title: Diurnal change of giant negative T wave in patients with hypertrophic cardiomyopathy.
abstract: To examine the diurnal change of negative T wave (deeper than 10 mm in precordial leads) in apical hypertrophic cardiomyopathy and the mechanism of giant negative T wave, 24-h ambulatory electrocardiographic monitoring was performed in 8 patients with apical hypertrophic cardiomyopathy, and effect of atropine on electrocardiogram was studied. The mean depth of negative T wave at 1, 2, and 3 P.M. was 9.3 +/- 3.0 mm, and that at 1, 2, and 3 A.M. was 12.6 +/- 4.8 mm. The mean R-R interval at 1, 2, and 3 P.M. was 792 +/- 113 ms and that at 1, 2, and 3 A.M. was 1055 +/- 94 ms. In seven patients (88%), negative T wave was deeper during the night than during the daytime. There was a positive correlation between R-R interval and depth of negative T wave in 6 patients (75%). Despite significant shortening of R-R interval (879 +/- 116 to 804 +/- 110 ms, p less than 0.05), atropine did not significantly change the depth of negative T wave (14 +/- 5 to 14 +/- 5 mm). In conclusion, negative T wave is not fixed, but is variable, diurnally, probably due to the change of sympathetic tone.
authors.affiliation: Department of Internal Medicine, University of Tsukuba, Ibaraki, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Iida
authors.forename: Y
authors.initials: Y
authors.lastname: Sugishita
authors.forename: K
authors.initials: K
authors.lastname: Yukisada
authors.forename: I
authors.initials: I
authors.lastname: Ito
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001285:Atropine / Q000494:pharmacology; D002311:Cardiomyopathy, Dilated / Q000503:physiopathology*; D002940:Circadian Rhythm; D004562:Electrocardiography; D015716:Electrocardiography, Ambulatory; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D001285:Atropine