[Coronary vasoconstriction induced by digoxin in normal subjects and in patients with coronary atherosclerosis].
This study evaluated the effects of digoxin infusion (0.014 mg/kg in 10 min i.v.) on large coronary arteries measured by quantitative digital angiography. Twenty-two patients (aged 47 +/- 12), divided in 3 groups were studied. The effects of digoxin infusion (after 10 and 20 min) and sublingual administration of isosorbide dinitrate were investigated in Group I (patients with angiographically normal coronary arteries, n = 9) and in Group II (patients with atherosclerotic coronary arteries, n = 8). In Group III (n = 5) to determine whether or not the effects of digoxin were mediated by activation of alpha-adrenergic receptors, coronary angiographies were performed after alpha-adrenoceptor blockade (phentolamine 0.11 mg/kg, i.v.). In Group I, 10 min after the end of digoxin infusion, cross-sectional area decreased from 7.7 +/- 4.1 mm2 to 6.0 +/- 2.2 mm2, and after 20 min to 5.6 +/- 2.6 mm2 (p < 0.05). Isosorbide dinitrate reverted digoxin-induced vasoconstriction as cross-sectional area increased to 8.5 +/- 3.4 mm2 (NS versus baseline). By 20 min after digoxin infusion heart rate was significantly reduced from 79 +/- 16 to 74 +/- 13 b/min (p < 0.01). Peripheral vascular resistances increased significantly 10 min after digoxin infusion (from 1396 +/- 693 to 1693 +/- 984 dyne*s*cm-5, p < 0.05), whereas cardiac output did not change. In Group II, minimal stenosis diameter decreased significantly 20 min after digoxin infusion from 1.6 +/- 0.5 mm to 1.4 +/- 0.5 mm (p < 0.05). Again, isosorbide dinitrate reverted digoxin-induced vasoconstriction as minimal stenosis diameter increased (NS versus control).(ABSTRACT TRUNCATED AT 250 WORDS)
Rapacciuolo
A
A
Cattedra di Cardiologia, II Facoltà di Medicina e Chirurgia, Università degli Studi Federico II, Napoli.
Indolfi
C
C
Esposito
G
G
Di Lorenzo
E
E
Esposito
N
N
Maione
A
A
Ambrosini
V
V
Piscione
F
F
Chiariello
M
M
D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D017023:Coronary Angiography / Q000295:instrumentation / Q000379:methods; D003324:Coronary Artery Disease / Q000097:blood / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000503:physiopathology*; D003331:Coronary Vessels / Q000187:drug effects*; D004077:Digoxin / Q000097:blood / Q000494:pharmacology*; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects / Q000502:physiology; D012016:Reference Values; D014661:Vasoconstriction / Q000187:drug effects*
D011942:Receptors, Adrenergic, alpha; D004077:Digoxin