Angiographic Contrast Media Research Articles

Slow response induced in canine Purkinje fiber by contrast medium.

Cardiac toxicity of angiographic contrast medium has been documented at the cellular level by using the methods of micro-electrode electrophysiology. Canine Purkinje fibers exposed to contrast medium exhibit a "slow response." The increased automaticity and slowed conduction inherent in this "slow response" may cause the serious arrhythmias and other adverse effects recorded by electrocardiograms during coronary angiography. Hyperosmolarity plays only a minor role in the observed cellular toxicity. The unphysiologic concentrations of sodium, potassium, and calcium in the tested contrast medium were not responsible for the changes observed. Toxicity is probably an inherent chemical property of iodinated diatrizoate or meglumine ions.

The pharmaco-kinetics of angiographic contrast media with special reference to the extravascular space. Experimental studies on dogs. III. Is there an entero-hepatic circulation of angiographic contrast media? A discussion summarising the results of the entire studies (author's transl)

The presence of an entero hepatic circulation of angiographic contrast media has been demonstrated, but quantitatively it is of little importance. About 1/2% of the contrast reaching the gut in the bile is reabsorbed and after being carried through the portal vein to the liver is re-excreted in the bile. Most of the contrastcontaining bile reaching the small bowel is excreted in the faeces; nearly all of the contrast absorbed from the colon is carried through the portal vein to the liver and after reaching the circulation is excreted by the kidneys.

The pharmaco-kinetics of angiographic contrast media, with special reference to the extra-vascular space. An experimental study on dogs. Paper II. Pharmaco-kinetics of an angiographic contrast medium used for selective angiography (author's transl)

Basic studies were carried out on experimental animals in order to investigate the pharmaco-kinetics of angiographic contrast media when used in various ways. Injections were carried out through angiographic catheters in a "physiological angiographic" manner. Measurements obtained by using radioactive compounds have shown that the distribution and excretion of the contrast medium are independent of the site of injection. The kinetics of the contrast within an organ do not differ, whether it is injected selectively or not. The results of all the experiments will be discussed at the conclusion of the third paper.

Arteriographic bleeding: a new sign.

A new sign of arteriographic bleeding, diastolic clearance of angiographic contrast medium selectively from the bleeding vessel, is described. The use of this sign must be confined to rapidly bleeding end-vessel distributions or when nonopacified collateral circulation is not a consideration. It should not be confused with the normal washout of contrast substance in areas of multiple parent vessel collateral circulation where intermittent opacification is a normal feature.

Mechanism of the effect of coronary artery stenosis on coronary flow in the dog

The hemodynamic mechanism of the effect of coronary artery stenosis on coronary flow was studied in the circumflex artery of 10 open-chest dogs by simultaneously measuring coronary flow, aortic pressure, and coronary artery pressure distal to an adjustable constrictor; while the distal coronary bed was intermittently maximally vasodilated by intracoronary injections of angiographic contrast media (Hypaque-M, 75 per cent). For each stenosis, the pressure gradient across the stenosis varied directly with the flow through the stenosis (r = 0.99), the slope of the regression indicating the severity of the stenosis. An important observation was that this regression line did not intercept the flow axis at zero flow, but at a positive flow, meaning that for a given regression line slope the pressure gradient was much less than expected. At rest, distal bed resistance decreased as progressive stenosis lowered the distal bed pressure, maintaining flow at control level until the distal bed pressure dropped below 60 mm. Hg. However, at maximum hyperemia, distal bed resistance was at a fixed minimum value such that flow was directly proportional to distal bed pressure. Hence, progressive stenosis decreased the ratio of hyperemic to resting flow by: (1) causing the vasodilatory reserve to be used to maintain resting flow, decreasing that available for hyperemia, and (2) dropping the distal bed pressure relatively more for smaller increases in flow. This study provides a hemodynamic explanation for the known fact that progressive stenosis initially limits the maximum hyperemic flow, and only after this flow is decreased almost to resting level, does resting flow fall.

Effect of angiographic contrast media at the cellular level in the brain: hypertonic vs. chemical action.

