Effect of intravenous infusion of iodinated contrast media on the coronary blood flow in dogs

Abstract

BackgroundCoronary computed tomography angiography (CCTA) is obtained using peripheral intravenous iodinated contrast agents (ICA) injection. There is continuing attempts to derive coronary physiological information like coronary blood flow (CBF) and/or fractional flow reserve from CCTA images. However, no data is available regarding the effect of peripheral intravenous injection of ICA on CBF. MethodsA series of 4 experiments was performed using healthy mongrel dogs. All dogs underwent anesthesia and open thoracotomy with placement of ultrasound flowmeter to one of the coronary artery to provide real time absolute CBF measurements. Different infusion protocols of Isovue-370 and Visipaque-320 were injected into a peripheral vein. Similar doses of normal saline injection were performed to be used as controls. The effect of iodinated contrast media injection on absolute coronary blood flow was monitored and recorded. ResultsInjection of normal saline in the peripheral vein did not produce any significant increase in CBF. Peripheral intravenous injection of ICA resulted in a consistent increase of 40–73% in absolute CBF as recorded 5minutes post-contrast administration. The contrast effect starts about 30seconds and peaks at about 2minutepost-contrast injection then slowly fades away in the following 10–15min. The increase in the CBF was dose related. There was greater increase in the CBF to 50ml infusion compared to 25ml infusion of both Visipaque and Isovue. ConclusionsPeripheral venous administration of iodinated contrast-media in dogs results in a dose related, significant and prolonged increase in CBF.