Sinus slowing produced by intracoronary arterial injections of hyperosmotic solutions in man

Comparison of meglumine sodium diatrizoate, iopamidol, and iohexol for coronary angiography and ventriculography

Meglumine sodium diatrizoate (Urografin), iopamidol, and iohexol were compared in a double-blind, randomized study of 287 patients undergoing elective cardiac angiography. Ninety-six patients received Urografin, 98 received iopamidol, and 92 received iohexol. The groups were similar in all respects. Variables measured before and after contrast injection were left ventricular end-diastolic pressure (LVEDP), left ventricular systolic pressure (LVSP), systolic arterial pressure (SAP), RR, PR, and QTc intervals, QRS duration, ST segment change greater than 2 mm, arrhythmias, and symptoms. The adequacy of coronary and ventricular opacification was assessed by two experienced observers. Following left ventriculography, small rises in LVEDP occurred with iopamidol and iohexol (mean +/- SD: 18 +/- 7 to 21 +/- 7 mmHg) and a moderate fall in LVSP with Urografin (150 +/- 32 to 133 +/- 32 mmHg). Following coronary angiography there was a progressive fall in SAP (130 +/- 26 to 117 +/- 30 mmHg) and prolongation of RR intervals (900 +/- 138 to 1,266 +/- 692 msec) and QTc (440 +/- 61 to 471 +/- 73 msec) and QRS duration (87 +/- 25 to 100 +/- 27 msec) with Urografin. There was a small fall in SAP with iopamidol (138 +/- 25 to 128 +/- 27 mmHg) and prolongation of QRS duration with iohexol (85 +/- 29 to 90 +/- 24 msec). Other parameters were not significantly affected. Frequent bradyarrhythmias (sinus pause 14.5%, asystole 6%) and ST segment depression occurred following Urografin. Urografin was less well tolerated, with 10% of patients experiencing severe nausea or vomiting and 30% of patients experiencing extreme heat sensation. Differences between iohexol and iopamidol were minor.(ABSTRACT TRUNCATED AT 250 WORDS)

A multicenter randomized trial of ionic (ioxaglate) and nonionic (iopamidol) low-osmolality contrast agents in cardiac angiography

A multicentered double-blind randomized study was performed comparing the electrocardiographic and hemodynamic changes induced by two new low osmolar contrast agents used for cardiac angiography. The low osmolar ionic (ioxaglate) contrast agent was compared with a low osmolar nonionic (iopamidol) contrast agent in 150 patients with angina pectoris undergoing angiography. Systolic blood pressure, left ventricular end-diastolic pressure, heart rate, and QT interval were measured just before and for 90 s following the left ventricular angiography and selective coronary angiography. Each group was also evaluated for adverse events and quality of radiographic images. Following left ventricular angiography, the systolic blood pressure dropped slightly in both groups with a greater decrease seen in the iopamidol group at 5 s (p less than 0.05). After selective right and left coronary angiography, systolic blood pressure decreased transiently and equally in both treatment groups. The left ventricular end-diastolic pressure increased after the ventriculogram in both groups (15.9 +/- 6.3 to 18.9 +/- 8.6 mmHg in the ioxaglate group and 16.1 +/- 6.7 to 20.1 +/- 7.8 mmHg in the iopamidol group), the change being significant only in the iopamidol group (p less than 0.05). Heart rate increased slightly but significantly in the ioxaglate-treated patients following left ventricular angiography (71.4 +/- 15.2 to 74.4 +/- 13.7 beats/min) (p less than 0.01). QT interval transiently increased following left ventriculography with ioxaglate (407 +/- 59.5 to 420 +/- 58.3 ms) (p less than 0.05) compared with iopamidol.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparative effects of ionic and nonionic contrast materials on indexes of isovolumic contraction and relaxation in humans

