Evaluation of high viscosity contrast media in canine selective coronary arteriography.

A special high viscosity preparation of water soluble radiopaque contrast media was explored in animals for its suitability in selective coronary angiography. The high viscosity required power injection to accomplish adequate filling during selective coronary arteriography. The anticipated angiographic advantages, such as prolonged visualization and coating of the vascular walls, were marginal. Comparison with conventional preparations of the same contrast agent suggests that the high viscosity itself exerts some protective effect with regard to the immediate side effects on the electrocardiogram and mechanical function of the myocardium. However, the high viscosity preparation induced electrocardiographic signs compatible with myocardial ischemia not usually seen to follow the injection of conventional contrast agents. These were followed by mechanical heart failure or ventricular fibrillation resulting in death of 6 of the 10 experimental animals. It was concluded that high viscosity contrast media preparations are unsuitable for use in clinical selective coronary arteriography as presently practiced.     

Pressurized contrast delivery for coronary arteriography

A system is described for eliminating negative pressure source of air bubbles within a closed-circuit arrangement for dye delivery in coronary angiography. Replacing the usual manual pressure created by an aspirating syringe, this system pressurizes the reservoir bottle by means of a cuffed bag, double-lumen, one-way piercing spike and a 0.2 μm filter.     

Mechanism of ECG changes and arrhythmogenic properties of low osmolality contrast media during coronary arteriography in dog

STUDY OBJECTIVE--The aim of the study was to investigate the mechanisms behind ECG changes and ventricular arrhythmias during coronary arteriography. DESIGN--Transmembrane action potentials were recorded from isolated heart muscle preparations superfused with contrast media. Conductivity of plasma diluted with contrast media was determined in vitro. Epicardial ECG recordings were made during coronary arteriography. SUBJECTS--Epicardial ECG recordings were made in eight mongrel dogs of either sex, weight 14-22 kg. Atrial appendages were excised from the same dogs and used for heart muscle preparation studies. MEASUREMENTS and MAIN RESULTS--Iohexol and ioxaglate affected the action potentials similarly: resting potential, amplitude, rate of depolarisation, and action potential duration increased; effective refractory period decreased. Both contrast media reduced plasma conductivity. During coronary arteriography both media increased R wave amplitude, depressed ST segment, and prolonged QT time on epicardial ECG. CONCLUSIONS--ST segment deviation on ECG reflects hyperpolarization and increased amplitude of action potential rather than depolarisation consistent with ischaemia. Increased rate of depolarisation and amplitude of action potential together with reduced conductivity after contrast media may explain increased amplitude of QRS voltage on ECG. Observed regional changes in depolarisation, repolarisation, and refractoriness may be important in the genesis of ventricular arrhythmias.     

Effect of viscosity and iodine concentration of nonionic radiographic contrast media on coronary arteriography in patients.

To assess the influence of viscosity and iodine concentration, three matched and standardized left coronary arteriograms were obtained in 20 patients using iopamidol (Isovue-370), ioversol (Optiray-320), and iohexol (Omnipaque-350). The order of contrast media was randomized and the administration of contrast was double-blinded. Quantitative densitometric angiographic evaluation of the coronary angiograms was performed in addition to independent operator qualitative assessment. The injection volume of iopamidol (5.4 +/- 1.0 ml) was slightly but significantly less than that of ioversol and iohexol (5.6 +/- 1.0 ml, 5.7 +/- 1.0 ml, both p less than 0.05). The calculated iodine concentration was also lower for ioversol (1.7 +/- 0.32 gm) than for iopamidol (1.98 +/- 0.35 gm) and iohexhol (1.9 +/- 0.35 gm, both p less than 0.05). There were significantly lower contrast syringe injection pressures for ioversol (6.6 +/- 0.8 atm) than for iopamidol (7.5 +/- 0.9 atm) and iohexol (7.2 +/- 1.1 atm, both p less than 0.05). The quantitative densitometric analysis failed to demonstrate significant differences among the contrast media with respect to image density parameters for any individual agent. All coronary angiograms were deemed of diagnostic quality. The data in this study indicated that although differences in iodine concentration exist among the three agents, operator compensation with more rapid contrast delivery (higher volume) and lower viscosity (lower injection pressure) produced equivalent image opacification during coronary angiography. Given the same incidence of adverse hemodynamic and clinical effects, selection of a low viscosity media theoretically provides an advantage during procedures using small diameter catheters or interventional procedures requiring contrast visualization through reduced catheter lumina.     

