Effects of dipyridamole and aminophylline on hemodynamics, regional myocardial blood flow and thallium-201 washout in the setting of a critical coronary stenosis

Journal Article · Fri Nov 30 23:00:00 EST 1990 · Journal of the American College of Cardiology; (USA)

DOI:https://doi.org/10.1016/0735-1097(90)90331-I· OSTI ID:6273276

Granato, J E; Watson, D D; Belardinelli, L; Cannon, J M; Beller, G A ^[1]

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1. Univ. of Virginia Health Sciences Center, Charlottesville (USA)

Experiments were performed to characterize the interaction of intravenous dipyridamole and aminophylline on thallium-201 transport kinetics, regional myocardial blood flow and systemic hemodynamics in the presence of a critical coronary artery stenosis. In 12 dogs with a critical left anterior descending coronary artery stenosis, arterial pressure decreased from a mean value (+/- SEM) of 107 +/- 6 to 94 +/- 3 mm Hg and distal left anterior descending artery pressure decreased from 70 +/- 7 to 55 +/- 4 mm Hg after intravenous administration of dipyridamole. In the left anterior descending perfusion zone, the endocardial/epicardial flow ratio decreased from 0.70 to 0.36 and the intrinsic thallium washout rate was significantly prolonged. Intravenous aminophylline reversed the dipyridamole-induced systemic hypotension and transmural coronary steal and restored the thallium washout rate to baseline values. In six other dogs, aminophylline alone resulted in no alterations in systemic and coronary hemodynamics or regional myocardial blood flow. As expected, dipyridamole-induced vasodilation and coronary steal were prevented by aminophylline pretreatment. These data show that in a canine model of partial coronary stenosis, systemic hypotension, adverse regional flow effects and prolonged thallium-201 washout consequent to intravenously administered dipyridamole are promptly reversed by intravenous aminophylline administration. Aminophylline alone had no significant hemodynamic and coronary flow effects. This study provides further insight into the altered thallium kinetics occurring as a consequence of dipyridamole-induced vasodilation and suggests that the prompt reversal of symptoms and signs of ischemia with aminophylline in patients receiving intravenous dipyridamole for clinical imaging studies probably reflects the reversal of transmural coronary steal.

• OSTI ID: 6273276
• Journal Information: Journal of the American College of Cardiology; (USA), Journal Name: Journal of the American College of Cardiology; (USA) Vol. 16:7; ISSN 0735-1097; ISSN JACCD
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
ANIMALS
ARTERIES
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL EFFECTS
BIOLOGICAL MODELS
BLOOD FLOW
BLOOD VESSELS
BODY
CARDIOVASCULAR AGENTS
CARDIOVASCULAR DISEASES
CARDIOVASCULAR SYSTEM
CORONARIES
DAYS LIVING RADIOISOTOPES
DISEASES
DIURETICS
DOGS
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
EXERCISE
HEART
HEAVY NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
KINETICS
MAMMALS
MUSCLES
MYOCARDIUM
NUCLEI
ODD-EVEN NUCLEI
ORGANS
RADIOISOTOPES
REACTION KINETICS
SECONDS LIVING RADIOISOTOPES
THALLIUM 201
THALLIUM ISOTOPES
VASODILATORS
VERTEBRATES