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Biomedical subjects

P J Scanlon

Publications and source records attributed to P J Scanlon.

At least 55 records · Page 3Linked to original sources
PubMed1989

Placement of intra-aortic balloon pump allows definitive biliary surgery in patients with severe cardiac disease.

This study reviews the cases of 15 patients with severe cardiac disease treated with the intra-aortic balloon pump (IABP) to improve cardiac status so that they could undergo definitive cholecystectomy. The 14 men and one woman ranged in age from 49 to 74 years. Indications for cholecystectomy included acute cholecystitis in nine patients and chronic cholecystitis in six patients. All patients had prior myocardial infarction, and in two patients this had occurred within 2 months of operation. All patients were Goldman's Class IV. Eight had severe cardiomyopathy. Mean ventricular ejection fraction was 21% +/- 3%. Cardiac index was 2.2 +/- 0.2 L/m/m2, and pulmonary artery pressure (PAP) was 51 +/- 5/23 +/- 2 mm Hg. After IABP placement, pulmonary wedge pressure decreased in all patients, from 24 +/- 3 mm Hg to 16 +/- 2 mm Hg (p less than 0.01). PAP systolic pressure decreased to 38 +/- 3 mm Hg (p less than 0.01), and PAP diastolic pressure decreased to 18 +/- 2 mm Hg (p less than 0.05). All patients had cholecystectomy. Five patients had intraoperative cholangiography. One of these five patients had a common bile duct exploration, and another underwent cystgastrostomy. Two patients died postoperatively of arrhythmias. Thirteen patients are alive 3 months to 7 years after operation, without biliary symptoms. Three patients have had orthotopic heart transplants. We conclude that IABP significantly improves cardiac performance so that many patients who have severe cardiac disease can undergo definitive biliary surgery.

Aged↗
PubMed1989

Predictors of late acute orthotopic heart transplant rejection.

To identify predictors of late acute rejection after orthotopic heart transplantation (OHT), 53 patients who received transplants between March 1984 and March 1987 and who survived at least 1 year postoperatively were followed up for 402-1,151 days (mean, 841 days). Fourteen patients experienced 22 moderate or severe rejection episodes more than 1 year after OHT (LR); 39 were nonrejectors (NR). Twelve of 14 (86%) LR and only 14 of 39 (36%) NR had two or more moderate or severe rejection episodes within the first year after OHT (p less than 0.001). The LR had significantly higher numbers of infections more than 1 year after OHT (2.0 vs. 0.9; p less than 0.05). Nine of 22 (40%) late acute rejection episodes followed within 1 month of infection. Human leukocyte antigen reactivity before OHT, follow-up hemodynamics, length of survival, incidence of diabetes mellitus, coronary artery disease 1 year after OHT, mean cyclosporine levels, and mean daily prednisone doses were similar in LR and NR patients. We conclude that 1) OHT recipients with two or more moderate or severe rejection episodes in the first year after OHT are at higher risk of developing late acute rejection and may require closer long-term rejection surveillance and more aggressive maintenance immunosuppression and 2) the possible relation between infection and subsequent acute rejection episodes in OHT recipients requires further investigation.

Adult↗
PubMed1988

Safety and efficacy of esmolol for unstable angina pectoris.

Esmolol is a rapidly metabolized cardioselective beta-adrenergic blocker that provides steady state beta-adrenergic blockade when administered by continuous intravenous infusion. To determine the efficacy of esmolol in the management of unstable angina, 23 patients with known coronary artery disease, who averaged 3.7 +/- 2.7 daily episodes of chest pain at rest, were randomized to receive either a continuous infusion of esmolol (n = 12) or oral propranolol (n = 11), as an adjunct to concomitant antianginal therapy. Patients with systolic blood pressure less than 110 mm Hg, heart rate less than 60 beats/min or known contraindications to beta blockade were excluded. Esmolol was titrated in a step-wise fashion from 2 to 24 mg/min at 5-minute intervals up to a 30% reduction in heart rate and systolic blood pressure double-product. The propranolol dose was increased every 6 hours by 50 to 100% to achieve a similar reduction in heart rate and blood pressure. When compared with their 24-hour baseline periods, both groups achieved a significant reduction in episodes of chest pain, from 4.6 +/- 3.3 to 1.4 +/- 1.5 in the esmolol group (p less than 0.02) and 2.6 +/- 1.4 to 1.0 +/- 1.5 in the propranolol group (p less than 0.02) during the subsequent study period. The cardiac event rate and incidence of drug side effects were similar between the 2 groups; however, side effects seen with esmolol did not require treatment after drug discontinuation. Thus, maximally tolerated beta blockade is an effective therapy for unstable angina.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗
PubMed1988

Hemodynamic effects of contrast media during coronary angiography: a comparison of three nonionic agents to Hypaque-76.

