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Biomedical subjects

T Wakatsuki

Publications and source records attributed to T Wakatsuki.

At least 37 records · Page 2Linked to original sources
PubMed2000

Use of angiotensin II stress pulsed tissue Doppler imaging to evaluate regional left ventricular contractility in patients with hypertrophic cardiomyopathy.

There is controversy concerning whether contract-ility in the nonhypertrophied region of the left ventricular (LV) wall is impaired or normal in patients with hypertrophic cardiomyopathy (HCM). Global LV systolic function decreases with increases in afterload in this disease. This study was performed to identify abnormalities in regional LV contractility along the long and short axes in the setting of HCM with the use of angiotensin II (AT-II) stress pulsed tissue Doppler imaging (PTDI). Angiotensin II was administered intravenously to patients with asymmetric septal hypertrophy (HCM group, n = 21) and age-matched normal volunteers (N group, n = 12). We then measured the percent LV fractional shortening (%FS) and end-systolic circumferential LV wall stress by M-mode echocardiography, LV ejection fraction (LVEF) by 2-dimensional echocardiography, and time-velocity integral (TVI) of LV outflow velocity by pulsed Doppler echocardiography. The peak first and second systolic LV wall motion velocities along the long (L-Sw(1) and L-Sw(2)) and short (S-Sw(1) and S-Sw(2)) axes were measured in the LV posterior wall and ventricular septum with the use of PTDI. The end-systolic circumferential LV wall stress at baseline was significantly lower in the HCM group. The L-Sw(1) and L-Sw(2) for the posterior wall were significantly lower in the HCM group, but the S-Sw(1) and S-Sw(2) for the posterior wall and ventricular septum were similar in the two groups. The %FS, LVEF, TVI, and systolic PTDI variables along both axes for the posterior wall decreased significantly, and end-systolic circumferential LV wall stress increased significantly at AT-II doses of 0.005 or 0.010 microg/kg per minute in the HCM group. No significant changes were found in either group in the systolic PTDI variables (except for L-Sw(1)) for the ventricular septum with AT-II infusion. Contractility along the long and short axes of the nonhypertrophied LV wall is easily impaired with increases in afterload in patients with HCM, resulting in a decrease in global LV systolic function. We found AT-II stress PTDI to be a safe and useful technique for evaluating the regional LV systolic function in this disease.

Analysis of Variance↗
PubMed2000

Circulating adhesion molecules and severity of coronary atherosclerosis.

BACKGROUND: Circulating leukocytes are recruited at atherosclerotic sites through a family of adhesion molecules. Circulating forms of adhesion molecules in peripheral blood can be quantified now. OBJECTIVE: To evaluate the relationship between circulating adhesion molecules and severity of coronary atherosclerosis. METHODS: Subjects included 81 patients undergoing diagnostic coronary angiography, 12 of whom had normal coronary arteries (control group). The remaining 69 patients with demonstrable coronary atherosclerosis were divided into two groups by use of Gensini scores, namely mild atherosclerosis (n = 36, Gensini score 1-20) and severe atherosclerosis (n = 33, Gensini score > 20). Serum levels of circulating intercellular adhesion molecule-1 (ICAM-1), vascular cellular adhesion molecule-1 (VCAM-1), and E-selectin of groups measured before angiography were compared. RESULTS: Circulating levels of ICAM-1 in members of mild and severe atherosclerosis groups were significantly higher than those in members of the control group, whereas there was no significant difference among circulating levels of VCAM-1 in members of the three groups. Circulating levels of E-selectin in members of the mild atherosclerosis group were significantly higher than those in members of the severe atherosclerosis and control groups. CONCLUSIONS: These findings suggest that E-selectin is related to the early stage, and ICAM-1 is related to the advanced stage, of coronary atherosclerosis. With progression of atherosclerosis, one-step adhesion by ICAM-1 could become more important than multistep adhesion involving E-selectin, ICAM-1, and VCAM-1. These molecules may serve as markers for severity of coronary atherosclerosis.

Adult↗
PubMed2000

Leukocyte counts and concentrations of soluble adhesion molecules as predictors of coronary atherosclerosis.