Selective coronary arteriography: A clinical comparison of two contrast agents

The radiopacity and complications of meglumine iothalamate 52% and sodium iothalamate 26% (Vascoray®) were compared with those of meglumine diatrizoate 66% and sodium diatrizoate 10% (Renografin®-76) in 2258 patients with and without cardiac disease. There was no difference in radiopacity and the type and incidence of adverse reactions were similar, but the frequency was significantly higher (p < 0.05) with Vascoray® in patients with constrictive pericarditis, dissecting aortic aneurysm, and primary pulmonary hypertension. The difference in the frequency of hypotension, sinus bradycardia, and transient asystole in the Renografin®-76 and Vascoray® groups was statistically significant. Ventricular arrhythmias occurred in 6% of the patients with primary myocardial disease compared to an average of 0.7% in those without this cardiac abnormality (p < 0.01), but there was no significant difference in the frequency in the two contrast agent groups. All reactions were treated and the studies were performed without mortality. Results of this study show that iothalamate formulation with sodium to meglumine ratio of 1:2 containing 410 mEq/L of sodium (Vascoray®) is suitable and safe for clinical use for roentgenographic studies of the heart, and coronary artery circulation.     

Ventricular fibrillation during coronary angiography: reduced incidence in man with contrast media lacking calcium binding additives

The intracoronary injection of contrast media during coronary angiography occasionally results in ventricular fibrillation. Experimental studies have implicated the calcium sequestering agents, sodium citrate and EDTA in Renografin 76 (RG76), as contributing to this complication. Angiovist 370 (AV370) is a contrast medium similar to RG76 except that it contains disodium calcium EDTA instead of EDTA and sodium citrate. To determine if contrast media lacking sodium citrate and EDTA will result in a lower incidence of ventricular fibrillation in man, this investigation compared the incidence of contrast media-induced ventricular fibrillation in patients undergoing coronary angiography with RG76 to that with AV370. Group A consisted of 2,500 consecutive patients undergoing coronary angiography with RG76 and group B consisted of 2,000 subsequent consecutive patients in whom AV370 was employed as the contrast medium. There was no significant difference between groups A and B with respect to the volume of contrast media used per patient (153 +/- 49 ml vs 154 +/- 45ml), age (58.4 +/- 10 vs 58.6 +/- 10 years), sex (70% male vs 70% male), ejection fraction (59 +/- 17 vs 60 +/- 20), history of mitral valve disease (5.8% vs 7.1%), history of aortic valve disease (6.7% vs 6.5%), prior coronary artery bypass graft surgery (6.6% vs 7.3%), or extent of coronary artery disease. Fifteen episodes of contrast media-induced ventricular fibrillation occurred in group A (incidence 0.6%) whereas two episodes occurred in group B (incidence 0.1%) (p less than 0.02). Each patient was successfully defibrillated and no adverse sequelae resulted. Thus the present investigation suggests that the incidence of ventricular fibrillation during coronary angiography can be significantly decreased by using contrast media lacking sodium citrate and EDTA.     

高浓度对比剂在冠状动脉多排螺旋CT的应用

目的:探讨高浓度对比剂在冠状动脉多排螺旋CT(multidetector-row computed tomographicangiography,MDCTA)的应用效果。方法:冠心病筛查者60例随机分为两组,每组30例;分别采用400mg I/mL和350 mg I/mL浓度的对比剂进行MDCTA检查,在流率为3.7 mL/s和对比剂总量,2组间差异无统计学意义,并计算两组的心功能指标,对冠状动脉主干、主要分支血管近段及主动脉血管强化程度进行比较,对重建血管清晰度进行评价。结果:两组心功能指标差异无统计学意义,400 mg I/mL组血管强化程度优于350 mg I/mL组(P<0.05),两组差异具有统计学意义,重建血管清晰度各组间差异无统计学意义。结论:在较低流速下,高浓度对比剂400 mgI/mL浓度较350 mgI/mL浓度对比剂图像质量好,冠状动脉及主动脉血管强化程度高,重建血管清晰度无差异。     

Iopamidol: a new contrast medium in coronary angiography: Comparison, on electrophysiological changes in man, with a commonly used contrast medium

In 30 patients undergoing coronary angiography the effects oflopamidol on sinus node activity, atrioventricular and intraventricularconduction were evaluated using His Bundle recordings, and comparedto the effects produced by Diathzoate. Diatrizoate resulted in an increase in sinus cycle length andprolonged AV nodal conduction, resulting in second degree AV block in two patients, lopamidol had significantly less effecton sinus cycle (P<0.01) and AV nodal conduction (P<0.01).Neither contrast media affected intraventricular conduction.No difference was noted in the imaging power of the two contrastmedia. It is suggested that non-ionic, low osmotic contrast media suchas lopamidol will result in increased patient safety duringcoronary angiography without loss of imaging power.     