Coronary angiography with standard ionic contrast media is associated with marked alterations in cardiac hemodynamics because of the depressant effects of the contrast media on cardiac contractility. Nonionic contrast media have been reported to produce less hemodynamic alteration than standard ionic contrast media. However, there is no information on how one nonionic media compares to another. Thus we compared the hemodynamic effects of three nonionic contrast media, Iopamidol (IOP), Iohexol (IOH), and Ioversol (IOV) to each other as well as to the standard ionic contrast media Hypaque-76 (H76). In 20 closed-chest anesthetized dogs, we recorded the maximal change in left ventricular systolic pressure (LVSP), mean aortic pressure, left ventricular diastolic pressure (LVDP), and left ventricular dp/dt during 10-cc left main coronary artery injections of H76, IOP, IOH, and IOV. The mean aortic pressure and LVSP decreased 36 +/- 17 mm Hg and 46 +/- 21 mm Hg with H76 but only 5 +/- 5 mm Hg and 6 +/- 5 mm Hg with IOP, 5 +/- 4 mm Hg and 6 +/- 6 mm Hg with IOH, and 5 +/- 4 mm Hg and 7 +/- 6 mm Hg with IOV (P less than 0.001). The LVDP increased 6 +/- 5.0 mm Hg with H76 but only 0.2 +/- 0.5 mm Hg with IOP, 0.2 +/- 0.3 mm Hg with IOH, and 0.5 +/- 1.0 mm Hg with IOV (P less than 0.001). The LV dp/dt decreased 545 +/- 261 mm Hg/sec with H76 but increased 886 +/- 477 mm Hg/sec with IOP, 910 +/- 96 mm Hg/sec with IOH, and 473 +/- 335 mm Hg/sec with IOV (P less than 0.001). Whereas each nonionic agent produced significantly less hemodynamic abnormalities than H76, there was no significant difference between any of the nonionic agents on any hemodynamic parameter. Thus, as compared to H76, these nonionic contrast media produced only trivial alterations in hemodynamics and LV dp/dt. These agents may be preferable in patients with LV dysfunction.

Angiography↗
PubMed1988

Differential hemodynamic effects of Hypaque-76 and Renografin-76 during coronary angiography: the role of calcium-binding additives.

Hypaque-76 (H76) and Renografin-76 (R76) are nearly identical ionic contrast media, except that R76 binds more calcium than H76 because of the presence of sodium citrate and EDTA in R76. To determine whether the calcium-binding additives in ionic contrast media contribute to the hemodynamic effects of contrast media during coronary angiography, left coronary angiography was performed in anesthetized dogs. In nine closed-chest dogs, 10 cc of H76 and R76 were injected in each dog in a blinded, randomized fashion. The effect of H76 and R76 on left ventricular systolic pressure (LVSP) and left ventricular diastolic pressure (LVDP), on mean aortic pressure (MAP), and on left ventricular (LV) dp/dt was recorded. Compared with H76, R76 produced a greater decrease in the LVSP (77 +/- 25 mmHg vs 48 +/- 17 mmHg P less than .05), MAP (72 +/- 24 mmHg vs 38 +/- 18 mmHg P less than .01), and LV dp/dt (747 +/- 87 mmHg/sec vs 460 +/- 81 mmHg/sec P less than .01). In nine additional open-chest dogs, left coronary angiography was performed 1 hour after occlusion of the proximal LAD coronary artery. Seven cc R76 produced a 35 +/- 15 mmHg decrease in LVSP, compared with 20 +/- 9 mmHg with H76 (P less than .01). The LV dp/dt decreased 720 +/- 387 mmHg/sec with R76, compared with 462 +/- 222 mmHg/sec with H76 (P less than 0.05). Thus, R76 produces significantly greater hemodynamic abnormalities than H76. Contrast media lacking calcium-binding agents may be preferable for coronary angiography.

Animals↗
PubMed1988

The duration of coronary occlusion influences adrenergic contributions to reperfusion ventricular arrhythmias.

