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 47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Effects of ionic (Hypaque-76) and nonionic (Isovue-370 and Omnipaque-350) contrast media on oxyhemoglobin dissociation of normal human red blood cells were evaluated. In series 1, 4-mL venous blood samples were obtained from 15 normal human volunteers. One blood sample served as control, and 1 mL of either of the three contrast media was added in vitro to the other 4-mL blood samples. P50 values were estimated from the linear portion of the oxyhemoglobin dissociation curve obtained by tonometry. Determinations of P50 were performed at either pH 7.4 or 7.2. At pH 7.4, P50 in the absence of contrast media was 26.3 +/- 0.4 mm Hg (mean +/- SEM). The contrast media caused comparable decreases in P50 from this value (Hypaque-76, 20.0 +/- 0.5 mm Hg; Omnipaque-350, 21.6 +/- 0.4 mm Hg; Isovue-370, 20.7 +/- 0.4 mm Hg). Reducing pH to 7.2 in the absence of contrast media increased P50 to 33.3 +/- 1.0 mm Hg, evidence of the Bohr effect. The presence of contrast media either completely abolished (Hypaque-76 and Omnipaque-350) or markedly attenuated (Isovue-370) this effect. In series 2 (five patients), blood samples were withdrawn from the external iliac artery during injection of Isovue-370 (60-78 mL) into the proximal abdominal aorta to evaluate peripheral vascular disease. Measurement of P50 of these samples yielded findings consistent with those of series 1. The present findings demonstrate that both ionic and nonionic contrast media increase the affinity of hemoglobin for oxygen and, therefore, that they may inhibit oxygen delivery to body tissues.
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PMID:Contrast media adversely affect oxyhemoglobin dissociation. 236 33

To assess the therapeutic effect of percutaneous transluminal coronary angioplasty (PTCA) on coronary flow reserve, coronary flow velocity (CFV) was measured with a Doppler catheter before and immediately after PTCA in 11 patients, who underwent elective PTCA for critical stenosis in proximal or mid portion of the left anterior descending artery (LAD). A Doppler catheter was positioned at the proximal portion of the LAD and the CFV was measured at rest and after intracoronary injection of 6 ml of contrast material (Iopamidol), 6 ml of saline or 3 mg of Isosorbide Dinitrate (ISDN). Peak to resting velocity ratio (PRVR) was calculated as an estimate of coronary flow reserve. Percent diameter stenosis (%S) was measured from cineangiogram. A translesional pressure gradient was obtained with an angioplasty catheter. These parameters measured in PTCA candidates were compared with those in 11 patients whose LAD had no critical stenosis. After PTCA, %S was decreased (94.2 +/- 1.4 vs 34.1 +/- 5.1%; mean +/- SEM). Pressure gradient was also decreased (59.5 +/- 4.9 vs. 25.1 +/- 3.3 mmHg). There was no difference between mean CFV at rest in patients before PTCA and that in patients without stenosis (4.52 +/- 0.63 vs. 5.46 +/- 0.61 cm/sec). By successful PTCA, CFV at rest was increased (7.39 +/- 1.32, p less than 0.05 vs. before PTCA). PRVRs in patients before PTCA were smaller than those in patients without stenosis (1.5 +/- 0.1, 1.4 +/- 0.1, 1.6 +/- 0.2 vs. 2.8 +/- 0.1, 2.5 +/- 0.2, 2.8 +/- 0.2, p less than 0.01; by contrast material, saline, ISDN, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Measurement of coronary flow velocity with Doppler catheter: evaluation of coronary flow reserve in successful angioplasty]. 252

Catheter-induced ventricular ectopy can limit assessment of contractility or anatomy. We compared the incidence of ventricular ectopy in infants and children undergoing left ventriculography using a 4F Halo catheter or a 4F pigtail catheter. For each group, 17 patients had 19 ventriculograms. Iopamidol 76% was used for each study. There was no statistical difference between the Halo and pigtail groups (mean+/-SEM) for age (16.2+/-3.8 vs. 12.9+/-1.8 mo), weight(8.1+/-1.0 vs. 8.0+/-0.7 kg), gender, left ventricular end diastolic pressure (9.6+/-1.1 vs. 9.8+/-1.3 mm Hg), catheter location in the ventricle, or volume of contrast (1.31+/-0.06 vs. 1.35+/-0.06 cc/kg). The Halo group had a more rapid injection rate (1.42+/-0.15 vs. 0.99+/-0.10 cc/kg/sec, P< 0.02). The Halo group had a lower overall incidence of ventricular ectopy (3 vs. 13 studies, P < 0.001), ventricular ectopy >1 beat (1 vs. 10 studies, P < 0.002), and ventricular couplets or tachycardia (1 vs. 9 studies, P < 0.008). The 4F Halo catheter is associated with less ventricular ectopy than a 4F pigtail catheter and should be considered for use during pediatric catheterization.
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PMID:Reduced incidence of ventricular ectopy with a 4F Halo catheter during pediatric cardiac catheterization. 947 92