BACKGROUND: Authors of recent studies have reported that there is a relationship between level of adhesion molecules and atherosclerosis. In an animal study it was demonstrated that there is an interaction between adhesion molecules and leukocytes in atherosclerotic tissue. OBJECTIVE: To study the relationships between coronary-artery atherosclerosis and both differential blood-leukocyte count and concentrations of soluble adhesion molecules in patients with and without coronary artery disease (CAD). METHODS: Our subjects were 168 patients who underwent diagnostic coronary angiography. Forty-eight patients had normal coronary angiograms (control group), and 120 patients had significant coronary-artery stenoses (diameter stenosis > 70%) in at least one major coronary-artery branch (CAD group). Total and differential blood-leukocyte counts, and concentrations of soluble intercellular adhesion molecule-1 (sICAM-1) and vascular cell adhesion molecule-1 (sVCAM-1) were assayed prior to angiography. RESULTS: Monocyte counts for patients in the CAD group were significantly greater than those for patients in the control group (366 +/- 99 versus 258 +/- 44/microl, P < 0.0001), as were the sICAM-1 concentrations (272 +/- 52 versus 203 +/- 24 ng/ml, P < 0.0001). The mean concentrations of sVCAM-1 in members of the two groups were the same (671 +/- 138 versus 668 +/- 97 ng/ml, P=0.4). There was a higher incidence of significant coronary-artery stenosis among patients with both a high monocyte count and a high concentration of sICAM-1 (> or = mean + SD) than there was among patients with a low monocyte count and a low concentration of sICAM-1 (> or = mean - SD; 100 versus 25%, P < 0.0001). CONCLUSIONS: Higher levels both of monocyte counts and of serum concentrations of ICAM-1 may serve as markers for coronary atherosclerosis.

Biomarkers↗
PubMed2000

Patient with atrioventricular node reentrant tachycardia with eccentric retrograde left-sided activation: treatment with radiofrequency catheter ablation.

We describe a patient with supraventricular tachycardia with triple atrioventricular (AV) node pathway physiology. A discontinuous curve was present in the antegrade AV nodal function curves. During right ventricular pacing, the earliest retrograde atrial activation was recorded at the left-sided coronary sinus electrode. The retrograde ventricular-atrial interval was long and had decremental conduction. We induced a slow-slow AV node reentrant tachycardia (AVNRT) with eccentric retrograde left-sided activation. After slow pathway ablation, dual AV nodal pathway physiology was present. AVNRT with eccentric retrograde left-sided activation is relatively rare, and our findings suggest that eccentric retrograde left-sided atrial inputs consist partially of a slow pathway and disappear with slow pathway ablation.

Atrial Function, Left↗
PubMed2000

Sjögren's syndrome with primary biliary cirrhosis, complicated by transverse myelitis and malignant lymphoma.

A 53-year-old woman with Sjögren's syndrome (SS) and primary biliary cirrhosis (PBC) complicated by transverse myelitis (TM) and malignant lymphoma (ML) is reported. TM has been described only in seven cases of primary SS, including three with PBC and four without PBC. The features of SS associated with PBC and complicated by TM were less typical compared with those seen in SS without PBC complicated by TM. This case is the first report of a case with SS, PBC, TM and ML. SS in association with PBC is, in general, overlooked, but such cases must be investigated with great caution for extraglandular complications.

Abdomen↗
PubMed2000

Hepatopulmonary syndrome-discussion of cardiopulmonary parameters.

We report a 70-year-old man with hepatopulmonary syndrome (HPS) in C liver cirrhosis. Hypoxemia worsened markedly, especially on exertion, while the hepatic function was clinically stable. Contrast echocardiography, 99mTc macroaggregated albumin (99mTcMAA) lung scan, and pulmonary angiography were performed. The findings suggested the presence of both intrapulmonary vascular dilatation and substantial right-to-left shunt. The contribution of intrapulmonary vascular abnormalities in patients with severe liver cirrhosis without abnormal chest radiography and spirometry tests when marked hypoxemia is present should be investigated.

Aged↗
PubMed1999

Serial analysis of gene expression in HIV-1-infected T cell lines.

The gene expression profile of the HIV-1 infection state was analyzed in the human T cell line MOLT-4. Using the serial analysis of gene expression (SAGE) method, a total of 142¿ omitted¿603 SAGE tags were sequenced and identified, representing 43¿ omitted¿581 unique mRNA species. Comparison of expression patterns revealed that 53 cellular genes were differentially expressed upon HIV-1 infection. Northern blot and RT-PCR analyses confirmed the altered expression of the genes in both MOLT-4 and MT-4 cells. Up-regulated genes were mainly composed of transcription factors and genes related to T cell activation, whereas down-regulated genes were comprised of mitochondrial proteins, actin-related factors and translational factors. These findings indicate that persistent T cell activation, which may accelerate HIV-1 replication, and the disruption of cellular housekeeping genes including those involved in anti-apoptotic systems, may play an important role in HIV-1-induced pathogenesis.