To study the role of the adrenergic nervous system in the genesis of nonlethal reperfusion arrhythmias, the proximal left anterior descending coronary artery was occluded for either 1 or 3 hours in 48 open-chest dogs anesthetized with alpha-chloralose. Heart rate was controlled (90 to 110 beats/min) by bilateral vagotomy and continuous right vagal stimulation. Dogs were treated with either saline, timolol (0.1 mg/kg), or prazosin (0.5 mg/kg) 15 minutes prior to reperfusion. Reperfusion after 1 hour of occlusion in saline-treated dogs evoked sustained polymorphic ventricular tachycardia (204 +/- 9 beats/min) that reverted to sinus rhythm by 15 minutes of reperfusion. The maximum rate of ventricular tachycardia was significantly reduced by both prazosin and timolol. Both drugs also caused about a 50% reduction in the total number of ectopic beats in the first 10 minutes of reperfusion. With a 3-hour occlusion, reperfusion in saline-treated dogs caused sustained polymorphic ventricular tachycardia (135 +/- 15 beats/min) which persisted for several hours. Neither timolol nor prazosin significantly altered the ventricular ectopic rate in these dogs. Furthermore, bilateral stellate transection, left stellate stimulation, isoproterenol (0.5 mg/kg), or methoxamine (100 ug/kg) all failed to alter the ventricular ectopic rate in the saline-treated dogs. Ventricular ectopy induced by reperfusion after a 1- or 3-hour occlusion was overdriven in all dogs by rapid atrial pacing. The results suggest that the nature of reperfusion-induced ventricular ectopy is highly dependent upon the preceeding duration of coronary occlusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Comparison of the effects of acute and chronic beta-blockade on infarct size in the dog after circumflex occlusion.

In order to compare the effects of acute and chronic beta-blockade on infact size, the left circumflex coronary artery was occluded for 6 hours in 33 anesthetized dogs. The dogs (18 to 22 kg) were divided into three groups; group 1 (N = 10) served as controls, group 2 received intravenous nadolol (average dose 1.25 mg/kg) just prior to coronary occlusion, and group 3 received oral nadolol (80 mg) twice daily for 16 days prior to coronary occlusion. To ensure equivalent degrees of beta-blockade at the time of occlusion, group 2 and 3 dogs were given incremental doses of intravenous nadolol to abolish the chronotropic response to isoproterenol (2 mu/kg IV). Left ventricular pressure, its first derivative (dP/dt), and heart rate were monitored. The anatomic risk region was determined antemortem by Evan's blue staining while the infarct zone was delineated postmortem by tetrazolium staining. Compared to Group 1, heart rate was 22% lower in group 2 and 15% lower in group 3 dogs 6 hours after occlusion (p less than 0.05). There were no differences among groups in peak left ventricular systolic pressure or mean arterial pressure. Infarct size as a function of the area at risk was 68 +/- 3% in group 1, 52 +/- 7% in group 2, and 44 +/- 8% in group 3. A significant difference was found only between groups 3 and 1. The data suggest that chronic beta-blockade provides greater protection against ischemic-induced necrosis than does acute beta-blockade. The greater protective effect of chronic beta-blockade may be due to chronic adaptive changes in either blood flow or metabolism.

Adrenergic beta-Antagonists↗
PubMed1988

Effect of propranolol on ventricular repolarization and refractoriness: role of beta-blockade versus direct membrane effects.

The purpose of this study was to define the role of beta-adrenergic blockade and direct membrane effects in the ability of dl-propranolol to alter ventricular repolarization and refractoriness in the intact heart. The effective refractory period (ERP) and the local Q-T interval were measured at an epicardial site in the left ventricle in 14 open-chest dogs anesthetized with alpha-chloralose. Beta-adrenergic influences were eliminated in seven dogs (group 1) by stellate transection and nadolol (0.5 mg/kg IV), and enhanced in seven dogs (group 2) by stellate transection and stimulation of the left ansae subclavia. Each dog received an initial beta-blocking dose of propranolol (0.5 mg/kg) followed by a second, cumulative dose of 5.0 mg/kg. In group 1 dogs, there was no significant change in either the ERP or local Q-T interval in response to the first dose of propranolol. In group 2 dogs, left stellate stimulation significantly shortened the ERP (20 +/- 2 msec) and the local Q-T interval (17 +/- 4 msec). The first dose of propranolol prolonged these parameters to values not different from prestimulation control values. There was no change in the H-V interval, QRS complex duration, or diastolic threshold (DT) in either group after the initial propranolol dose. The second dose of propranolol significantly shortened the ERP (5 +/- 1 msec) and the local Q-T interval (11 +/- 2 msec) in both groups. This dose also significantly increased the DT, H-V interval, and QRS complex duration.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗
PubMed1988

Progression of coronary artery disease after percutaneous transluminal coronary angioplasty.