The effects of contrast media on left ventricular (LV) relaxation as assessed by the time constant of isovolumic relaxation have not previously been studied. A new nonionic contrast agent (iohexol) has been shown to have fewer deleterious effects than standard ionic agents. Nineteen patients received iohexol and sodium meglumine diatrizoate (Renografin-76) in a double-blind, crossover study during left and right coronary arteriography and with simultaneous high-fidelity micromanometer measurements of LV pressure. Neither agent induced significant changes in LV end-diastolic pressure after right or left coronary arteriography. After right coronary arteriography, neither agent produced significant deterioration of peak positive dP/dt or (dP/dt)/DP40 (dP/dt at a developed pressure of 40 mm Hg). However, after right coronary arteriography both agents caused a transient deterioration in peak negative dP/dt and the time constant of isovolumic relaxation (p less than 0.05 at 20 seconds after arteriography). After left coronary arteriography, sodium meglumine diatrizoate induced deterioration of systemic blood pressure (p less than 0.05), peak positive dP/dt (p less than 0.01), (dP/dt)/DP40 (p less than 0.05), peak negative dP/dt (p less than 0.01) and the relaxation time constant (p less than 0.01). These effects were not induced by iohexol. Thus, nonionic contrast media exert negligible alterations on LV function when used for coronary arteriography. The findings are of potential clinical importance in view of the large number of patients with depressed LV function who undergo coronary arteriography.

Effects of angiographic contrast medium on left ventricular function: evaluation by contrast angiography and radionuclide angiography

The purpose of this study was to evaluate the effect of angiographic contrast medium on left ventricular (LV) function in 26 patients undergoing diagnostic cardiac catheterization. Beat-by-beat analysis during contrast ventriculography showed that the ejection fraction (EF) was lower in the last beats than in the first beats (P less than .02). Radionuclide angiograms were obtained the day before, as well as 15 to 65 minutes after catheterization, which included contrast ventriculography and coronary anteriography. The EF by radionuclide angiography was lower after catheterization than before (43 +/- 14% vs 47 +/- 17%, P less than .01). The EF decreased by greater than or equal to 5% in 11 of the 26 patients (42%) after catheterization. The decrease in EF in some patients was observed up to 65 minutes after catheterization and was not associated with symptoms or ST-T changes. The EF decreased in only one of nine patients who received nitroglycerin during catheterization, whereas it decreased in 10 of 17 patients who did not receive nitroglycerin (P less than .05). The EF decreased in 9 of 14 patients (64%) who had normal resting LV function, whereas it decreased in only 2 of 12 patients (17%) who had abnormal resting function (P less than .05). Thus, contrast material may depress LV function up to 1 hr and is more frequent in patients with normal resting EF. The use of nitroglycerin during catheterization may mask this effect.

Acute changes in infranodal conduction time following left ventriculography and sublingual nitroglycerin administration in man

During diagnostic cardiac catheterization for the evaluation of chest pain, His bundle electrograms were obtained in 32 male patients before and 2 to 5 minutes after each of two interventions known to acutely affect left ventricular volume and left ventricular end-diastolic pressure (the injection of 40 to 60 cc of contrast medium during left ventriculography and the administration of 0.4 mg of sublingual nitroglycerin). Changes in left ventricular end-diastolic pressure (18 +/- 6 vs 30 +/- 7 mm Hg, p less than 0.001 following ventriculography and 32 +/- 8 vs 19 +/- 8 mm Hg, p less than 0.005 following nitroglycerin administration) were accompanied by parallel alterations in HQ (48 +/- 8 vs 54 +/- 10 msec, p less than 0.005 following ventriculography and 57 +/- 10 vs 53 +/- msec, p less than 0.005 following nitroglycerin administration), but there were no significant changes in atrioventricular (AV) nodal conduction (AH). Significantly greater changes in HQ were seen in patients with triple-vessel coronary artery disease than in the remainder of the population, although there was clinical and/or ECG evidence of ischemia in only one patient. We conclude that factors other than progression of intrinsic conduction system disease may affect infranodal conduction. HQ should be interpreted cautiously in situations with rapidly changing hemodynamics, especially in patients with severe coronary artery disease.