EFFECT OF ANGIOGRAPHIC CONTRAST MEDIA AT THE CELLULAR LEVEL IN THE BRAIN: HYPERTONIC VS. CHEMICAL ACTIONROBERT L. WALDRON, II, M.D., RICHARD B. BRIDENBAUGH, M.D. and EDWARD W. DEMPSEY, PH.D.Audio Available | Share

Effects of angiographic contrast media on regional cerebral blood flow and haemodynamics in man

In 33 human subjects with a sound circulatory system regional cerebral blood flow changes, following intracarotid injection of sodium methylglucamine diatrizoate (Angiografin, Urografin 76%) during cerebral angiography, were investigated. Angiografin®, at the start of recording 1 and 3 min after intracarotid injection, caused an increase of rCBF of 15.7% and 7.8% respectively. Urografin®, 3 min after completion of intracarotid injection, brought about an increase of rCBF of 23.0%. Under the action of both X-ray radiopaque materials at the start of rCBF-measurement, 5 and 8 min after completed intracarotid injection, there no longer was a significant difference from the resting values. Changes in haemodynamics (blood pressure, pulse rate) during carotid cerebral angiography with sodium-methylglucamine diatrizoate (Angiografin, Urografin 76%) were not observed in this study.

Effects of angiographic contrast medium on left ventricular function in coronary artery disease: Comparison with static and dynamic exercise

To evaluate several types of cardiovascular stress tests adaptable to the cardiac catheterization laboratory, modified ventricular function curves were constructed in 60 selected patients with a chest pain syndrome by plotting left ventricular stroke work index (SWI) against left ventricular end-diastolic pressure (EDP). After infusion of angiographic contrast medium, all normal control subjects exhibited an ascending ventricular function curve (λ[ΔSWI/ΔEDP]>0.1). Nine of the 10 patients with coronary artery disease and abnormal resting dynamics had a flat or depressed ventricular function curve. Twenty-six of the 37 patients with coronary artery disease and normal resting dynamics also had a depressed ventricular function curve. Nine normal subjects, when challenged by both static and dynamic exercise, exhibited an ascending ventricular function curve similar to the response to angiographic contrast medium. When 21 patients with coronary artery disease and normal dynamics underwent stress, flat or depressed ventricular function curves were seen in 71 percent of patients after infusion of angiographic contrast medium, 48 percent of the patients after static exercise, and 38 percent of patients after dynamic exercise. No patient with a normal response to the contrast medium had an abnormal response to either form of submaximal exercise. Thus, the combined hypervolemic and myocardial depressant effects of angiographic contrast medium serve as a convenient and reliable intervention to elicit left ventricular dysfunction in patients with coronary artery disease and normal ventricular function at rest. To evaluate several types of cardiovascular stress tests adaptable to the cardiac catheterization laboratory, modified ventricular function curves were constructed in 60 selected patients with a chest pain syndrome by plotting left ventricular stroke work index (SWI) against left ventricular end-diastolic pressure (EDP). After infusion of angiographic contrast medium, all normal control subjects exhibited an ascending ventricular function curve (λ[ΔSWI/ΔEDP]>0.1). Nine of the 10 patients with coronary artery disease and abnormal resting dynamics had a flat or depressed ventricular function curve. Twenty-six of the 37 patients with coronary artery disease and normal resting dynamics also had a depressed ventricular function curve. Nine normal subjects, when challenged by both static and dynamic exercise, exhibited an ascending ventricular function curve similar to the response to angiographic contrast medium. When 21 patients with coronary artery disease and normal dynamics underwent stress, flat or depressed ventricular function curves were seen in 71 percent of patients after infusion of angiographic contrast medium, 48 percent of the patients after static exercise, and 38 percent of patients after dynamic exercise. No patient with a normal response to the contrast medium had an abnormal response to either form of submaximal exercise. Thus, the combined hypervolemic and myocardial depressant effects of angiographic contrast medium serve as a convenient and reliable intervention to elicit left ventricular dysfunction in patients with coronary artery disease and normal ventricular function at rest.

The effect of angiographic contrast media at the cellular level in the brain.