Left ventricular diastolic impairment during coronary arteriography with a non-ionic contrast medium

AIM: The aim of this study was to assess the influence of coronary arteriography with the use of a non-ionic low molecular monomer (iopromide) on left ventricular function. METHODS: Fifty consecutive patients with coronary artery disease (CAD) and normal left ventricular ejection fraction were studied by coronary arteriography for a stable or unstable coronary syndrome by using iopromide. They were divided into 2 groups: group 1, patients with one vessel disease; group 2, patients with multiple vessel disease. A >50% reduction of the lumen diameter by on-line quantitative angiography was considered a significant coronary stenosis. Coronary arteriography was performed by hand injection of 5 ml of iopromide avoiding the use of nitrates during the procedure. Doppler echocardiography monitoring was performed immediately before the coronary arteriography and at the end of the last coronary injection. The following parameter were recorded: E peak velocity (E) (cm/s), A peak velocity (A) (cm/s), E/A ratio, E deceleration time (EDT) (ms), isovolumic relaxation time (IRT) (ms), and left ventricular ejection fraction (EF) (%). RESULTS: No complications were observed during the procedures. A mean amount of 40+/-8 ml of iopromide was used. No significant variation of heart rate and arterial pressure was shown during coronary arteriography. No changes were observed either for E, A, E/A ratio or for left ventricular EF in any group of patients. A significant increase of EDT and IRT in comparison with baseline values was documented only in group 2 (from 140+/-77 to 199+/-44 and from 98+/-33 to 144+/-44, p<0.01), returning to baseline values after 10+/-3 minutes. A positive correlation was observed between EDT and IRT shift from baseline values (r=0.77; p<0.01). CONCLUSION: In conclusion, iopromide temporarily impairs left ventricular diastolic dynamics during selective coronary angiography, but only in patients with multivessel CAD.     

In vivo effects of contrast media on coronary thrombolysis

Objectives. The aim of the present study was to evaluate the influence of radiographic contrast media (CM) on alteplase-induced coronary thrombolysis.Background. Contrast media inhibit fibrinolysis in vitro and interact with endothelial cells, platelets and the coagulation system. The in vivo effects of CM on thrombolysis are not known.Methods. Occlusive coronary artery thrombosis was induced in 4 groups of 10 dogs by the copper coil technique. After 70 min of occlusion the dogs were randomized to intracoronary injection of 2 ml kg⁻¹of either saline, a low-osmolar ionic CM (ioxaglate), a low-osmolar nonionic CM (iohexol) or a high-osmolar ionic CM (amidotrizoate). Thrombolysis with alteplase and co-therapy with aspirin and heparin was initiated after 90 min of occlusion. The coronary artery flow was monitored with an electromagnetic flowmeter throughout the experiment.Results. Iohexol and amidotrizoate, but not ioxaglate, were associated with longer reperfusion delays (time to optimal reperfusion: 67 ± 48 min and 65 ± 49 min, respectively, vs. 21 ± 11 min after placebo; p < 0.05) and shorter periods of coronary perfusion (optimal perfusion time: 21 ± 26 min and 21 ± 28 min, respectively, vs. 58 ± 40 min after placebo; p < 0.05). No significant differences were observed between groups with regard to activated partial thromboplastin times, circulating thrombin-antithrombin III complex concentrations and fibrinogen.Conclusions. In this animal model administration of iohexol and amidotrizoate before thrombolysis significantly delayed reperfusion. This interaction should be considered in the design of clinical trials of thrombolytic therapy that evaluate coronary artery patency and in patients receiving local infusions of fibrinolytic agents.     

Effect of selective coronary arteriography on left ventricular volumes and ejection fraction in man

This study was performed to assess the influence of selective coronary arteriography on left ventricular volumes and ejection fraction in man. In 30 patients with assorted cardiac diseases, left ventricular end-diastolic and end-systolic volumes and ejection fraction were quantitated immediately before and after selective coronary arteriography. In 19 patients (Group A), contrast left ventriculography was performed immediately before and after selective coronary arteriography. In the remaining 11 patients (Group B), multigated equilibrium blood pool imaging was performed just before and after coronary arteriography. In both groups, mean systemic arterial pressure and heart rate did not change from just before the first to immediately before the second assessment of left ventricular volumes and ejection fraction, but left ventricular end-diastolic pressure increased. End-diastolic and end-systolic volume indexes, and ejection fraction did not change from just before to immediately after selective coronary arteriography. Therefore, selective coronary arteriography (1) consistently causes an increase in left ventricular end-diastolic pressure but (2) exerts no effect on left ventricular volumes and ejection fraction, even in patients with severely compromised left ventricular function.