Thirty-nine patients underwent coronary arteriography 1 to 20 months (mean 7 months) after percutaneous transluminal coronary angioplasty (PTCA). At the time of the repeat study, 35 patients (90%) had recurrent angina or myocardial infarction, and 4 patients (10%) were asymptomatic. Restenosis, defined as greater than 50% loss of PTCA gained diameter, was found in 19 patients (49%). In addition, 20 patients had new lesions or marked progression of existing lesions (defined as greater than 20% or increasing greater than 20% obstruction in coronary diameter) in the previously normal or mildly diseased coronary segments. The new or progressive lesions occurred both in patients with restenosis at the PTCA site (nine of 19) and in patients without restenosis (11 of 20). New or progressive lesions tended to occur more commonly in the artery on which PTCA was performed (13 of 40) than in the artery that did not have PTCA (10 of 77) (p less than 0.02 by chi 2). In arteries that had PTCA, new or progressive lesions occurred more often in the segment proximal to the angioplasty site (seven of 13 or 54%) than in the peri-PTCA segment (two of 13 or 15%) and in the segments distal to it (four of 13 or 31%), but this observation did not reach statistical significance. No other clinical, angiographic, or PTCA procedure variables affected the occurrence of new or progressive lesions. In patients with recurrent angina or myocardial infarction after PTCA, both restenosis and new or progressive lesions are common. New lesions or marked progression of existing lesions tended to occur in the vessel subjected to PTCA.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Contrast media-induced ventricular fibrillation. A comparison of Hypaque-76, Hexabrix, and Omnipaque.

Contrast media occasionally produce ventricular fibrillation during coronary angiography. We compared the fibrillatory propensity of the conventional ionic contrast medium, Hypaque-76 (H76) to the low osmolar ionic dimer Hexabrix (HB) and to the nonionic agent Omnipaque (OM) in 20 open chest anesthetized dogs. Intracoronary injection of 6 mL of contrast medium produced spontaneous ventricular fibrillation in four of ten dogs with H76, compared with two of ten with HB, and zero of ten with OM (P = .07). The induction of two premature beats by programmed stimulation of the myocardium during injection of 4 mL of contrast medium produced ventricular fibrillation in ten of ten dogs with H76, compared with three of ten with HB, and zero of ten with OM (P less than .001). Both H76 and HB produced ventricular fibrillation in ten of ten dogs when three premature beats were induced, compared with two of ten dogs with OM (P less than .001). Four mL H76 produced a 109 +/- 18 msec increase in the QT interval, compared with an 82 +/- 17 msec increase with HB, and a 45 +/- 12 msec increase with OM. We conclude that both low osmolar HB and OM are less fibrillatory than the conventional ionic medium H76, and that the nonionic medium OM is less fibrillatory than the ionic dimer contrast medium HB.

Angiography↗
PubMed1988

Effects of contrast media on the conducting system of the heart during coronary angiography. A comparison of Renografin-76 to Hypaque-76.

Electrocardiographic changes induced by ionic contrast media can cause complications during coronary angiography. A conduction delay through various parts of the heart is one factor in the genesis of asystole or ventricular fibrillation. Hypaque-76 (H76) and Renografin-76 (R76) are nearly identical ionic contrast media except that R76 binds more calcium than H76 because of the presence of sodium citrate and EDTA in R76. To determine whether the calcium binding additives in ionic contrast media contribute to the cardiac conduction abnormalities, we examined conduction time through the atrioventricular (AV) nodal tissue (via bipolar His bundle electrograms) and through the distal part of the conduction system (recording the QRS complex from the ECG) during coronary angiography. We injected 10 mL of H76 and R76 in 19 closed chest dogs in a blinded, randomized fashion during coronary angiography. The effects of H76 and R76 on heart rate, AH interval, HV interval, V interval and PR interval, and QRS complex duration were recorded. In 14 nonatrial pacing dogs, compared with H76, R76 produced a greater increase in the AV interval (32.9 +/- 6 milliseconds vs 12.4 +/- 2 milliseconds, P less than .01) and the PR interval (29.6 +/- 6 milliseconds vs 11.9 +/- 4 milliseconds, P less than .02). Additionally, the heart rate decreased 13.9 +/- 3.5 beats/minute from control with R76 compared with a decrease of 4.2 +/- 2.6 beats/minute from control with H76 (P less than .05). There was no significant difference between the prolongation of the HV interval and V interval, or QRS complex duration generated by R76 and H76.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiography↗
PubMed1988

Comparative effects of antiarrhythmic drugs on the ventricular fibrillation threshold.

