An experimental study on the preventive effects of N-acetyl cysteine and ozone treatment against contrast-induced nephropathy

Abstract Purpose: To compare the preventive effects of N-acetyl cysteine (NAC), ozone preconditioning and ozone treatment against contrast-induced nephropathy (CIN) in an experimental rat model. Methods: Thirty adult male Wistar rats were randomly distributed into five groups (n=6 for each group). Group I served as control and Group II had only contrast agent, while Group III received NAC and Group IV received intraperitoneal ozone 6 hours before and 6 hours after introduction of contrast agent. Ozone treatment was applied for 5 days after the contrast agent was introduced in Group V. After induction of CIN, groups were compared in terms of serum levels of urea, creatinine, neutrophil gelatinase associated lipocalin, protein carbonyl, total antioxidant capacity (TAC) as well as degree of renal injury at histopathologic level. Results: Groups II-V displayed more obvious histopathological alterations such as hemorrhage and renal tubular injury compared with Group I. TAC (p=0.043) and creatinine (p=0.046) levels increased significantly in Group II after the intervention. In Group III, protein carbonyl level diminished remarkably (p=0.046), while creatinine level was increased (p=0.046) following the intervention. TAC level was higher in Group IV (p=0.028) and Group V (p=0.026) following the procedure. Conclusion: The N-acetyl cysteine and ozone treatment may alleviate the biochemical and histopathological deleterious effects of contrast-induced nephropathy via enhancement of total antioxidant capacity and decreasing oxidative stress.

Nondestructive Assessment of Glycosaminoglycans in Engineered Cartilages Using Hexabrix-Enhanced Micro-Computed Tomography

It is very useful to evaluate the content and 3D distribution of extracellular matrix non-destructively in tissue engineering. This study evaluated the feasibility of using micro-computed tomography (µCT) with Hexabrix to measure quantitatively sulfated glycosaminoglycans (GAGs) of engineered cartilage. Rabbit chondrocytes at passage 2 were used to produce artificial cartilages in polyglycolic acid scaffolds in vitro. Engineered cartilages were incubated with Hexabrix 320 for 20 min and analyzed via µCT scanning. The number of voxels in the 2D and 3D scanning images were counted to estimate the amount of sulfated GAGs. The optimal threshold value for quantification was determined by regression analysis. The 2D µCT images of an engineered cartilage showed positive correlation with the histological image of Safranin-O staining. Quantitative data obtained with the 3D µCT images of 14 engineered cartilages showed strong correlation with sulfated GAGs contents obtained by biochemical analysis (R² = 0.883, p < 0.001). Repeated exposure of engineered cartilages to Hexabrix 320 and µCT scanning did not significantly affect cell viability, total DNA content, or the total content of sulfated GAGs. We conclude that µCT imaging using Hexabrix 320 provides high spatial resolution and sensitivity to assess the content and 3D distribution of sulfated GAGs in engineered cartilages. It is expected to be a valuable tool to evaluate the quality of engineered cartilage for commercial development in the future.

The Effect of Radiographic Contrast Media on Reperfusion Injury in the Isolated Rat Heart

BACKGROUND AND OBJECTIVES: We investigated the effects of commonly used contrast media (CM) on myocardial ischemia-reperfusion injury in isolated rat hearts. SUBJECTS AND METHODS: Isolated rat hearts were subjected to 30 minutes of regional ischemia and 2 hours of reperfusion. The following CM (1 mL/1 L Krebs-Henseleit buffer) were randomly perfused for 15 minutes beginning 5 minutes before reperfusion and ending 10 minutes after reperfusion: iohexol (n=8), iopromide (n=8), ioversol (n=8), iomeprol (n=8), iopamidol (n=7), ioxaglate (n=8), and iodixanol (n=7). The effects of a direct bolus injection of undiluted iohexol, iopromide, or ioxaglate (each n=6) via the aortic root immediately prior to reperfusion were also evaluated. The area of necrosis, expressed as the percentage of the area at risk (AN/AR), and cardiodynamic variables were measured. RESULTS: The AN/AR of the control and experimental groups in the order described in methods was 33.7+/-6.4%, 30.3+/-7.4%, 34.7+/-12.6%, 29.2+/-10.2%, 20.9+/-7.6%, 22.6+/-8.7%, 18.8+/-7.9%, and 19.9+/-11.4%, respectively. Groups that received iomeprol and ioxaglate exhibited significantly decreased AN/AR values compared to those of control hearts (p=0.042 and p=0.013). No significant differences in the AN/AR were observed between control hearts and the groups injected with a single bolus of CM. No significant hemodynamic changes were noted after reperfusion among the groups. CONCLUSION: The overall effects of the CM on coronary reperfusion were not deleterious, and better effects were noted in two CM groups. However, it is unclear whether this result was attributed to a specific physiochemical property of the CM.

