Effects of nicorandil and glyceryl trinitrate on infarct size, adenosine release, and neutrophil infiltration in the dog.

OBJECTIVE: The major aim of this study was to determine if nicorandil, a potassium channel opener nitrate, produces a reduction in myocardial infarct size at a non-hypotensive dose in dogs and to determine if this effect is the result of an increase in adenosine release or reduction in neutrophil infiltration into the ischaemic area. Glyceryl trinitrate was used for purposes of comparison. METHODS: Barbitone anaesthetised dogs were subjected to 60 min of left anterior descending coronary artery occlusion followed by 3 h of reperfusion. Nicorandil (100 microgram.kg-1 bolus followed by a 10 microgram.kg-1.min-1 infusion; NC/pre group), glyceryl trinitrate (10 microgram.kg-1 bolus followed by a 1 microgram.kg-1.min-1 infusion; GTN/pre group), or an equivalent volume of saline (control group) were given intravenously 15 min before occlusion and continued to the time of reperfusion. In two other groups, nicorandil (NC/post group) or glyceryl trinitrate (GTN/post group) were given 10 min before reperfusion and continued until the end of the experiment. To measure the release of adenosine from the ischaemic region, coronary venous blood samples were collected before occlusion, during occlusion, and at various times following reperfusion. Myocardial infarct size was determined by triphenyltetrazolium chloride and transmural myocardial blood flow by radioactive microspheres. Transmural myeloperoxidase activity, an index of neutrophil infiltration, was measured in biopsies obtained from the area at risk. RESULTS: Pretreatment with nicorandil and glyceryl trinitrate caused a marked reduction in myocardial infarct size expressed as percent of the area at risk [NC/pre group, 7.8(SEM 1.6)%; GTN/pre group, 11.9(2.3)%; control group, 31.0(5.6)%]. When nicorandil and glyceryl trinitrate were given before reperfusion, both drugs still produced a significant reduction in infarct size [NC/post group, 13.8(2.0)%; GTN/post group, 18.9(4.3)%]. Coronary venous adenosine concentrations during reperfusion were significantly lower in both nicorandil and glyceryl trinitrate pretreated groups, but not in the post-treated groups. Transmural myeloperoxidase activity was significantly lower in both nicorandil treated groups. CONCLUSIONS: Pretreatment with a non-hypotensive dose of nicorandil or glyceryl trinitrate markedly reduces myocardial infarct size and adenosine release from the ischaemic-reperfused area. These agents were also effective, but to a lesser degree, when given just before reperfusion. The cardioprotective actions of nicorandil appear to be related not only to its potassium channel opening activity but also in part to its nitrate activity.

Infarct size-reducing effect of nicorandil is mediated by the KATP channel but not by its nitrate-like properties in dogs.

OBJECTIVES: We wished to determine whether the cardioprotective effect of nicorandil to reduce infarct size is blocked by glibenclamide, a selective KATP channel antagonist, or methylene blue, a nitric oxide (NO)/guanylate cyclase inhibitor, in dogs. The second aim was to determine if glyceryl trinitrate produces a cardioprotective effect in the same model and to test if this effect is blocked by methylene blue and not by glibenclamide. We also determined whether adenosine release from the ischemic-reperfused area is an accurate index of ischemic severity in the presence of these drugs. METHODS: Barbiturate-anesthetized dogs were subjected to 60 min of left anterior descending coronary artery (LAD) occlusion followed by 3 h of reperfusion. In the first three groups, either nicorandil (100 micrograms/kg bolus + 10 micrograms/kg/min), glyceryl trinitrate (10 micrograms/kg bolus + 1 microgram/kg/min) or an equivalent volume of saline was given intravenously 15 min before LAD occlusion and continued to the time of reperfusion. In the next three groups, glibenclamide (0.3 mg/kg) was administered 15 min before drug infusion. In the final three groups, methylene blue (80 microM) was given intracoronarily 5 min before nicorandil or glyceryl trinitrate and continued until 15 min following reperfusion. Coronary venous blood samples were collected at various times during ischemia and following reperfusion and the concentration of adenosine measured. RESULTS: Nicorandil produced a marked reduction in infarct size expressed as a percent of the area at risk (NC group, 12.2 +/- 3.2% vs. Control group, 25.7 +/- 4.1%, P < 0.05) and this effect was completely abolished by pretreatment with glibenclamide. However, intracoronary administration of methylene blue did not block the cardioprotective effect of nicorandil. On the other hand, glyceryl trinitrate also produced a significant reduction in infarct size (GTN group, 13.0 +/- 3.1%) and this effect was reversed by methylene blue but not by glibenclamide. Adenosine concentrations in coronary venous blood were significantly reduced after reperfusion in the groups with small infarctions as compared with the Control group. CONCLUSIONS: These results suggest that at equieffective cardioprotective doses the infarct size-reducing effect of nicorandil in dogs is mediated via opening of myocardial KATP channels and that the cardioprotective effect of glyceryl trinitrate is most likely to be mediated via activation of guanylate cyclase at a site yet to be determined.

