Digoxin-induced vasoconstriction of normal and atherosclerotic epicardial coronary arteries.
This study evaluated the effect of bolus infusion of digoxin (0.014 mg/kg in 10 minutes, intravenously) on large coronary arteries measured by quantitative digital angiography. Twenty-two patients (mean age +/- standard deviation 47 +/- 12 years) divided into 3 groups were studied. The effects of digoxin infusion (after 10 and 20 minutes) 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). To determine whether the effects of digoxin were mediated by activation of alpha-adrenergic receptors, coronary angiography was performed in group III after alpha-adrenoceptor blockade (phentolamine 0.11 mg/kg, intravenously) (n = 5). Ten minutes after the end of digoxin infusion, the cross-sectional area decreased from 7.7 +/- 4.1 to 6.0 +/- 2.2 mm2, and after 20 minutes to 5.6 +/- 2.6 mm2 (p less than 0.05) in group I. Isosorbide dinitrate reverted digoxin-induced vasoconstriction as cross-sectional area increased to 8.5 +/- 3.4 mm2 (p = not significant versus baseline). Twenty minutes after digoxin infusion, heart rate significantly decreased from 79 +/- 16 to 74 +/- 13 beats/min (p less than 0.01). Ten minutes after digoxin infusion, peripheral vascular resistance increased significantly from 1,396 +/- 693 to 1,693 +/- 984 dynes.s.cm-5 (p less than 0.05), whereas cardiac output did not change. Twenty minutes after digoxin infusion, minimal stenosis diameter decreased significantly from 1.6 +/- 0.5 to 1.4 +/- 0.5 mm (p less than 0.05) in group II.(ABSTRACT TRUNCATED AT 250 WORDS)
Indolfi
C
C
Department of Medicine, 2nd School of Medicine, University Federico II, Napoli, Italy.
Piscione
F
F
Russolillo
E
E
Villari
B
B
Golino
P
P
Ambrosini
V
V
Condorelli
M
M
Chiariello
M
M
D015901:Angiography, Digital Subtraction; D017023:Coronary Angiography; D003324:Coronary Artery Disease / Q000503:physiopathology*; D003331:Coronary Vessels / Q000187:drug effects* / Q000502:physiology; D004077:Digoxin / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007548:Isosorbide Dinitrate / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D010646:Phentolamine; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects / Q000502:physiology*; D014661:Vasoconstriction / Q000187:drug effects*
D011942:Receptors, Adrenergic, alpha; D004077:Digoxin; D007548:Isosorbide Dinitrate; D010646:Phentolamine