Assessment of Myocardial perfusion in Patients with Acute Myocardial infarction

BACKGROUND: Unlike 99mTc-Sestamibi, microbubbles used during myocardial contrast echocardiography (MCE) exist only in the vascular space. Therefore, there may be a difference in the pattern of myocardial perfusion between MCE and 99mTc-Sestamibi Single-Photon Emission Computed Tomography (SPECT) in acute myocardial infarction (AMI). OBJECTIVES: The purpose of this study was to assess myocardial perfusion using MCE with intravenous infusion of perfluorocarbon-exposed sonicated dextrose albumin microbubbles (IV MCE), and to compare it with SPECT and MCE with intracoronary injection of sonicated Hexabrix (IC MCE). METHODS: Seventeen patients with AMI (male 13, age 59.5+/-8.8 years, anterior MI 10) underwent IV MCE at 8.1+/-3.7 days after onset. SPECT and IC MCE were also performed at 1.2+/-1.0 days and 2.0+/-1.5 days from IV MCE respectively. Any revascularization procedures were not performed between three studies. Perfusion defect by three methods was scored semiquantitatively as 1 : normal perfusion, 0.5 : moderate defect, and 0 : severe defect at 16 segments of the left ventricle. RESULTS: 1) Perfusion defect in infarction territory was detected in 15 patients with SPECT, 12 patients with IV MCE and 11 patients with IC MCE. 2) Concordance of perfusion score at each segment was 93% between IV MCE and IC MCE, 65% between IV MCE and SPECT, and 64% between IC MCE and SPECT. 3) With IV MCE, perfusion defect was observed in all 32 segments which were considered as having defect (score 0 and 0.5) by IC MCE. However, defect by IV MCE was found only in 31 out of 108 segments considered as having defect by SPECT. CONCLUSION: In the assessment of myocardial perfusion in pts with AMI, IV MCE and IC MCE showed similar results. However, there was some discrepancy in the extent of perfusion defect between MCE studies and SPECT.

The Evaluation of Diagnostic Validity of ECG for the Subendocardial Infarction by Myocardial Contrast Echocardiography

BACKGROUND AND OBJECTIVES: The pathological findings of Non-Q wave myocardial infarction(NQMI) on ECG did not always correspond to subendocardial infarction(SEMI). The purpose of this study was to evaluate the diagnostic validity of ECG for SEMI by myocardial contrast echocardiography (MCE) in the patients with acute myocardial infarction(AMI). MATERIALS AND METHODS: The study population was 84 patients who underwent MCE under the diagnosis of AMI. MCE was performed by intracoronary injection of sonicated Hexabrix into the infarct related artery and SEMI was diagnosed by inspecting endocardial defect with epicardial enhancement on MCE. RESULTS: (1) Among 19 NQMI cases, 7 cases showed SEMI with MCE score 0.5, 11 cases with score 1, and 1 case with score 0. Among 65 Q-wave MI(QMI) cases, only 5 cases showed SEMI. (2) 7 cases who had NQMI with SEMI showed LV wall motion recovery at follow-up echocardiography except 1 case. Whereas, of 5 QMI cases who had SEMI, only 1 case improve LV wall motion. CONCLUSION: NQMI on ECG does not always imply SEMI on MCE, but the absence of pathologic Q wave in the patients with SEMI is thought to be a predictive factor of the recovery of LV wall motion.

The Evaluation of Diagnostic Validity of ECG for the Subendocardial Infarction by Myocardial Contrast Echocardiography

BACKGROUND AND OBJECTIVES: The pathological findings of Non-Q wave myocardial infarction(NQMI) on ECG did not always correspond to subendocardial infarction(SEMI). The purpose of this study was to evaluate the diagnostic validity of ECG for SEMI by myocardial contrast echocardiography (MCE) in the patients with acute myocardial infarction(AMI). MATERIALS AND METHODS: The study population was 84 patients who underwent MCE under the diagnosis of AMI. MCE was performed by intracoronary injection of sonicated Hexabrix into the infarct related artery and SEMI was diagnosed by inspecting endocardial defect with epicardial enhancement on MCE. RESULTS: (1) Among 19 NQMI cases, 7 cases showed SEMI with MCE score 0.5, 11 cases with score 1, and 1 case with score 0. Among 65 Q-wave MI(QMI) cases, only 5 cases showed SEMI. (2) 7 cases who had NQMI with SEMI showed LV wall motion recovery at follow-up echocardiography except 1 case. Whereas, of 5 QMI cases who had SEMI, only 1 case improve LV wall motion. CONCLUSION: NQMI on ECG does not always imply SEMI on MCE, but the absence of pathologic Q wave in the patients with SEMI is thought to be a predictive factor of the recovery of LV wall motion.

Fractional transmural perfusion assessed by myocardial contrast echocardiography according to grades of collateral flow on coronary angiography / 대한내과학회지

BACKGROUND: A collateral flow can be assessed and graded by coronary angiography, however, the technique does not provide any information about perfusion. Myocardial contrast echocardiography (MCE) can assess collateral perfusion and has superior spatial resolution in defining its distribution. OBJECTIVE: To investigate the difference of transmural perfusion according to the angiographical collateral grade in normal myocardium, we performed MCE of collateral artery in 16 patients (m : f = 11 : 5, age: 57+/-13yrs.) with angina and compared the results with the angiographical grades. METHODS: In six patients with preexisting collaterals on baseline angiography, we performed MCE after intracoronary injection of sonicated Hexabrix. For 10 patients without preexisting collaterals on baseline angiography, we performed angiography, MCE for recruited collateral arteries during balloon inflation of stenotic coronary arteries (2 times for 120sec.). For 12 patients who underwent PTCA, we performed pressure wire simultaneously with angiography and MCE for recruited collateral arteries during balloon inflation. Fractional collateral flow(FCF) was defined by the ratio of coronary wedge pressure to proximal pressure(Pw/Pa). Angiographical collaterals were graded according to 'Rentrop' criteria(grade 0-3). Transmural thickness (TMT) and enhanced myocardial thickness (EMT) of an enhanced segment on MCE were measured at diastolic phase. The depth of collateral perfusion was estimated by collateral perfusion index (CPI) that was the ratio of EMT to TMT. RESULTS: There were significant differences of CPI with respect to angiographical grades according to one way ANOVA test (p< 0.05). One of five patients who had no recruited collaterals showed partial enhancement confined to the epicardium with CPI of 0.24. There was significant correlation between the angiographical grade and the CPI with Spearman's Rho value of 0.93(p< 0.0001). The angiographical grades were significantly correlated with FCF with the Spearman's Rho value of 0.87(p=0.0002). There was also significant correlation between FCF and CPI with Pearson's r=0.81 (p=0.0016). CONCLUSION: The higher the angiographical collateral grade is, the higher the collateral pressure and the deeper the fractional transmural perfusion from epicardium into endocardium gets.

Radiologic and Histopathologic Evaluation of Various Contrast Media for Bronchography

PURPOSE: To determine which contrast media are both efficient and safe for the imaging of airways. MATERIALS AND METHODS: We evaluated five contrast media (barium, gastrografin, iotrolan, ioxaglate, iopentol) in terms of image quality and their effects on the lungs of 25 white rabbits. For bronchography 0.5ml of contrast media was used. In each contrast group, HRCT scans were obtained immediately (n=5), 12 hours (n=4), 1 day (n=3), 2 days (n=2), and 1 week (n=1) after bronchography. Histopathologic specimens were obtained immediately, 12 hours, 1 day, 2 days, and 1 week later. Bronchograms were evaluated for image quality by three radiologists working independently, and were scored as 1(poor), 2(moderate), or 3(good) in terms of contrast quality and bronchial coating. HRCT was evaluated by two radiologists who reached a concensus; they determined the presence of contrast media, and then the pattern and extent of pulmonary opacity, and any related changes. Histopatholgic specimens were evaluated by two pathologists who sought consensus as to the extent of inflammation, pulmonary edema, and hemorrhage, and any changes in these aspects. RESULTS: Bronchography indicated that the sum of scores for contrast quality was 45 for barium, 33 for gastrografin, 28 for iotrolan, 30 for ioxaglate, and 28 for iopentol, while for each of these media, the sum of scores for bronchial coating was 39, 19, 25, 23, and 21, respectively. Barium showed the best image quality. In all rabbits, HRCT demonstrated the variable extent of groundglass attenuation and/or consolidation. Lesions were most extensive at 1-2 days and then regressed at 1 week; these HRCT findings correlated well with histologic findings. In histologic studies of all five contrast media groups, variable severe inflammatory reactions were observed, with or without necrosis, congestion, edema, and hemorrhage. It was noted that ioxaglate appeared to cause least tissue reaction. CONCLUSIONS: The imaging results of this experimental study indicate that for bronchography, barium is the best available contrast media, On the basis of the histologic and HRCT results, however, ioxaglate is the best.

Hemograma, sódio, potássio, cálcio, osmolalidade e viscosidade durante angiocardiografia pediátrica com ioxaglato / Blood cell count, sodium, potassium, calcium, osmolality and viscosity, during pediatric angiocardiography with ioxaglate

OBJETIVO - Os meios de contraste (MC) introduzem alteraçöes em alguns parâmetros sangüíneos, adquirindo, assim, mais importância na angiocardiografia pediátrica. MÉTODOS - Estudamos a presença e a severidade das mudanças no hematócrito, hemoglobina, leucócitos, sódio, potássio, cálcio, osmolalidade e viscosidade, em 35 crianças submetidas a angiocardiografia com ioxaglato, identificando, também, as variáveis independentes responsáveis por essas alteraçöes. As amostras sangüíneas foram colhidas no início do procedimento (S1), no fim (S2) e 2h após (S3). RESULTADOS - (...fórmula...). CONCLUSÄO - Variaçöes significativas nas variáveis dependentes medidas foram observadas durante e após o procedimento. O uso do ioxaglato foi parcialmente relacionado a mudanças no hematócrito/hemoglobina, cálcio total e viscosidade mas näo as das variáveis restantes.

Assessment of myocardial perfusion status through the angiographically visible collaterals in the ischemic heart disease

BACKGROUND: It is well known that collateral circulation has important roles in ischemic heart diseases. The method most commonly used at present to evaluate collateral flow is coronary angiography. However, there are debates about the functional significance of angiographically visible collaterals because angiography visualizes only vessels that are larger than 100um in diameter. Recent studies suggest that myocardial contrast echocardiography (MCE) is a useful method in assessing collateral flow because it uses small microvascular tracers (4-12um) as a contrast agent. By using MCE, this study evaluates the role of angiographically visible collaterals in patients with acute myocardial infarction (AMI) and chronic ischemic heart disease. METHOD: Forty-one patients who underwent coronary angiography and MCE were included in this study (22 patients with acute myocardial infarction and 19 patients with chronic ischemic heart disease). Antegrade coronary flow was less than TIMI 3 flow in all patients. Myocardial perfusion through collaterals with MCE was evaluated by injecting sonicated Hexabrix into nonobstructing coronary arteries. Angiographically visualized collateral vessels were analysed as four grades and compared with the degree of myocardial opacification by MCE through collateral vessels. RESULT: Angiographic collaterals were frequently observed in patients with AMI and chronic ischemic heart disease with0.05). CONCLUSION: The study suggests that the role of angiographically visible collaterals is different in chronic ischemic heart disease and acute myocardial infarction. The grade of angiographically visible collaterals does not imply the extent of perfusion to myocardum at risk through collateral vessels.

Relation between Perfusion of Infarcted Myocardium and Exercise-induced ST Shift in Acute Myocardial Infarction

BACKGROUND: It has been demonstrated that within 2 weeks following acute myocardial infarction (AMI), exercise-induced ST-segment depression (STD) indicates subendocardial ischemia in the viable myocardium within infarcted or remote area from the infarction. Exercise-induced ST-segment elevation (STE) in leads with abnormal Q wave is associated with left ventricular dysfunction or aneurysm rather than transmural ischemia. We studied whether each pattern of ST-segment shift on exercise ECG during recovery phase following AMI is correlated with the perfusion status of infarcted myocardium evaluated by myocardial contrast echocardiog-raphy (MCE), regardless of findings of coronary angiography (CAG). METHOD: Study population was consisted of 25 patients with AMI (anteior wall: 11 patients, inferior wall: 14 patients, mean age=57.3+/-8.9years). Patients underwent exercise ECG and coronary angiography at 10 days post-AMI. After CAG, sonicated Hexabrix was injected into both coronory arteries alternatively and 2-D echocardiography was taken in parasternal short axis, apical 4, and 2 chamber views. To analyze the echocardiographic image semiquantitively, left ventricle was divided into 20 segments and perfusion status was graded as good, partial, and no opacification. RESULT: All patients with exercise-induced STE (n=8) in Q-leads had patent infarcted-related artery and poor collaterals on CAG, which was associated with poor or no opacification of infarcted myocardium on MCE. Patients with exercise-induced STD (n=9) frequently had closed infarct-related artery (67%), but good opacification of infarcted myocardium was shown by retrograde perfusion via collaterals, which was commonly seen in patients with multivessel disease. CONCLUSION: In early recovery phase of acute myocardial infarction, exercise-induced ST elevation in Q leads was associated with poor perfusional status in infarcted myocardium, even with patent infarct-related artery on CAG, while exercise-induced ST depression was frequently seen in the good perfusional status despite of closed infarted-related artery, which was commonly observed in patients with multivessel disease.

Relation between Perfusion of Infarcted Myocardium and Exercise-induced ST Shift in Acute Myocardial Infarction

BACKGROUND: It has been demonstrated that within 2 weeks following acute myocardial infarction (AMI), exercise-induced ST-segment depression (STD) indicates subendocardial ischemia in the viable myocardium within infarcted or remote area from the infarction. Exercise-induced ST-segment elevation (STE) in leads with abnormal Q wave is associated with left ventricular dysfunction or aneurysm rather than transmural ischemia. We studied whether each pattern of ST-segment shift on exercise ECG during recovery phase following AMI is correlated with the perfusion status of infarcted myocardium evaluated by myocardial contrast echocardiog-raphy (MCE), regardless of findings of coronary angiography (CAG). METHOD: Study population was consisted of 25 patients with AMI (anteior wall: 11 patients, inferior wall: 14 patients, mean age=57.3+/-8.9years). Patients underwent exercise ECG and coronary angiography at 10 days post-AMI. After CAG, sonicated Hexabrix was injected into both coronory arteries alternatively and 2-D echocardiography was taken in parasternal short axis, apical 4, and 2 chamber views. To analyze the echocardiographic image semiquantitively, left ventricle was divided into 20 segments and perfusion status was graded as good, partial, and no opacification. RESULT: All patients with exercise-induced STE (n=8) in Q-leads had patent infarcted-related artery and poor collaterals on CAG, which was associated with poor or no opacification of infarcted myocardium on MCE. Patients with exercise-induced STD (n=9) frequently had closed infarct-related artery (67%), but good opacification of infarcted myocardium was shown by retrograde perfusion via collaterals, which was commonly seen in patients with multivessel disease. CONCLUSION: In early recovery phase of acute myocardial infarction, exercise-induced ST elevation in Q leads was associated with poor perfusional status in infarcted myocardium, even with patent infarct-related artery on CAG, while exercise-induced ST depression was frequently seen in the good perfusional status despite of closed infarted-related artery, which was commonly observed in patients with multivessel disease.

The Comparative Hemodynamic Effects between Low Osmolar Ionic(Ioxaglate) and Non-ionic(Iopromide) Contrast Media during Left Ventriculography

BACKGROUND: Various hemodynamic changes occur during left ventriculography, such as myocardial depression, hypotension, peripheral circulatory changes, ECG changes(such as arrhythmias and conduction abnormalities) and anaphylactic reaction etc. These effects are somewhat caused by osmolality, ionic concentration of Na+, viscosity and molecular weight of contrast dye and underlying various heart disease itself during left ventriculography. We compared the hemodynamic differences between ionic(ioxaglate) and non-ionic(iopromide) low osmolar contrast agents during routine ventriculography. METHODS: In a prospective, randomized, double blind study of 124 patients underwent left ventriculography, we examined the various hemodynamic effects of the two contrast agents on left ventricle. All subjects were divided into 2 groups : ioxaglate and iopromide groups. Also, each agent was used in randomized double blind fashion in both groups ; normal control subjects(14 in ioxaglate group : 12 in iopromide group) and subjects whose ejection fraction less than 50%(12 in ioxaglate group : 16 in iopromide group). Left ventricular systolic pressure(LVSP), left ventricular end-diastolic pressure(LVEDP), maximum dP/dt, (dP/dt)/P ratio, peak - dP/dt and Tau were obtained immediately before and left ventriculography. RESULTS: 1) In total(normal+angina+MI) subjects of both groups, LVEDP(p<0.001) and maximum dP/dt(p<0.001) were increased and T(au) was reduced significantly(p<0.05). But LVSP(p<0.001) and peak - dP/dt(p<0.005) were increased significantly only in ioxaglate group. 2)In normal(control) subjects, there were no significant differences in both groups, except LVEDP that was increased by equal magnitude(p<0.001). 3) In subjects with ejection fraction less than 50%, there were no significant hemodynamic differences in both contrast agent groups bur LVEDP increased significantly in both groups(p<0.001). CONCLUSIONS: This present study showed that both ionic(ioxaglate) and non-ionic(iopromide) low osmolar contrast agents were very safe without any significant side effects except two agents caused an increase in LVEDP and did not show major differences between ioxaglate and iopromide contrast agents from a hemodynamic point of view. Two contrast agents tend to improve contractilities and diastolic properties of left ventricle since both caused an increase in maximum dP/dt and a reduce in Tau, in total subjects. This effect may be caused by cardiac compensation, probably because of osmolality, volume loading by contrast agents and secondary activation of sympathetic system immediately after injection of contrast agents. Thus, it is concluded that two ioxaglate and iopromide contrast agents amy be used safely in left ventriculography in patients with and without left ventricular dysfunction, with paying attention to an increase in LVEDP.

Effect of Percutaneous Transluminal Coronary Angioplasty on Myocardial Perfusion : Measurement with Myocardial Contrast Echocardiography

BACKGROUND: Myocardial contrast echocardiography(MCE) has been known to be a safe and useful method to assess the adequacy of myocardial perfusion. This study was performed to assess the change of myocardial perfusion following successful percutaneous transluminal coronary angioplasty using MCE in the patients with significant coronary arterial obstructive diseases. METHODS: The study comprised of eight patients(mean age 55 years, male 7, female 1). Four patients were unstable angina and four patients post non-Q wave myocardial infarction angina. Six patients had one vessel disease and two paients two vessel disease. All patients underwent successful PTCA at the proximal(2 patients) and the mid(6 patients) left anterior descending coronary artery. Pre- and post-PTCA myocardial perfusion was assessed by comparing peak contrast intensity and slope of time-intensity curve after injection of hand-agitated Hexabrix(6cc) respectively. The variables were measured off-line at thirty two end-diastolic frames of the left ventricle in each patient. RESULTS: 1) Diameter stenosis of target lesion changed from 91±9 to 24±14% after successful coronary angioplasty(p < 0.005). 2) Peak contrast intensity was increased from 47.4±30.7 to 64.9±36.4 gray scale U/pixel in anteroseptal segment and from 46.6±14.3 to 67.9±35.8 gray scale U/pixel in anterior segment(p < 0.05). 3) The slope of time-intensity curve after PTCA became more steeper compared to that of pre-PTCA(anteroseptal : −0.32±0.48 vs −0.76±0.66 p=0.071, anterior : −0.33±0.39 vs −0.81±0.80 p=0.086). 4) During the study, there was no significant clinical or hemodynamic complications except three patients who developed transisient sinus bradycardia after intracoronary injection of handagitated Hexabrix. CONCLUSION: Myocardial contrast echocardiography appeared to be safe and useful in the evaluation of myocardial perfusion following coronary angioplasty assessed by the changes of peak contrast intensity and slope of contrast time-intensity curve.

Asessment of Myocardial Reperfusion by Myocardial Contrast Echocardiography and Its Relation to Viable Myocardium

BACKGROUND: As lack of myocardial perfusion was demonstrated on myocardial contrast echocardiography(MCE) despite angiographic documentation of reflow, patency of infarct related artery (IRA) after acute myocardial infarction(AMI) does not guarantee myocardial tissue perfusion. Myocardial enhancement on MCE is associated with myocardial perfusion and microvascular integrity. We are to assess myocardial perfusion immediately after thrombolysis and to correlate myocardial enhancement with functional recovery of postischemic dysfunctional myocardium. METHODS: MCE was performed by intracoronary injection of hand-agitated Ioxaglate in 17 consecutive AMI patients immediately after thrombolysis. Myocardial enhancement of 37 infarct segment was quantified as corrected peak videointensity(PI) by videodensitometry and the PI ratio of infarct to normal segments was used to assess myocardial reperfusion. Viable myocardium was defined as the presence of functional recovery on follow-up echocardiography. RESULTS: 1) MCE was performed in 37 segments of 17 AMI patient and functional recovery was noted in 28 segments of 12 patients on follow-up echocardiography. 2) Six infarct segments with no reflow on MCE showed severe fixed perfusion defect in thallium scan and no functional recovery in follow-up echocardiography. 3) The peak cardiac enzyme level was significantly higher in patients without functional recovery(p<0.005), but mean PI ratio(p<0.005) and patency of IRA(p<0.05) were significantly higher in patient with functional recovery. Age, sex, time to thrombolysis and stenosis of IRA were not associated with functional recovery. 4) Apical segment(p<0.01), TIMI grade 2 patency(p<0.01) and LAD territory(p<0.05) were significantly associated with nonviable myocardium, and PI ratio(p<0.001) was significantly correlated to viable myocardium. The PI ratio was the most significant predictor of myocardial functional recovery on multiple logistic regression analysis. CONCLUSION: Myocardial contrast echocardiography immediately after thrombolysis can be used for assessment of myocardial reperfusion, decision of revascularization and prediction of functional recovery.

Asessment of Myocardial Reperfusion by Myocardial Contrast Echocardiography and Its Relation to Viable Myocardium

BACKGROUND: As lack of myocardial perfusion was demonstrated on myocardial contrast echocardiography(MCE) despite angiographic documentation of reflow, patency of infarct related artery (IRA) after acute myocardial infarction(AMI) does not guarantee myocardial tissue perfusion. Myocardial enhancement on MCE is associated with myocardial perfusion and microvascular integrity. We are to assess myocardial perfusion immediately after thrombolysis and to correlate myocardial enhancement with functional recovery of postischemic dysfunctional myocardium. METHODS: MCE was performed by intracoronary injection of hand-agitated Ioxaglate in 17 consecutive AMI patients immediately after thrombolysis. Myocardial enhancement of 37 infarct segment was quantified as corrected peak videointensity(PI) by videodensitometry and the PI ratio of infarct to normal segments was used to assess myocardial reperfusion. Viable myocardium was defined as the presence of functional recovery on follow-up echocardiography. RESULTS: 1) MCE was performed in 37 segments of 17 AMI patient and functional recovery was noted in 28 segments of 12 patients on follow-up echocardiography. 2) Six infarct segments with no reflow on MCE showed severe fixed perfusion defect in thallium scan and no functional recovery in follow-up echocardiography. 3) The peak cardiac enzyme level was significantly higher in patients without functional recovery(p<0.005), but mean PI ratio(p<0.005) and patency of IRA(p<0.05) were significantly higher in patient with functional recovery. Age, sex, time to thrombolysis and stenosis of IRA were not associated with functional recovery. 4) Apical segment(p<0.01), TIMI grade 2 patency(p<0.01) and LAD territory(p<0.05) were significantly associated with nonviable myocardium, and PI ratio(p<0.001) was significantly correlated to viable myocardium. The PI ratio was the most significant predictor of myocardial functional recovery on multiple logistic regression analysis. CONCLUSION: Myocardial contrast echocardiography immediately after thrombolysis can be used for assessment of myocardial reperfusion, decision of revascularization and prediction of functional recovery.

Myocardial Contrast Echocardiography for the Assessment of Coronary Blood Flow Reserve

BACKGROUND: The assessment of coronary blood flow reserve measured by intracoronary Dopper syudy is a useful method for evaluation of functional impairment of coronary artery disease irrespective of significant anatomic stenosis. To validate the usefullness of myocardial contrast echocardiography in clinical assessment of coronary blood flow reserve, several variables analysed by myocardial contrast echocardiography were compared with coronary flow reserve measured by Dopper catheter study. METHODS: During the coronary angiography, coronary flow reserve was measured by intracoronary Dopper-tipped guidewire with coronary blood flow velocity ratio in 16 patients without angiographically significant coronary artery disease. For the measurement of coronary flow reserve, we analyzed the time-video intensity curve of short axis image of the left ventricle follwing infusion of sonicated hexabrix before and after intracoronary administration of adenosine. RESULTS: 1) There was no significiant difference or correlation between peak intensity, peak intensity ratio, washout time, half time of washout, and washout time ratio analysed by contrast echocardiography and coronary blood flow reserve measured by intracoronary Doppler study(p>0.05). But inverse correlation was observed between half time ratio of contrast washout and coronary flow reserve(r=0.63,p<0.05). 2) There was no significiant difference between non myocardial infarction group and myocardial infartion group in coronary flow reserve and half time ratio of contrast washout. 3) No significant difference was observed before and after administrantion of sonicated hexabrix in hemodynamic variables. CONCLUSION: Among several variables of myocardial contrast echocardiography analysis half time ratio of washout was significantly correlated with coronary flow reserve. Thus assesssment of coronary flow reserve with myocardial contrast echocardiography is promising method in the evaluation of dymamic coronary perfusion and myocardial viability.

A Study of Radiocontrast Media Induced Nephrotoxicity

PURPOSE: This study was aimed at determining whether tri-iodinated compounds with greater solubility and low osmolality, Na or meglumine ioxaglate(Hexabrix 320, Guerbet Lab., France) had deleterious effects on renal function after cardiac angiography for the evaluation of congenital heart disease(CHD) and determining whether correction of dehydration using iv hydration given before cardiac angiography were effective in prventing renal dysfunction. METHODS: For the study of radiocontrast media induced nephrotoxicity, 21 children with various CHDs admitted to the hospital for the evaluation of their CHDs. None of them had any evidence of renal dysfunction before study. They were devided into 2 groups, one was low-dose group(ioxaglate given, < 2.0 mL/kg) and the other one was high-dose group(>2.0 mL/kg). Renal function studies including serum creatinine(Scr), fractional excretion of sodium(FENa) and urinary beta2-microglobulin excreton(mg of beta2- microglobulin per gm creatinine) were done before and after ioxaglate administration. For the study of hydration effect on radiocontrast media induced nephrotoxicity, 9 children with CHDs were subjected. Thery were hydated with 5% D/S 1 hr before cardiac angiography using high-dose ioxaglate(> 2.0 mL/kg) and maintained on fluid therapy during the examination. Renal function studies were done before and after ioxaglate administration. Statistical analyses were done using Wilcoxon signed rank test. RESULTS: 1) Scr level and FENa were not increased significantly after administration of ioxaglate in both of low-dose and high-dose group. 2) A significant increase of urinary beta2M per creatinine excretion(mg/gm creatinine) was observed after administration of ioxaglate n the high-dose group(0.24 vs 0.57, p0.05) 3) Hydration before ioxaglate administration made urinary B2M per creatinine excretion insignificant even in patients who received high-dose ioxaglate, more than 3.0 ml/kg(0.22 vs 0.27, p>0.55). 4) Uric acid and/or calcium oxalate crystaluria appeared after ioxaglate administration, particularly in patients with dehydration. CONCLUSIONS: Ioxaglate, a low osmolality ionic dimer contrast media, could induce renal tubular dysfunction, which depended on dose used. Correction of dehydration before ioxaglate administration significantly reduced the risk of ioxaglate induced nephrotoxicity.

The Effect of Non-Ionic Contrast Media on Q-T Interval and ST-T Wave of ECG during Coronary Angiography

BACKGROUND: During coronary angiography, some electrocardiographic changes occured due to contrast media, which do life threatening influences. METHODS: We compared the electrocardiographic changes which were induced by injection of three radiopaque contrast media during selective coronary angiography in 49 patients with chest pain. One of the contrast media was high osmolar ionic(Urografin_76) and the another was low osmolar ionic(Hexabrix) and the last was non-ionic(Ioversol). Electrocardiograms were obtained before, during and after selective coronary angiography. RESULTS: The changes of S-T segment or T were decreased in non-ionic group rather than high osmolar or ionic group. And there was significant Q-Tc interval prolongation among all three groups except comparision of low osmolar ionic contrast dye and non-ionic contrast dye in left coronary angiography. CONCLUSION: Non-ionic low osmolar contrast media was safer than high osmolar or ionic contrast medial because of lesser change of Q-Tc interval during selective coronary angiography.

An Experimental Study on Tissue Reaction of Various Contrast Agents on Endometrium, Tubal Mucosa, and Peritoneum

PURPOSE: To compare the tissue reactions of various water-soluble and oil-based contrast agents on the endometrium, salpingeat mucosa, and peritoneum. MATERIALS AND METHODS: Thirty-three rabbits were used for evaluating the histologic reactions of uterine endometrium, salpinx, and peritoneum. Hysterosalpingography(HSG) was underwent in these rabbits by using Lipiodol, Hexabrix, Rayvist, Ultravist-300, Ultravist-370, and normal saline. Pathotogic results were obtained in each of the six groups from the uterine endometrium, salpingeal mucosa, and peritoneum without knowledge of the contrast agent used and time interval from HSG. RESULTS: Mild inflammations were observed in the endometrium, salpingeal mucosa, and peritoneum during the first week of HSG in all rabbits in which water-soluble contrast agents were used. Although there was no significant difference in the degree of inflammation among the groups using various contrast agents, the group with oil-based contrast agent(Lipiodoi) showed delayed absorption of contrast agent in the peritoneum, frequent intravasation, fat granuloma, peritoneal adhesion, or uterine infarction. CONCLUSION: Our results suggest that water-soluble contrast agents can be used safely for HSG, but the use of oil-based contrast agent is questionable in safety and should be avoided in patients with tubal obstruction, salpingitis, or endometritis.