The purpose of this study was to compare the effects of several different antiarrhythmic drugs on the ventricular fibrillation threshold (VFT). Experiments were performed on open-chest dogs anesthetized with pentobarbital. The VFT was measured on the right ventricle by scanning the vulnerable period with a single 10-ms electrical stimulus. The following antiarrhythmic drugs were each given intravenously to eight different dogs: procainamide (25 mg/kg), lidocaine (2 mg/kg + 70 micrograms/kg/min), flecainide (3 mg/kg), timolol (0.1 mg/kg), clofilium (1 mg/kg), dl-sotalol (5 mg/kg), and bethanidine (4 mg/kg). The drugs resulted in the following increases in the VFT: procainamide, 33 +/- 13%; lidocaine, 21 +/- 5%; flecainide, 38 +/- 10%; timolol, 19 +/- 6%; clofilium, 14 +/- 6%; sotalol, 33 +/- 10%; and bethanidine, 69 +/- 15%. The changes in VFT were all significant (p less than 0.01) except for clofilium. Only procainamide and sotalol caused stimulus-induced runs of nonsustained polymorphic ventricular tachycardia that spontaneously reverted to sinus rhythm after 4 s or more. In individual experiments, the occurrence of nonsustained polymorphic tachycardia that resembled ventricular fibrillation could not be correlated with a change in the VFT. In addition, there appeared to be no relationship between a drug-induced increase of the VFT and alterations in the QRS duration, the QT interval, or the ventricular effective refractory period. Bethanidine had the greatest effect on the VFT, in spite of the fact that this drug shortened the ventricular effective refractory period.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Effect of esmolol on the ventricular fibrillation threshold.

The effect of esmolol on the ventricular fibrillation threshold (VFT) was determined in 11 open-chest dogs anesthetized with sodium pentobarbital. Since changes in VFT by antiarrhythmic drugs have been shown to depend on the method used to test vulnerability to fibrillation, two methods were studied. The vulnerable period was scanned with a train of pulses (100 Hz, 4 ms, 20 pulses) in nine experiments and a single pulse (10 ms) in eight experiments. Following control measurements, esmolol was administered as an intravenous bolus of 500 micrograms/kg followed by a continuous infusion of 300 micrograms/kg/min. After 15 min of infusion, the adequacy of beta-blockade was tested by the administration of 0.5 micrograms/kg of isoproterenol. Isoproterenol increased the heart rate by only 18 +/- 2 beats/min following esmolol administration which was significantly less than the control response (79 +/- 7 beats/min, p less than 0.01). Although the VFT measured with the single-pulse technique did not change in response to esmolol (14.1 +/- 1.1 mA vs. 14.3 +/- 1.2 mA), the VFT measured with the train-of-pulses technique significantly increased (3.7 +/- 0.5 mA to 14.5 +/- 2.8 mA, p less than 0.01). Twenty minutes after discontinuing esmolol, the VFT measurements were repeated and did not differ from control values with either technique. The increase in heart rate in response to isoproterenol also returned to control values (80 +/- 6 beats/min). The results suggest that the ability of esmolol to raise VFT as measured by the train-of-pulses technique is due to beta-adrenergic blockade.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗
PubMed1988

Effects of chronic beta-blockade on beta-receptors and adenylate cyclase activity in the canine heart.