Apoptosis↗
PubMed1999

Identification and characterization of genes associated with human hepatocellular carcinogenesis.

Eight cDNAs encoding galectin 4 (Gal-4), UGT2B4 (UDP-glucuronosyltransferase), ribosomal phosphoprotein P0 (rpP0), dek, insulin-like growth factor binding protein (IGFBP) 1, vitronectin, retinoic acid-induced gene E (RIG-E), and CYP3A4 (cytochrome P450 nifedipine oxidase) were identified as differentially expressed genes between human hepatocellular carcinoma (HCC) and matched nontumorous liver tissues. Higher levels of UGT2B4, rpP0, dek, vitronectin, Gal-4, and IGFBP-1 mRNAs combined with a lower level of RIG-E mRNA were observed in at least four of five primary HCCs compared to matched nontumorous liver tissues. Furthermore, a pathological study suggested that the levels of UGT2B4, rpP0, dek, and vitronectin increased and the level of RIG-E decreased with the histological grading. On the other hand, the expression of CYP3A4 mRNA and CYP3A7 (P-450 Fla) mRNA, a transcript found in the fetus and highly homologous to CYP3A4, was higher in all nontumorous liver and some of the carcinoma tissues from five HCC patients, whereas it was significantly lower in normal liver tissues from two non-HCC patients. The examination using HCC cell lines HuH-7 and HepG2 under different growth conditions suggested that the expression of dek mRNA was growth-associated. In contrast, the expression of Gal-4, UGT2B4, IGFBP-1, and RIG-E mRNAs was regulated in a cell density-dependent manner: the levels of Gal-4, UGT2B4, and IGFBP-1 were undetectably low, whereas the level of RIG-E was high in rapidly proliferating, subconfluent HCC cells in 10% serum; however, the expression levels were reversed in dense, overcrowded cultures. In addition, IGFBP-1 and Gal-4 mRNAs were also induced by reducing the serum concentration to 0.1%. We also demonstrated that sodium butyrate, an inducer of differentiation, up-regulated and down-regulated RIG-E and dek mRNAs, respectively, in a dose-dependent manner in HuH-7 cells, supporting, in part, our pathological observation. In summary, therefore, high expression of Gal-4, UGT2B4, rpP0, dek, IGFBP-1, and vitronectin, together with low expression of RIG-E, was correlated with the malignant potential of HCC. CYP3A4 and CYP3A7 could be induced in HCC-bearing livers. These transcripts are differentially regulated depending on cell-cell contact, serum growth factors, growth and differentiation status, and/or other mechanisms in premalignant and malignant liver cells.

Antigens, Surface↗
PubMed1999

Serial analysis of gene expression in a microglial cell line.

We used the serial analysis of gene expression (SAGE) method to systematically analyze transcripts present in a microglial cell line. Over 10,000 SAGE tags were sequenced, and shown to represent 6,013 unique transcripts. Among the diverse transcripts that had not been previously detected in microglia were those for cytokines such as endothelial monocyte-activating polypeptide I (EMAP I), and for cell surface antigens, including adhesion molecules such as CD9, CD53, CD107a, CD147, CD162 and mast cell high affinity IgE receptor. In addition, we detected transcripts that were characteristic of hematopoietic cells or mesodermal structures, such as E3 protein, A1, EN-7, B94, and ufo. Furthermore, the profile contained a transcript, Hn1, that is important in hematopoietic cells and neurological development (Tang et al. Mamm Genome 8:695-696, 1997), suggesting the probable neural differentiation of microglia from the hematopoietic system in development. Messenger RNA expression of these genes was confirmed by RT-PCR in primary cultures of microglia. Significantly, this is the first systematic profiling of the genes expressed in a microglial cell line. The identification and further characterization of the genes described here should provide potential new targets for the study of microglial biology.

Animals↗
PubMed1999

Collagen receptor control of epithelial morphogenesis and cell cycle progression.