Repeated carotid artery injections of contrast media were performed in cats and cerebral biopsy samples obtained for electron microscopy. Evidence suggests that there are two methods by which the blood-brain barrier may break down with repeated angiography: (a) alteration of the tight junctions between capillary endothelial cells in the brain, allowing passage of matter through these junctions, and (b) transport across the endothelial cells by pinocytosis.

Alterations at the Cellular Level in the Brain Following Repeated Angiography: Protective Effect of Corticosteroids

Waldron, Robert L. II, MD; Bridenbaugh, Richard B. MD; Dempsey, Edward W. PhD Author Information

The effect of haemodynamic changes induced by angiographic contrast media on aortic regurgitation in the sedated dog.

Summary: Angiographic contrast media induce changes in cardiac and circulatory function. Their effect on the extent of aortic regurgitation in closed-chest sedated dogs was studied. Ascending aortic flow was measured by an electromagnetic transducer, implanted five to ten days earlier when aortic regurgitation had been produced. Sodium iothalamate 80% or 76% sodium methylglucamine diatrizoate (0.5 ml/kg body weight) were injected into the left ventricle. Seconds later there was a decrease in peak rate of left ventricular pressure rise and inconsistent elevation of trans-mural left ventricular end-diastolic pressure but no change in aortic regurgitation. Twelve to sixteen seconds after injection significant hypotension, due to decreased systemic vascular resistance, appeared and was usually accompanied by tachycardia. Diastolic regurgitant volume fell 48‡ 13 (SD)% (p < 0.001) but total stroke volume fell only 10%, regurgitant fraction decreasing 43‡ 11% (p < 0.001). Duration of regurgitation per minute fell, but not consistently (8‡ 11%; p < 0.1), and most of the decrease in regurgitation was due to a fall in regurgitant flow rate early in diastole (36‡ 16%p < 0.001) associated with decrease in aortoventricular pressure difference. Effective cardiac output increased 84‡ 50%. Hypotension and tachycardia disappeared by one minute; then persistent increase in forward flow parameters became associated with variable increase in regurgitation. Left ventricular end-diastolic pressure became elevated. The early changes are consistent with mild depression of left ventricular contractility, but there was no change in aortic regurgitation. Thereafter, hypotension, with or without prominent tachycardia, led to decrease in aortic regurgitation. Subsequently, regurgitation tended to increase above the control value, other concomitant changes being consistent with expansion of intravascular volume. Changes induced in aortic regurgitation by angiographic contrast media are importantly time dependent and secondary to other haemodynamic effects.

Detection of intracardiac shunts with radionuclide imaging

Cardiac catheterization for the performance of contrast angiography is accepted presently as method for the demonstration of intracardiac shunts in children and adults. The procedure is an essential part of the presurgical workup. Cardiac angiography requires a skilled team of pediatric cardiologists, radiologists, technical personnel, and excellent equipment; consequently, it is a time consuming and expensive procedure. In addition, cardiac catheterization is not without risk, and is particularly hazardous in the cyanotic newborn. The use of the angiographic contrast medium provides additional hazards. Prior to the development of the Anger camera, the precordial radiocardiogram was the major nuclear medicine technique used for the diagnosis of intracardiac shunts. Scintillation probes, well counters, strip-chart recorders, and, occasionally, cardiac catheterization were required to perform the radiocardiogram. It was a time consuming procedure. Pulmonary dilution curves were also used for the diagnosis of intracardiac shunts. Although various types of intracardiac shunts could be detected with these two types of dilution curves, no satisfactory method of accurate shunt quantitation was developed. After adequate experience was obtained with the Anger camera, radionuclide angiocardiography became a major investigative technique in nuclear medicine for the diagnosis of intracardiac shunts. The technique has several potential technical and clinical advantages over heart catheterization and contrast angiography. These advantages are (1) there is no need for withdrawal of arterial or venous blood, (2) it can be performed simply and quickly, (3) it requires only an intravenous bolus injection, (4) it is reliable in all age groups, (5) it may be performed in patients who are sensitive to cardiographic agents or in those too ill to undergo heart catheterization and contrast angiography, and (6) its risks to the patient are negligible. Characteristic nuclide flow patterns and images have been demonstrated in patients with left-to-right and right-to-left intracardiac shunts. Techniques for the quantitation of shunts employing nuclide angiocardiography are being developed.

