Dipyridamole cardiac imaging

Journal Article · Mon Feb 01 04:00:00 EST 1988 · Am. Heart J.; (United States)

DOI:https://doi.org/10.1016/0002-8703(88)90492-9· OSTI ID:5271335

Iskandrian, A S; Heo, J; Askenase, A; Segal, B L; Auerbach, N

Dipyridamole cardiac imaging is a useful alternative technique to exercise stress testing in the evaluation of patients with ischemic heart disease. Intravenous dipyridamole is still in the investigational phase, while oral dipyridamole is widely available. The hemodynamic effects of dipyridamole include an increase in coronary blood flow (due to coronary vasodilation) which is in excess of the increase in myocardial oxygen consumption and cardiac output. The disparity in the increase in coronary blood flow relative to the cardiac output results in an increase in myocardial thallium activity and an increase in the myocardial/background activity ratio. The quality of the thallium images is better or similar to that of exercise thallium images. The optimal dose of intravenous dipyridamole is 0.56 mg/kg, and of the oral dose it is 300 to 400 mg, although higher doses may be necessary in some patients. Analysis of the thallium images has been to a large extent based on visual inspection of the planar images. Delayed images are helpful to establish the nature of the perfusion abnormalities (transient or fixed). The process of redistribution is based on disparate rates of washout from the normal and abnormal zones. The sensitivity and specificity of dipyridamole thallium imaging, whether intravenous or oral, have been shown in a number of studies to be quite adequate and comparable to that achieved during exercise thallium imaging. Dipyridamole two-dimensional echocardiography has also been used in the detection of coronary artery disease; transient (new or worsening of preexisting) wall motion abnormalities have been found to be a specific marker of coronary artery disease. Transmural as well as regional coronary steal phenomena have been postulated as the mechanism for dipyridamole-induced regional wall motion abnormalities. 65 references.

• Research Organization: Presbyterian-Univ. of Pennsylvania Hospital, Philadelphia (USA)
• OSTI ID: 5271335
• Journal Information: Am. Heart J.; (United States), Journal Name: Am. Heart J.; (United States) Vol. 115:2; ISSN AHJOA
• Country of Publication: United States
• Language: English

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62 RADIOLOGY AND NUCLEAR MEDICINE
ANIMALS
BLOOD FLOW
BODY
CARDIOVASCULAR AGENTS
CARDIOVASCULAR DISEASES
CARDIOVASCULAR SYSTEM
COUNTING TECHNIQUES
DIAGNOSIS
DISEASES
DOGS
DRUGS
HEART
IMAGE PROCESSING
INJECTION
INTAKE
INTRAVENOUS INJECTION
ISCHEMIA
ISOTOPES
MAMMALS
ORAL ADMINISTRATION
ORGANS
PATIENTS
PROCESSING
RADIOISOTOPE SCANNING
THALLIUM ISOTOPES
ULTRASONOGRAPHY
VASCULAR DISEASES
VASODILATORS
VERTEBRATES