Clinical utility of negative contrast intravascular ultrasound to evaluate plaque morphology before and after coronary interventions.

Although intravascular ultrasound (IVUS) is used for evaluation of plaque volume and lumen size as well as detection of vessel wall structures after catheter-based interventions, differentiation between the lumen and plaque structures can be difficult. This study attempted to evaluate the efficacy of negative contrast IVUS imaging for assessment of vessel wall morphology after coronary interventions. IVUS studies were performed in 67 lesions in 66 patients before and after coronary interventions. After the baseline ultrasound imaging run, warm 5% glucose solution was injected manually through the guiding catheter into the coronary artery to washout blood from the lumen to avoid speckled reflections from red blood cells (negative contrast). Quantitative measurements were obtained and plaque morphology was assessed for the presence and extent of medial dissections and intimal flaps. There was no difference in each quantitative parameter between baseline images and negative contrast images. The vessel wall boundary was clearly delineated from the lumen, which was defined as effective negative contrast in 51 of 67 lesions (76%). The baseline images revealed plaque dissection in 9 lesions (18%) and an intimal flap in 13 lesions (25%). In addition, 4 dissections (8%) and 16 intimal flaps (31%) were visualized during the infusion of negative contrast. Additional treatment was performed in 4 lesions (8%) based on the images with negative contrast. Negative contrast IVUS was more sensitive in demonstrating a plaque fracture than were baseline images. This method is useful for enhancing the diagnostic capability of IVUS imaging and may influence the decision-making process during interventional procedures.

Analysis of alcohol oxidase isozymes in gene-disrupted strains of methylotrophic yeast Pichia methanolica.

A cell-free extract of methanol-grown Pichia methanolica cells was found to contain nine alcohol oxidase (AOD) isozymes by active staining of a native polyacrylamide electrophoresis gel. Our previous study revealed that AOD in P. methanolica was encoded by two genes, MOD1 and MOD2, and the results of an experiment involving Candida boidinii as an expression host suggested that the AOD isozymes observed in P. methanolica were due to random association of Mod1p and Mod2p into an active octamer [Nakagawa et al., Yeast, 15, 1223-1230 (1999)]. This study was conducted using P. methanolica MOD1- and/or MOD2-gene disrupted strains to confirm a previous hypothesis. While the cell-free extract of the wild-type strain gave nine ladder bands, the mod1delta and mod2delta strains gave a single active AOD band corresponding to the mobilities of Mod2p and Mod1p on a native electrophoresis gel, respectively. The cell-free extract of glyceorl-grown wild-type cells gave a single band corresponding to Mod1p, showing that only MOD1 is expressed in glycerol-grown cells. While the expression of both MOD1 and MOD2 was induced by methanol, this finding and our previous observations indicated that the expression of MOD1 and MOD2 was controlled by a distinct regulatory mechanism in P. methanolica.

[Radiological evaluation of foot deformities in rheumatoid arthritis].

Deformities of the feet are common in patients with rheumatoid arthritis (RA). We investigated whether there was any correlation among forefoot deformities, flat foot or articular destruction of the midfoot and hindfoot, in 146 feet of 73 RA patients whose age varied from 26 to 81 years (mean 58.5 years). In all patients, anteroposterior (AP) and lateral radiographs of the feet with weight bearing were obtained. The hallux valgus angle (HVA), the intermetatarsal angle between the 1st and 2nd metatarsals (M 1 M 2), and the intermetatarsal angle between the 1st and 5th metatarsals (M 1 M 5) were measured on AP radiographs. On slateral radiographs, the height of the arch was measured and articular destruction of the talocalcaneal, talocrural, talonavicular, cuneonavicular and cuneometatarsal joints was measured and classified using Steinbrocker's classification. The average HVA was 23.4 degrees, the average M 1 M 2 was 11.1 degrees, and the average M 1 M 5 was 28.4 degrees. There was no correlation between forefoot deformities and flat foot. There were significant correlations between arthritic destruction of the cuneometatarsal joint and HVA, M 1 M 2 and M 1 M 5. The correlations between arthritic destruction of the cuneonavicular joint and HVA or M 1 M 2 were also significant, although weaker. Thas, we found some relationships between forefoot deformity and arthritics destruction of midfoot joints. Especially, the correlations between arthritic destruction of the cuneonavicular and cuneometatarsal joints and forefoot deformities were significant. Many radiographic methods for the assessment of RA have been reported, however, it is difficult to assess sarthritic destruction of rheumatoid feet with the existing methods. Accordingly, a new method should be established.

