title: ST segment alternans during coronary angioplasty.
abstract: Four patients with severe proximal or mid-LAD stenosis were noted to have ST alternans during balloon angioplasty. Neither mechanical alternans nor increased ventricular ectopy were noted. In contrast to prior descriptions in animals or patients with variant angina, ST alternans did not occur following a premature ventricular contraction. Frequent use of calcium channel blockers during PTCA may interfere with the mechanism leading to electrical alternans and its consequences as seen in animal studies, accounting for the low frequency with which this phenomenon is noted during PTCA.
authors.affiliation: University of Chicago Hospitals, Department of Medicine, Hans Hecht Hemodynamics Laboratory, Illinois 60637.
authors.forename: M
authors.initials: M
authors.lastname: Sochanski
authors.forename: T
authors.initials: T
authors.lastname: Feldman
authors.forename: K G
authors.initials: KG
authors.lastname: Chua
authors.forename: A
authors.initials: A
authors.lastname: Benn
authors.forename: R
authors.initials: R
authors.lastname: Childers
mesh_terms: D000328:Adult; D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D001145:Arrhythmias, Cardiac / Q000503:physiopathology*; D004562:Electrocardiography / Q000295:instrumentation*; D005260:Female; D006352:Heart Ventricles / Q000503:physiopathology; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000503:physiopathology / Q000628:therapy*; D012815:Signal Processing, Computer-Assisted