Hemodynamic and electrocardiographic effects in man of a new nonionic contrast agent (iohexol): advantages over standard ionic agents

Iohexol is a new, nonionic contrast material that has been shown in animal studies to hold great promise as an agent for coronary arteriography and ventriculography with fewer adverse hemodynamic effects than standard ionic media. At present, it has not been studied systematically in man. Fifty patients referred for elective cardiac catheterization were randomized to receive either iohexol or meglumine sodium diatrizoate (Renografin-76). Both operator and patient were blinded as to which agent was being used. Hemodynamic variables measured were pulmonary artery wedge pressure and systemic blood pressure. In addition, the following electrocardiographic indexes were evaluated: S-T segment shifts, changes in Q-T interval, changes in T-wave amplitude, and changes in heart rate. These variables were measured after left ventriculography and after both left and right coronary arteriography. Both iohexol and sodium meglumine diatrizoate produced small transient elevations in pulmonary artery wedge pressure. Systemic hypotension occurred with both agents but was more profound and longer-lasting with sodium meglumine diatrizoate. Iohexol injection resulted in no electrocardiographic changes, whereas sodium meglumine diatrizoate produced marked Q-T prolongation, as well as changes in T-wave amplitude and heart rate. Iohexol was well tolerated by the patients, and radiographic opacification was good to excellent in all cases. Thus, iohexol produces fewer deleterious hemodynamic and electrocardiographic changes than sodium meglumine diatrizoate when studied in a typical adult population requiring diagnostic cardiac catheterization. This favorable preliminary experience in man has potential widespread importance because of the large number of patients undergoing angiographic procedures.

Tolerability and usefulness of iohexol in cardioangiography. I. An open multicentre clinical trial

The first investigation of iohexol in human cardioangiography is presented. Slight subjective reactions as well as moderate and transient influence on hemodynamics and ECG parameters were recorded. Analysis of serum enzymes indicated no myocardial injury. Good or excellent films of the left ventricle, aortic root and coronary arteries were obtained.

Regional myocardial hemodynamic and metabolic effects of ionic and nonionic contrast media in normal and ischemic states

The effects of intracoronary injection of two nonionic contrast media (iohexol and metrizamide) on myocardial contraction and chemical composition of coronary sinus (CS) blood were compared with those caused by the standard ionic contrast material for coronary angiography, sodium meglumine diatrizoate (R76), in 14 anesthetized dogs. The effects of each agent on regional contractility were compared in the normal state and in the presence of a critical coronary artery stenosis. The three contrast media produced equivalent decreases in hematocrit and sodium (both NS), but R76 caused a greater increase in CS osmolality (p less than 0.02). R76 caused a significant decrease in CS potassium and ionized calcium (both p less than 0.001), but neither nonionic contrast medium caused a significant change in either potassium or calcium. In the normal state, R76 caused initial transient (less than 10 seconds) increases in both end-diastolic (p less than 0.006) and end-systolic segment length (p less than 0.02) and a decrease in rate of change of segment length (dL/dt) (p less than 0.002). The nonionic agents caused a mild increase in dL/dt (p less than 0.04) and a decrease in end-systolic segment length (p less than 0.03); both returned to control levels within 1 minute. In the presence of a stenosis, R76 caused a more severe and prolonged increase in end-diastolic and end-systolic segment lengths (p less than 0.03) and a decrease in dL/dt (p less than 0.002), which did not return to control within 2 minutes. The effects of the nonionic agents were similar in both normal and diseased states. We conclude that nonionic contrast media produce fewer alterations than ionic contrast media in coronary sinus blood chemistry and myocardial contractile state. The effect of ionic contrast media on regional contraction is accentuated in the presence of coronary artery stenosis.