Determination of plasma adenosine by high-performance liquid chromatography with column switching and fluorometric detection.

A new method for the rapid determination of plasma adenosine concentrations was developed by using high-performance liquid chromatography with a column switching technique and fluorometric detection. Several "stop solutions" were used to prevent the enzymatic degradation and cellular uptake and release of adenosine in blood samples. Red blood cells and certain denatured proteins were separated by centrifugation. Subsequently, the supernatant was transferred directly into autosample vials and adenosine was reacted with chloroacetaldehyde to form a strong fluorescent, 1-N6-ethenoadenosine. The adenosine derivative was injected directly and separated on a shielded hydrophobic phase column coupled with a C18 reverse-phase column using a column switching valve. Macromolecules and other interfering substances were excluded by the shielded hydrophobic phase column and bypassed to waste. Then, the adenosine derivative and other retained compounds were switched onto the reverse-phase column for further separation and subsequently to the fluorescence detector. The system reduces the analysis time and contamination of the column and hence allows a shorter cleanup time and a longer column lifetime. Adenosine as low as 30 fmol (signal-to-noise ratio, S/N = 3) can be detected by this method. The percentage of recovery of adenosine in plasma treated with adenosine deaminase was above 90%. This method is very rapid (without tedious sample preparation) and sensitive for determining adenosine in canine blood and should prove to be useful in analyzing the effects of ischemia and reperfusion on arterial and coronary venous adenosine concentrations in blood or perfusate samples released from the ischemic or hypoxic myocardium.

Bimakalim, an ATP-sensitive potassium channel opener, mimics the effects of ischemic preconditioning to reduce infarct size, adenosine release, and neutrophil function in dogs.

BACKGROUND: The primary goal of the present study was to determine whether the infarct size-reducing effect of preconditioning is associated with an increase in adenosine release from the ischemic myocardium during a prolonged occlusion period or the subsequent reperfusion period and by a decrease in neutrophil infiltration. A second objective was to determine whether bimakalim, a KATP channel opener, mimics the effects of ischemic preconditioning. METHODS AND RESULTS: Barbital-anesthetized open-chest dogs were subjected to 60 minutes of left anterior descending coronary artery (LAD) occlusion followed by 3 hours of reperfusion. In the preconditioning group, 5 minutes of LAD occlusion followed by 10 minutes of reperfusion was elicited before the 60-minute occlusion period. In two other groups, bimakalim 1 microgram/kg bolus followed by a 0.05 micrograms.kg-1.min-1 infusion or an equivalent volume of saline was administered intravenously 15 minutes before occlusion and continued until the time of reperfusion. In a final group, bimakalim was administered 10 minutes before reperfusion and continued until the end of the experiment. To measure the release of adenosine from the ischemic region, coronary venous blood samples were collected at various times during ischemia and after reperfusion, and the concentration of adenosine was measured. Myocardial infarct size was determined by triphenyl tetrazolium chloride; transmural myocardial blood flow, by radioactive microspheres. Transmural myeloperoxidase (MPO) activity, an index of neutrophil infiltration in the area at risk, was also measured. Preconditioning produced a marked reduction in infarct size (9.8 +/- 3.0% versus 28.6 +/- 5.2% in the control group, mean +/- SEM); adenosine release at 5, 10, 15, and 30 minutes of the 3-hour reperfusion period; and transmural MPO activity in the risk area. Similarly, pretreatment with bimakalim resulted in reductions in infarct size, adenosine release, and transmural MPO activity to an extent almost identical to that of preconditioning. When bimakalim was administered 10 minutes before reperfusion, the drug also produced a significant reduction in infarct size and transmural MPO activity; however, no significant reduction in coronary venous adenosine concentrations was observed. There were no significant differences in collateral blood flow between groups. CONCLUSIONS: These results indicate that myocardial preconditioning in the canine heart produced by a short period of ischemia or a KATP channel opener is not mediated by an increase in adenosine release, as measured by coronary venous adenosine concentrations, during 60 minutes of occlusion or the initial 30 minutes of reperfusion. A significant reduction in transmural MPO activity in the ischemic area also appears to result from KATP channel activation and may play a role, at least in part, in the reduction in infarct size observed, particularly when a KATP channel opener is administered just before reperfusion.

