction. It is concluded that R(x-s) > or = 0 value is indicative of CAD, multivessel disease, and poor left ventricular performance, while its negative value is combined with minimal or no CAD and normal ejection fraction values.
authors.affiliation: University Cardiac Unit, Hippokrateion General Hospital, Athens, Greece.
authors.forename: A P
authors.initials: AP
authors.lastname: Michaelides
authors.forename: G P
authors.initials: GP
authors.lastname: Vyssoulis
authors.forename: P G
authors.initials: PG
authors.lastname: Paraskevas
authors.forename: C G
authors.initials: CG
authors.lastname: Skouros
authors.forename: E G
authors.initials: EG
authors.lastname: Tsiamis
authors.forename: P K
authors.initials: PK
authors.lastname: Toutouzas
mesh_terms: D000328:Adult; D000368:Aged; D005117:Cardiac Complexes, Premature / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology*; D017023:Coronary Angiography; D003327:Coronary Disease / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000503:physiopathology; D004562:Electrocardiography; D005080:Exercise Test; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged