In:
Circulation, Ovid Technologies (Wolters Kluwer Health), Vol. 49, No. 3 ( 1974-03), p. 517-521
Abstract:
Controversy exists over the rapidity of onset of the inotropic effect of various digitalis glycosides. Shortening of the systolic time intervals (STI) provides a quantitative measure of the inotropic effect of digitalis glycosides in human subjects. Total electromechanical systole corrected for heart rate (QS 2 I) is the most sensitive of the STI since it combines the shortening effect of digitalis glycosides on both the pre-ejection period and ejection time. Normal volunteer subjects were studied serially following i.v. injection of 1.6 mg cedilanid-D (C) (n = 18), 1.0 mg ouabain (O) (n = 12), 1.6 mg digoxin (D) (n = 16), and 1.6 mg digitoxin (DT) (n = 9). The shortening of QS 2 I was corrected for the molecular weight of the digitalis glycoside. The onset of shortening of the QS 2 I/ mole proved to be exponential for each digitalis glycoside. This allowed estimation of the maximum shortening of QS 2 I/mole (A) which would occur assuming zero excretion, from which the time constant (t c ) of the curves could be determined. There was no significant difference in A among the digitalis glycosides. The t c , were 5.8 min (O), 7.2 min (C), 23 min (D), and 56 min (DT). These t c were significantly different except for O and C. Thus both C and O have a rapid onset of activity which is significantly shorter than either D or DT. The t c for C in patients with congestive heart failure is the same as normals. This study provides a heretofore unavailable, accurate measure of the differences among commonly used glycosides.
Type of Medium:
Online Resource
ISSN:
0009-7322
,
1524-4539
DOI:
10.1161/01.CIR.49.3.517
Language:
English
Publisher:
Ovid Technologies (Wolters Kluwer Health)
Publication Date:
1974
detail.hit.zdb_id:
1466401-X
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