Follow-up results of arthroscopic synovectomy for the rheumatoid knee.

Abstract Arthroscopic synovectomy (ASS) of a rheumatoid knee is performed in cases of intractable synovitis. This spares the articular cartilage, and is an effective and simple treatment for chronic knee synovitis. This retrospective study was performed to evaluate the outcome of surgical arthroscopy, and study the clinical results in detail. A total of 160 knees, in 138 patients, were assessed after a mean follow-up of 35 months. There was a statistically significant improvement in pain, synovitis, and walking ability for at least 24 months after surgery. Based on the results of our study, age, duration of rheumatoid arthritis (RA), and erythrocyte sedimentation rate (ESR) and level of C-reactive protein (CRP) at surgery were not predictors of a poor long-term outcome of ASS. However, the clinical results correlated with the Lansbury index, loss of extension of the knee joint, a modified Larsen score, and the Larsen grade of the knee joint. Of the cases studied, total knee arthroplasty (TKA) was performed in 29 knee joints. We concluded that although ASS can reduce local inflammation and delay the need for definitive replacement surgery, patients over 60 years of age who show severe radiographic changes should undergo primary TKA.

Behçet's disease with severe destructive arthritis.

Abstract Behçet's disease is a systemic disease characterized by oral aphta, genital ulcers, and ocular lesions, and arthritic manifestations also appear to be common. However, this disease rarely produces loss of function or deformity in arthritic joints. We report the case of a 52-year-old woman with Behçet's disease who had a history of recurrent oral aphta, genital ulcerations, and intestinal lesions for almost 30 years. When she was about 30 years old, she began to notice significant morning stiffness and polyarthritis, and progressive destructive arthritic changes in the bilateral fingers, wrists, and left ankle. Behçet's disease with severe destructive arthritic changes is rare, and the underlying mechanism is still unknown.

KATP channels and memory of ischemic preconditioning in dogs: synergism between adenosine and KATP channels.

Results from numerous studies have shown that there is an important link between adenosine A1 receptors and ATP-sensitive potassium (KATP) channels in mediating the cardioprotective effects of ischemic preconditioning (PC). The major aim of the present study was to determine whether occupation of A1 receptors and/or the opening of KATP channels is involved in the time delay between the PC stimulus and the prolonged ischemic insult or the "memory" of PC to reduce infarct size. Barbital sodium-anesthetized dogs were subjected to 1 h of left anterior descending coronary artery (LAD) occlusion followed by 4 h of reperfusion. Ischemic PC was elicited by 10 min of LAD occlusion followed by 1 h of reperfusion (1-h memory) before the 1-h occlusion period. Either adenosine (800 g/min), bimakalim (3 g/min), a combination of two lower doses of each agent (400 g/min of adenosine and 0.3 g/min of bimakalim), or an equivalent volume of saline was infused into the LAD for 10 min followed by a 1-h drug-free period before the 1-h ischemic insult. In another series, glibenclamide, 8-cyclopentyl-1,3-dipropylxanthine (a selective A1-receptor blocker), or PD-115199 (a nonselective adenosine-receptor antagonist) was administered 50 min after ischemic PC (10 min before the 1-h occlusion period). Infarct size (IS) was expressed as a percentage of the area at risk. PC with 1 h of reperfusion resulted in a marked reduction in IS (8.1 +/- 6.5 vs. 29.8 +/- 5.8% in control dogs). Administration of adenosine or bimakalim followed by a 1-h drug-free period had no effect on IS; however, the simultaneous administration of adenosine and bimakalim resulted in a marked decrease in IS (11.5 +/- 2.7%). One hour after ischemic PC, administration of glibenclamide blocked the protective effect of ischemic PC, whereas 8-cyclopentyl-1,3-dipropylxanthine or PD-115199 did not affect it. These results provide evidence that the opening of myocardial KATP channels may play an important role in the memory of ischemic PC in the canine heart and also suggest that adenosine and the KATP channel may have a synergistic interaction that is important for the memory phase of PC.

An ATP-sensitive potassium (KATP) channel opener, nicorandil, lowers the threshold for ischemic preconditioning in barbital-anesthetized dogs.

To determine whether the adenosine triphosphate (ATP)-sensitive potassium channel (KATP channel) opener, nicorandil, lowers the threshold for the infarct-reducing effect of preconditioning (PC), barbital-anesthetized dogs were subjected to 60-min occlusion (60'OC) of left anterior descending coronary artery (LAD) followed by 3-h reperfusion (3h-RP). At the end of the 3h-RP, heart was resected to measure infarct size. Infarct size was determined by triphenyltetrazolium chloride (TTC) staining, calculated gravimetrically and was expressed as a percent age of area at risk (AAR). Myocardial blood flow was measured by radioactive microspheres. Single 5-min LAD occlusion 10 min before 60'OC (5'PC group) markedly reduced infarct size, compared to the controls (11.8 +/- 3.7% versus 26.8 +/- 4.7%; P < 0.05). Neither 2.5-min PC (2.5'PC group), nor 2.5-min intracoronary infusion with 0.5 microgram/kg per min of nicorandil followed by a 10-min drug-free period (2.5'NC group), showed a cardioprotective effect (26.5 +/- 1.7% and 20.7 +/- 2.8%, respectively). However, when nicorandil was administered during the 2.5-min LAD occlusion period (2.5'PC + 2.5'NC group), infarct size was significantly reduced to an extent similar to that in 5'PC group (13.6 +/- 1.2%). There were no significant differences in hemodynamics, collateral circulation, or AAR between groups. These results suggest that nicorandil lowers the threshold for the infarct-reducing effect of PC in dogs by, at least in part, activation of myocardial KATP channels.

PD 81,723, an allosteric enhancer of the A1 adenosine receptor, lowers the threshold for ischemic preconditioning in dogs.

PD 81,723 (PD) acts allosterically to increase agonist binding to A1 adenosine receptors and to enhance functional A1 receptor-mediated responses in the heart and other tissues. To determine if PD lowers the threshold for ischemic preconditioning (PC), pentobarbital-anesthetized dogs were subjected to 60 minutes of left anterior descending coronary artery (LAD) occlusion and 3 hours of reperfusion. Ischemic PC was produced by either 2.5 or 5 minutes of LAD occlusion 10 minutes before the 60-minute occlusion. PD (100 micrograms/kg total dose, 5 to 50 mumol/L in coronary arterial blood) or vehicle was infused intracoronarily for 17.5 minutes before the 60-minute occlusion period in non-PC dogs or in dogs preconditioned with 2.5 minutes of ischemia. Myocardial infarct size was determined by triphenyltetrazolium staining and expressed as a percentage of the area at risk. Compared with the control group (26.3 +/- 3.6%, mean +/- SEM), infarct size was not significantly affected by 2.5 minutes of PC alone (23.4 +/- 4.2%) or by PD alone (26.5 +/- 1.7%) but was decreased by PD + PC (14.6 +/- 1.7%, P < .05) or by a longer period (5 minutes) of PC alone (12.5 +/- 3.3%). The intravenous administration of the selective antagonist of A1 adenosine receptors, 8-cyclopentyl-1,3-dipropylxanthine (1 mg/kg), or the ATP-sensitive K+ channel blocker, glibenclamide (0.3 mg/kg), for 15 minutes before PD + PC blocked the protection (23.6 +/- 2.3% or 25.9 +/- 3.3%, respectively). None of the compounds studied affected systemic hemodynamics, collateral blood flow, or AAR. To determine which subtypes of canine adenosine receptors were affected by 10 mumol/L PD, radioligand binding studies were conducted using membranes derived from COS-7 cells expressing recombinant canine receptors and agonist radioligands. PD enhanced the binding of [125I]N6-4-amino-3-iodobenzyladenosine (125I-ABA) to A1 receptors by increasing the t1/2 for dissociation by 2.18-fold, but PD had no effect on the dissociation kinetics of 125I-ABA from A3 receptors or [125I]-[2-(4-amino-3-iodo-phenyl)ethylamino] adenosine from A2A receptors. Glibenclamide at concentrations up to 10 mumol/L had no effect on the binding of radioligands to recombinant canine A1, A2A, or A3 receptors. These data suggest that PD reduces the amount of time required for ischemia to produce preconditioning by enhancing adenosine binding to its A1 receptor. Glibenclamide prevents the protection afforded by A1 receptor activation by a mechanism not involving adenosine receptor blockade.

