Effects of acute K-strophantidin administration on left ventricular relaxation and filling phase in coronary artery disease.
In 10 patients with coronary artery disease, preserved left ventricular (LV) performance and absence of previous myocardial infarction, the effects of an acute intravenous administration of k-strophantidin (0.005 mg/kg over 10 minutes) on selected parameters of both LV systolic and diastolic function, including relaxation, were evaluated. An increase in positive first derivative of LV pressure (dP/dt) and in the ratio between dP/dt and the pressure developed (dP/dt/P) (1,530 +/- 287) 1,600 +/- 329 mm Hg/s [p less than 0.05], and 30 +/- 6 to 34 +/- 8 s-1 [p less than 0.05], respectively) demonstrated the inotropic effect of k-strophantidin, whereas volumetric parameters of systolic function (end-systolic and stroke volume indexes, and ejection fraction) did not show any significant change. However, LV relaxation was impaired by k-strophantidin injection; in fact, mean values of T constant were significantly increased from 50 +/- 12 to 55 +/- 13 ms (p less than 0.01). Lowest LV and end-diastolic pressures increased from 8 +/- 4 to 11 +/- 4 mm Hg (p less than 0.05) and from 17 +/- 6 to 20 +/- 8 mm Hg (p less than 0.05), respectively. The end-diastolic volume and maximal rate of volumetric increase during the early and late filling phases were not modified by k-strophantidin. Mean aortic pressure increased from 110 +/- 10 to 120 +/- 12 mm Hg (p less than 0.001). Therefore, in patients with coronary artery disease and LV preserved performance, an acute intravenous administration of k-strophantidin appears to stimulate contractility and to worsen relaxation, and minimal LV and end-diastolic pressures.
Bolognesi
R
R
Cattedra di Cardiologia, Università degli Studi di Parma e Brescia, Italy.
Cucchini
F
F
Javernaro
A
A
Zeppellini
R
R
Manca
C
C
Visioli
O
O
D000368:Aged; D003327:Coronary Disease / Q000503:physiopathology*; D003971:Diastole / Q000187:drug effects*; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D013328:Strophanthins / Q000008:administration & dosage / Q000494:pharmacology*; D016277:Ventricular Function, Left / Q000187:drug effects*
D013328:Strophanthins; C029082:strophanthin K