Effects of angiographic contrast medium on left ventricular function in coronary artery disease. Comparison with static and dynamic exercise

Effects of angiographic contrast medium on left ventricular function in coronary artery disease. Comparison with static and dynamic exercise

Polymeric Additives to Angiographic Contrast Medium: Development of an Adhesive Contrast Material

An angiographic contrast medium which would adhere to the endothelium of the cardiovascular system would increase the duration of the radiographic information while smaller doses injected at lower rates could be employed. Agar, gum acacia, polyvinylpyrrolidone (PVP), high and low molecular weight dextran, serum albumi, and gelatin were considered as additives to 60% meglumine diatrizoate. Agar and gum acacia did not yield solutions suitable for testing. The other solutions were tested for adhesiveness, and their electrical conductivity, as a possible toxicologic parameter, was measured in equiviscous solutions of 60-65 cps. Low molecular weight dextran and serum albumin did not adhere. For solutions containing high molecular weight dextran, PVP, and gelatin, the washout times were significantly increased relative to 60% meglumine diatrizoate. Serum albumin lowered the conductivity of 60% meglumine diatrizoate by 30%, low molecular weight dextran by 50%, PVP by 3%, high molecular weight dextran by 19%, and gelatin by 32%. Gelatin was considered the additive of choice since it conferred adhesiveness and it is non-toxic and bio-degradable. A type which was originally developed as a plasma expander was deionized, bleached, and depyrogenized. It was combined with diatrizoic acid in an attempt to form a stable compound. Results of infrared spectrography, Sephadex chromatography, and equilibrium dialysis proved that no compound or complex was formed. It was found that a solution of 6% or 8% gelatin in 60% meglumine diatrizoate provided a stable medium which upon injection into the vessel adhered to its walls for a period of several seconds.

Polymeric Additives to Angiographic Contrast Medium: Development of an Adhesive Contrast Material

Polymeric Additives to Angiographic Contrast Medium: Development of an Adhesive Contrast Material

Polymeric Additives to the Angiographic Contrast Media

Polymeric Additives to the Angiographic Contrast Media

Effect of Dextran Infusion and State of Hydration on Cerebral Toxicity of Angiographic Contrast Media

Wayne County General Hospital, Eloise, Michigan, and the University of Michigan, Ann Arbor, Michigan

Comparison of a sodium methylglucamine diatrizoate contrast medium of minimal sodium content with a pure methylglucamine diatrizoate preparation.

Injections into the carotid arteries of dogs and rabbits were used to estimate the toxicities of two cerebral angiographic contrast media. The two diatrizoate media differed only in their cation composition. Based on the changes produced in heart rate and blood pressure in dogs, the agent with methylglucamine as its sole cation was better tolerated than the agent which contained a small amount of sodium with the methylglucamine.

Sequential effect of angiographic contrast agent on canine renal and systemic hemodynamics

The prolonged effects of angiographic contrast media on systemic hemodynamics, renal function, and solute excretion were compared to saline and mannitol in dogs lightly anesthetized with pentobarbital. Measurements of hemodynamic and renal function were made at intervals from one half hour before to one hour after rapid left ventricular injection. The progressive decline in cardiac output and renal plasma flow, following iothalamate reflected diuresis induced volume depletion since these effects were reversed by replacing urine volume. This latter maneuver did not modify the iothalamate effect on renal solute excretion. Although the rate and pattern of urinary excretion of iothalamate- 131I paralleled mannitol, the magnitude of the iothalamate diuresis significantly exceeded that induced by mannitol. The augmented iothalamate diuresis resulted from an increased urinary content of sodium chloride as confirmed by a significant decrease in tubular chloride reabsorption. Mannitol caused an increased renal plasma flow and a reduced renal vascular resistance, while iothalamate effects were opposite. The effect of iothalamate on renal electrolyte reabsorption may represent a direct effect on renal-tubular sodium transport.

Trends in preparation of new angiographic contrast media with special emphasis on polymeric derivatives.

Professor of Radiology, Neurological Institute, Columbia–Presbyterian Medical Center, New York, N. Y.