To test the hypothesis that beta-receptors 'up-regulate' during chronic beta-blockade, myocardial beta-receptor density, affinity and functional sensitivity were examined in dogs before and after chronic beta-blockade. Membrane preparations from the left ventricle and right atrium were assayed for beta-receptors in 8 control dogs, and 8 dogs given oral nadolol (4 mg/kg) twice a day for 3 weeks. Beta-receptor density and affinity of membrane fractions were determined using 3H-dihydroalprenolol (0.5-20 nM), and Scatchard analysis. Beta-receptor densities after chronic beta-blockade were 419 +/- 28 (mean +/- SEM) and 436 +/- 47 fmol/mg protein in membranes from the left ventricle and right atrium respectively. These values were not significantly different from the left ventricle (412 +/- 25) or the right atrium (413 +/- 25) in control dogs. Beta-receptor affinities were 5.6 +/- 0.5 nM (left ventricle) and 8.5 +/- 1.1 nM (right atrium) after chronic beta-blockade, and not significantly different from control (6.9 +/- 0.7 nM, ventricle; 11.3 +/- 0.9 nM, atrium). Beta-receptor sensitivity was determined in membrane fractions from the left ventricle by analysis of the dose-response relationship between isoproterenol and the formation of c-AMP (pmol/min/mg protein). The concentration of isoproterenol that resulted in 50% of the maximal response was not significantly altered by chronic beta-blockade. Maximally stimulated adenylate cyclase with Gpp(NH)p or NaF was also unchanged by beta-blockade. These results suggest that in the canine heart, chronic beta-blockade does not lead to 'up-regulation' of beta-receptors nor catecholamine supersensitivity.

Adenylyl Cyclases↗
PubMed1988

The effects of rapid volume expansion on the right and left cardiac filling pressures after coronary artery bypass surgery.

Rapid volume expansion is a diagnostic procedure which can reveal typical hemodynamics of pericardial constriction in patients with pericardial disease who have normal hemodynamics in their baseline state. We studied 20 patients with previous coronary artery bypass surgery in order to determine whether this operation results in some degree of pericardial constriction which could be demonstrated by rapid volume expansion. After infusing 1 L of physiologic saline solution over six minutes, the right atrial pressure increased by 5 +/- 2 mm Hg, the right ventricular diastolic pressure by 4 +/- 3 mm Hg, the pulmonary capillary wedge pressure by 7 +/- 3 mm Hg, and the left ventricular diastolic pressure by 7 +/- 4 mm Hg (mean +/- SD). Equalization of the left and right cardiac pressures was not observed, and the normal respiratory variation of the pressures was not altered by rapid volume expansion. Thus, the pericardial manipulation associated with the performance of coronary artery bypass surgery does not commonly result in the development of subclinical pericardial constriction.

Adult↗
PubMed1988

Coronary angiography during acute myocardial infarction in dogs: comparison of the hemodynamic effects of ionic and nonionic contrast media.

We compared the hemodynamic effects during coronary angiography of three nonionic contrast media, iopamidol, iohexol, and ioversol, with each other as well as with the standard ionic contrast medium containing 66% diatrizoate meglumine and 10% diatrizoate sodium (Hypaque-76) in the presence of a left anterior descending coronary artery occlusion in dogs. In 13 opened-chest anesthetized dogs, we recorded the maximal change in left ventricular systolic pressure (LVSP), mean aortic pressure (MAP), left ventricular diastolic pressure (LVDP) and rate of rise in left ventricular pressure (LV dp/dt) during left main coronary artery injections of 10 ml each of Hypaque-76, iopamidol, iohexol, and loversal 1 hour after left anterior descending coronary artery occlusion. The changes in LVSP and MAP were, respectively, -29 +/- 12 mm Hg and -21 +/- 11 mm Hg with Hypaque-76, 3 +/- 6.6 mm Hg and -0.2 +/- 3.6 mm Hg with iopamidol, 4.8 +/- 8.6 mm Hg and 0.5 +/- 4 mm Hg with iohexol, and -0.8 +/- 6 mm Hg and -1.5 +/- 33 mm Hg with ioversal (p less than 0.001). The change in LVDP was 5.4 +/- 4.4 mm Hg with Hypaque-76 but -1.5 +/- 3.1 mm Hg with iopamidol, -1.7 +/- 2.4 mm Hg with iohexol, and -0.5 +/- 2.5 mm Hg with ioversol (p less than 0.001). The LV dp/dt decreased 682 +/- 318 mm Hg/sec with Hypaque-76, but increased 412 +/- 297 mm Hg/sec with iopamidol, 350 +/- 214 mm Hg/sec with iohexol, and 293 +/- 191 mm Hg/sec with ioversol (p less than 0.001). Thus, each nonionic agent produced significantly fewer hemodynamic abnormalities than Hypaque-76. There was no significant difference between any of the nonionic agents on any hemodynamic parameter. These agents may be preferable in patients with acute myocardial infarction or significantly impaired myocardial function.

Acute Disease↗