To define the unique contributions of the alpha subunit cytoplasmic tails of the alpha(1)beta(1) and alpha(2)beta(1) integrin to epithelial differentiation and branching morphogenesis, a variant NMuMG cell line lacking alpha(1)beta(1) and alpha(2)beta(1) integrin expression was stably transfected with the full-length alpha(2) integrin subunit cDNA (X2C2), chimeric cDNA consisting of the extracellular and transmembrane domains of the alpha(2) subunit and the cytoplasmic domain of the alpha(1) subunit (X2C1), or alpha(2) cDNA truncated after the GFFKR sequence (X2C0). The X2C2 and X2C1 transfectants effectively adhered, spread, and formed focal adhesion complexes on type I collagen matrices. The X2C0 transfectants were less adherent to low concentrations of type I collagen, spread less well, and formed poorly defined focal adhesion complexes in comparison to the X2C2 and X2C1 transfectants. The X2C2 and X2C1 transfectants but not the X2C0 transfectants proliferated on collagen substrates. Only the X2C2 transfectants developed elongate branches and tubules in three-dimensional collagen gels and migrated on type I collagen. These findings suggest a unique role for the alpha(2) integrin cytoplasmic domain in postligand binding events and cooperative interactions with growth factors that mediate epithelial differentiation and branching morphogenesis. Either intact alpha(1) or alpha(2) integrin subunit cytoplasmic domain can promote cell cycle progression.

Animals↗
PubMed1999

Effect of aging on diastolic left ventricular myocardial velocities measured by pulsed tissue Doppler imaging in healthy subjects.

We evaluated the effect of aging on diastolic left ventricular (LV) wall motion velocity in 80 healthy persons with the use of pulsed tissue Doppler imaging. The wall motion velocity patterns were recorded at the middle regions of the LV posterior wall and ventricular septum in the parasternal (along the short axis) and apical (along the long axis) LV long-axis views. In the posterior wall, the peak early diastolic wall motion velocities (Ews) along both axes correlated inversely with age (long axis: r = -0.61, P <. 0001; short axis: r = -0.55, P <.0001), and the peak atrial systolic wall motion velocities(Aws) along both axes correlated directly with age (long axis: r = 0.59, P <.0001; short axis: r = 0.65, P <.0001). In the ventricular septum, the Ew along the long axis correlated inversely with age (r = -0.51, P <.0001), and the Aws along both axes correlated directly with age (long axis: r = 0.57, P <.0001; short axis: r = 0.53, P <.0001). The Ews along both axes at the posterior wall correlated directly with the peak early diastolic transmitral flow velocity. The Aws along both axes at the ventricular septum and posterior wall correlated directly with the peak atrial systolic transmitral flow velocity. The times from the second heart sound to the peak of the early diastolic waves of the ventricular septum and posterior wall along both axes significantly increased with age. The times from the aortic component of the second heart sound to the peak of the early diastolic motion velocities along both axes were significantly longer at the ventricular septum than at the posterior wall. Pulsed tissue Doppler imaging may be useful for evaluating the effect of aging on diastolic LV function in healthy persons.

Aging↗
PubMed1999

Pulsed tissue Doppler imaging of left ventricular systolic and diastolic wall motion velocities to evaluate differences between long and short axes in healthy subjects.

Our objective was to evaluate in healthy subjects the left ventricular (LV) wall motion velocities along the long and short axes by means of pulsed tissue Doppler imaging (TDI) to clarify the differences in the LV systolic and diastolic function between both axes. Wall motion velocities were recorded at the mid-wall portion of the middle site of the LV posterior wall in the parasternal long-axis view, and at the subendocardial portion of the middle site of the LV posterior wall in the apical long-axis view by pulsed TDI in 35 healthy subjects (mean age 26 +/- 10 years, mean heart rate 72 +/- 7 bpm). In all subjects, the LV pressure curve, its first derivative (dP/dt), the LV wall motion velocity, the phonocardiogram, and the electrocardiogram were simultaneously recorded. The systolic wave of the LV posterior wall motion velocity exhibited 2 peaks: the first and second systolic waves (Swl and Sw2, respectively). The diastolic wave also exhibited 2 peaks, the early diastolic and atrial systolic waves. The Swl along the long axis was greater than either the Sw1 and Sw2 along the short axis or the Sw2 along the long axis. The peak Sw1 along the long axis coincided with the peak dP/dt and was slightly earlier than the peak Swl along the short axis. The onset of Sw1 along the long axis coincided with the onset of the first heart sound. The Sw2 along the short axis was greater than that along the long axis. The early diastolic wave along the short axis was greater than that along the long axis, whereas the atrial systolic wave along the long axis was greater than that along the short axis. Thus, in healthy subjects, shortening of the longitudinal fibers predominated over that of the circumferential fibers during early systole, whereas shortening of the circumferential fibers predominated over the longitudinal fibers during the ejection phase. During diastole, the circumferential fibers predominated in the LV wall expansion at early diastole, whereas the longitudinal fibers predominated at atrial systole. In conclusion, pulsed TDI provided information that is useful in understanding the characteristics of LV wall motion along the long and short axes.

Adult↗
PubMed1999

Effect of an acute increase in afterload on left ventricular regional wall motion velocity in healthy subjects.

We recorded left ventricular (LV) wall motion velocities before and after angiotensin II infusion by pulsed tissue Doppler imaging in 20 healthy subjects, and evaluated the responses of systolic and diastolic LV function along the long and short axes during an acute increase in afterload. Angiotensin II was administered intravenously to obtain a 30% increase in mean blood pressure. After angiotensin II infusion, LV end-systolic dimension and end-systolic circumferential wall stress increased significantly, and the percentage of LV fractional shortening decreased significantly. Peak first systolic LV wall motion velocity (Sw1 ) along the long axis decreased markedly compared with that along the short axis, and peak second systolic LV wall motion velocity (Sw2 ) along the short axis decreased significantly compared with that along the long axis. Early diastolic LV wall motion velocities along both the long and short axes decreased significantly, whereas atrial systolic LV wall motion velocity did not change. In conclusion, an acute increase in afterload caused a significant decrease in longitudinal fiber shortening during the isovolumic contraction phase (Sw1 along the long axis), circumferential fiber shortening during the ejection phase (Sw2 along the short axis), and LV relaxation during early diastole (early diastolic LV wall motion velocities along both axes) in healthy subjects. Pulsed tissue Doppler imaging may be useful for detecting the effect of various loading conditions on LV wall motion velocities along the long and short axes.

Adult↗
PubMed1999

Left ventricular systolic wall motion velocities along the long and short axes measured by pulsed tissue Doppler imaging in patients with atrial fibrillation.

Pulsed tissue Doppler imaging was performed to measure systolic left ventricular (LV) posterior wall motion velocity along the long and short axes and to evaluate the relationships between the systolic variables and the maximum first derivative (peak dP/dt) of the LV pressure curve and the 2 preceding R-R intervals in 39 patients with atrial fibrillation (AF). The study group consisted of 22 patients with AF only, 17 patients with dilated or ischemic cardiomyopathy and AF, and 25 healthy control subjects in sinus rhythm. The systolic component of the LV posterior wall motion velocity was divided into the first (Sw1) and second (Sw2 ) systolic waves. The peak Sw1 along the long axis was greater than either that along the short axis or the peak Sw2s along the long and short axes in the control and AF-only groups. The peak Sw1 along the long axis was lower in the AF-only group than in the control group, and those along the short and long axes were lower in the dilated AF group than in the other groups. The peak Sw1 almost coincided with the peak dP/dt. The peak Sw1 along the long axis correlated closely with the peak dP/dt, and the ratio of the preceding R-R interval to the interval before the preceding ("prepreceding") R-R interval in both AF groups, particularly in the dilated AF group, and the slopes of their relationships were steeper in the dilated AF group than in the AF-only group. The peak Sw2 along the short axis was greater than that along the long axis in the control and AF-only groups. The peak Sw2 along the long axis was lower in the AF-only group than in the control group, and those along the short and long axes were lower in the dilated AF group than in the other groups. The peak dP/dt was lower and the LV end-diastolic pressure was higher in the dilated AF group than in the other groups. In conclusion, peak Sw1 along the long axis is useful for the evaluation of isovolumic myocardial LV contractility, and the interval-force relation and the Frank-Starling mechanism are important factors of beat-to-beat variability in systolic LV function in patients with AF.

Atrial Fibrillation↗
PubMed1999

Evaluation of left ventricular contraction abnormalities in patients with dilated cardiomyopathy with the use of pulsed tissue Doppler imaging.

The left ventricular (LV) systolic wave, as recorded by pulsed tissue Doppler imaging, usually consists of 2 components (Sw(1) and Sw(2)). However, the clinical significance of these waves has not been studied in patients with dilated cardiomyopathy (DCM) and sinus rhythm. We studied 25 patients with DCM (DCM group) and 22 age-matched normal subjects (control group). The LV posterior wall motion velocities along the short and long axes were recorded by pulsed tissue Doppler imaging, and the peak velocities of the Sw(1) and Sw(2) and the times from the electrocardiographic Q wave to the peak Sw(1) and Sw(2) (Q-Sw(1) and Q-Sw(2), respectively) were determined. In all patients cardiac catheterization was performed immediately after the noninvasive examination, and the LV end-diastolic pressure and peak dP/dt were determined. The LV end-diastolic pressure and peak dP/dt were significantly greater and lower, respectively, in the DCM group. The peak Sw(1) along the long axis was significantly greater than Sw(1) and Sw(2) along the short axis and Sw(2) along the long axis in the control group. The peak Sw(1) and Sw(2) along the long and short axes were all significantly lower in the DCM group than in the control group. The Q-Sw(1) along the long axis was significantly shorter than that along the short axis, whereas no significant difference was seen in the Q-Sw(2) in either axis in any patient. The Q-Sw(1) and Q-Sw(2) along both axes were significantly longer in the DCM group than in the control group. All systolic pulsed tissue Doppler imaging variables, particularly the peak Sw(1) along the long axis, correlated well with the peak dP/dt in all patients. LV contractility along both the short and long axes is commonly impaired in patients with DCM. In particular, peak Sw(1) along the long axis is a useful parameter for evaluating LV myocardial contractility during isovolumic contraction.

Blood Flow Velocity↗
PubMed1999

Influence of aging on systolic left ventricular wall motion velocities along the long and short axes in clinically normal patients determined by pulsed tissue doppler imaging.

Our objective was to evaluate the influence of aging on left ventricular (LV) regional systolic function along the long and short axes in clinically normal patients. We recorded LV wall motion velocity patterns at the mid-wall portion of the middle of the LV posterior wall in the parasternal long-axis view (short-axis direction) and at the endocardial portion of the middle of the LV posterior wall in the apical long-axis view (long-axis direction) with pulsed tissue Doppler imaging in 80 normal patients (age range 15 to 78 years). In all patients the LV pressure curve and its first derivative (dP/dt) were recorded. The systolic wave of the LV posterior wall motion velocity pattern exhibited 2 peaks, the first (Sw(1)) and second (Sw(2)) systolic waves. No significant changes were seen with aging in the percent LV fractional shortening determined by M-mode echocardiography, LV ejection fraction determined by left ventriculography, the peak Sw(1) and Sw(2) along the short axis, the peak Sw(2) along the long axis, and the peak dP/dt. The peak Sw(1) along the long axis correlated inversely with age (P <.0001) but did not correlate significantly with the peak dP/dt. These results suggest that shortening of the longitudinal fibers in early systole is impaired with increased age in healthy individuals. This impairment results in insufficient spherical change in the LV cavity, although global LV pump function and myocardial contractility are maintained.

Adolescent↗
PubMed1999

Coronary flow velocity immediately after reperfusion reflects myocardial microcirculation in canine models of acute myocardial infarction.

Recent reports indicate that the coronary microcirculation is sometimes injured, despite successful reperfusion in acute myocardial infarction (AMI). However, it is difficult to evaluate the coronary microcirculation immediately after reperfusion by using only angiography. The purpose of this study was to examine the relationship between the pattern of coronary blood flow velocity and myocardial microcirculatory injury immediately after reperfusion in AMI. The authors recorded the left circumflex coronary flow velocity by using the Doppler guide wire method 10 minutes after reperfusion in a canine model of AMI. In addition, myocardial contrast echocardiography was performed with the injection of contrast medium into the left circumflex coronary artery before clamping of the coronary artery and 15 minutes after release of the clamp. From these images, the ratio of the normalized gray-level postreperfusion to preclamping in the contrast-enhanced area was determined. It was compared with coronary flow velocity variables. In the 10 dogs with a diastolic-to-systolic velocity ratio (DSVR) < 4.0, this velocity ratio 10 minutes after reperfusion correlated positively (r = 0.75, p < 0.01) with the normalized gray-level ratio. However, the remaining three dogs with a DSVR > or = 4.0 markedly deviated from this pattern. Coronary flow velocities in the three dogs were characterized by a greater decrease in systolic flow velocity and occurrence of early systolic retrograde flow. Myocardial contrast echocardiographic images in these three dogs demonstrated a lower normalized gray-level ratio. In conclusion, the coronary flow velocity pattern immediately after reperfusion may reflect myocardial microcirculatory injury.

Albumins↗