A new sodium/hydrogen exchange inhibitor, EMD 85131, limits infarct size in dogs when administered before or after coronary artery occlusion.

Administration of inhibitors of the Na+/H+ exchanger (NHE) have been shown to produce cardioprotective effects in a number of animal models of ischemia-reperfusion injury; however, controversy still exists as to the efficacy of these agents when administered just before reperfusion. To address this question, the efficacy of several doses of a new selective NHE-1 isoform inhibitor (IC50 for inhibition of 22Na uptake in NHE-1 expressing mouse fibroblast cells = 10.4 +/- 1.0 nM), EMD 85131 (2-methyl-5-methylsulfonyl-1-(1-pyrrollyl)-benzoyl-guanidine), was tested in a canine infarct model in which the left anterior descending coronary artery was occluded for 60 min followed by 3 hr of reperfusion. EMD 85131 (0.75 or 3.0 mg/kg) was infused for 15 min before left anterior descending occlusion or 15 min before reperfusion. Infarct size was determined by use of the triphenyltetrazolium chloride histochemical stain and was expressed as a percent of the area at risk. EMD 85131 (0.75 or 3.0 mg/kg) administered before left anterior descending occlusion produced a marked (*P < .05) and dose-related reduction in IS/AAR (24.3 +/- 3.6, control; 9.3 +/- 3.4%, EMD 0.75; 6.4 +/- 2.3%, EMD 3.0). These two doses of EMD also produced significant (*P < .05) reductions in infarct size/area at risk (12.2 +/- 2.1%, EMD 0.75; 13.0 +/- 2.9%, EMD 3.0) when administered 15 min before reperfusion. These results suggest that selective NHE-1 inhibitors are able to markedly reduce infarct size when given before or during ischemia and also suggest that these compounds may have clinical utility when administered after the initiation of an ischemic insult.

Antiischemic effects of nicorandil during coronary angioplasty in humans.

The present study was undertaken on 10 patients with angina undergoing percutaneous transluminal coronary angioplasty. The angioplasty procedure consisted of two successive 30-second balloon inflations at 5 minute intervals. After the first inflation, nicorandil (0.1 mg/kg) was given intravenously over a 2-minute period. The second inflation was then performed 3 minutes after the completion of drug administration. Myocardial ischemia was measured as the magnitude of ST-segment elevation on the intracoronary electrocardiogram (intracoronary ECG) recorded from the guidewire. Nicorandil significantly reduced the magnitude of ST-segment elevation. Nicorandil did not change the heart rate-blood pressure product, nor the oxygen saturation of the blood sampled from the great cardiac vein, nor the velocity of coronary blood flow in those patients with no evidence of collaterals. These results favor the conclusion that nicorandil prolongs the intrinsic ability of cardiac myocyte to withstand oxygen deprivation. This salutary effect is possibly due to a direct cellular mechanism because nicorandil did not modify the peripheral and coronary hemodynamic parameters that govern myocardial oxygen consumption.

Intravascular ultrasound imaging in human peripheral and coronary arteries in vivo.

To determine the feasibility of intravascular ultrasound imaging in vivo, a miniaturized high frequency transducer catheter was introduced into human peripheral (n = 10) and coronary (n = 4) arteries. Cross-sectional ultrasound images were obtained from iliofemoral arteries in 10 patients using a 20 MHz transducer catheter (1.2 mm in diameter) and from coronary arteries in 4 patients using a 30 MHz transducer catheter 5 French size (Fr) following successful coronary angioplasty. Ultrasound images obtained from peripheral arteries showed a three-layered appearance (echo-reflective intima, echo-lucent media and echo-reflective adventitia) in the normal arteries. In diseased arteries, the location, amount and extent of atheromatous plaque were clearly documented. The arterial diameters measured by ultrasound closely correlated with the measurements by angiography (r = 0.91) in the peripheral arteries. Coronary angiograms obtained following balloon angioplasty revealed smooth edges at the dilatation sites without significant narrowing in all patients. However, a significant amount of residual atheromatous plaque was clearly observed on the ultrasound images at the previously dilated sites. Coronary dissection, which was identified as an echo-lucent area behind the plaque, was noted in 2 patients. Ultrasound images also revealed the presence of calcium in the plaque which was unrecognized on the angiograms in 3 patients. In addition, direct measurement of the lumen cross-sectional area was possible on the ultrasound images.(ABSTRACT TRUNCATED AT 250 WORDS)