Abnormal blood pathways in left ventricular cavity in acute myocardial infarction. Experimental observations with special reference to regional wall motion abnormality and hemostasis

To elucidate the mechanism of regional hemostasis in the left ventricular (LV) cavity during myocardial infarction, the blood pathway in LV cavity was examined with contrast echocardiography injected from the left atrium before and after coronary ligation in nine canines. Before coronary ligation, contrast echoes spread over LV cavity with one rush. After ligation, smokelike echoes indicating hemostasis were observed at the apical middle of the LV cavity in five dogs with apical akinesis and at the apical area in four dogs with apical dyskinesis. The contrast echoes did not reach the apex within one diastolic period but turned upward to the outflow tract in the middle of the cavity in all dogs. In the cardiac beats that followed, some contrast echoes spread slowly toward the apex, forming a thin layer along the posterior wall in cases with akinesis but not in cases with dyskinesis. The area separated from the blood pathway developed where the smokelike echoes had been developed. Tachycardia exaggerated the abnormality of blood pathway and widened the contrast echo-free area. The abnormal pathway of the blood in apical myocardial infarction develops hemostasis in the apex. This should be one of the mechanisms of thrombus formation in myocardial infarction.

Transient abnormal septal motion after non-surgical closure of the ductus arteriosus

Abnormal septal motion on M mode echocardiography was seen in eight of 16 patients soon after non-surgical closure of the ductus arteriosus. Ten to twenty-nine months after the procedure the abnormal septal motion had disappeared spontaneously. The cross section of the left ventricular cavity was circular both when septal motion was abnormal and when it was normal. Cross sectional echocardiography showed that there was an exaggerated anterior swinging motion of the heart in systole in patients with abnormal septal motion on the M mode recordings. The left ventricular end diastolic diameter before closure was significantly larger, and its reduction after closure was more pronounced in those with abnormal septal motion than in those without. This suggested that the abnormal septal motion was associated with relief of long standing left ventricular volume overload. It is suggested that acute shrinkage of the heart caused temporary laxity of the pericardium, and consequently more movement of the heart within the thorax. The return of normal septal motion suggests that the pericardium gradually shrank to accommodate the smaller heart.

Clinical implications of pulmonary regurgitation in healthy individuals: detection by cross sectional pulsed Doppler echocardiography

Pulsed Doppler echocardiography in healthy individuals often shows a disturbance of diastolic flow in the right ventricular outflow tract just below the pulmonary valve that suggests regurgitation. This disturbance of diastolic flow was studied in 50 healthy individuals and 40 patients with cardiopulmonary disease, some of whom had a pulmonary regurgitant murmur. Diastolic flow was disturbed in 39 of the 50 healthy individuals. In 32, cross sectional echocardiography gave a satisfactory image of the pulmonary valve. The characteristic Doppler signals usually lasted throughout diastole, were directed toward the right ventricular cavity, and gradually waned towards end diastole; they formed a spindle shaped area of abnormal signals that extended to within 10 mm of the coaptation of the pulmonary valve towards the right ventricular cavity and the pressure difference estimated from the signals by the modified Bernoulli equation seemed to be proportional to the normal retrograde transpulmonary pressure difference. In all 40 patients with cardiopulmonary disease, signals indicating pulmonary regurgitation were found whether or not a regurgitant murmur was present. When it was present, however, the spindle was longer than 20 mm and in patients with pulmonary hypertension the velocity of abnormal diastolic flow was higher than in healthy individuals. The Doppler signals registering disturbed flow in the healthy individuals resembled the signals caused by pulmonary regurgitation in the patients in terms of location, orientation, and configuration. These results show that healthy individuals usually have trivial pulmonary regurgitation. In practice the distance that the flow disturbance extends from the valve and estimated pressure difference across the valve are probably the most important variables for assessing the clinical significance of pulmonary valve regurgitation.

The computerized derivation of rate equations for enzyme reactions on the basis of the pseudo-steady-state assumption and the rapid-equilibrium assumption

A computer program is developed for the derivation of the rate equation for enzyme reactions on the basis of the pseudo-steady-state assumption and the combination of the pseudo-steady-state and the rapid-equilibrium assumptions. The program not only has an easy input method, but also can obtain a complete rate equation in itself on only one run. The usefulness of the program is demonstrated by deriving the rate equations for some typical enzyme reactions. Details of the program have been deposited as Supplementary Publication SUP 50141 (42 pages) at the British Library Lending Division, Boston Spa, Wetherby, West Yorkshire LS23 7QB, U.K., from whom copies may be obtained as indicated in Biochem. J. (1988), 249, 5.

Visualization of isolated conus artery as a major collateral pathway in patients with total left anterior descending artery occlusion

To examine the existence of isolated conus artery (ICA) as a source of collateral circulation, we selectively visualized the ICA in patients with left anterior descending coronary artery (LAD) occlusion using a no. 5 French catheter. One hundred and fifty patients with a total LAD occlusion were selected from 639 consecutive patients who had diagnostic coronary angiography during an 18-month period; the ICA was found in 45 patients. Among these patients, 30 showed the ICA as a collateral vessel supplying the distal LAD. In nine of these patients, conventional left and right coronary angiography did not reveal any other significant collateral vessels, and the distal LAD was perfused mainly by the collaterals from the ICA. No serious complications such as ventricular fibrillation or myocardial infarction occurred during these procedures. These results indicate that the selective ICA visualization is clinically important when conventional left and right angiography does not demonstrate collaterals to the obstructed LAD.

Mechanism of mitral regurgitation in patients with myocardial infarction: a study using real-time two-dimensional Doppler flow imaging and echocardiography

The aim of the present study was to elucidate the mechanisms of mitral regurgitation accompanying myocardial infarction. Severity and site of mitral regurgitation was evaluated by the real-time two-dimensional Doppler flow imaging technique in 81 patients with old myocardial infarction. The incidence of mitral regurgitation did not depend on the region of infarction. There was, however, a close relationship between the site of regurgitation and the region of infarction. In patients with mitral regurgitation spurting from the posteromedial area of the valve, the inferior wall was involved in infarction without exception and in some of these patients, the posteromedial papillary muscle was also found to be affected by myocardial infarction; in those with regurgitation spurting from the anterolateral area, the anterior wall showed asynergy. On the other hand in patients with mitral regurgitation spurting from the central area, the region of infarction varied. In these patients, however, the larger the diameter of the mitral anulus, the more severe the grade of regurgitation. The extent of asynergy was another factor related to the severity of mitral regurgitation. Both longitudinally and transversely, broad infarction leads to the enlargement of the mitral anulus. However, even if the mitral anulus is not so dilated, severe involvement of either commissural area results in severe mitral regurgitation from the same commissural side. Thus, there are two major causative factors of mitral regurgitation: (1) asynergy of the papillary muscle or the ventricle that results in mitral regurgitation located in the commissural area of the same side as asynergy, and (2) enlargement of mitral anulus, which results in regurgitation from the central area of the orifice.(ABSTRACT TRUNCATED AT 250 WORDS)

Purification and characterization of pyruvate:NADP+ oxidoreductase in Euglena gracilis

Pyruvate:NADP+ oxidoreductase was homogeneously purified from crude extract of Euglena gracilis. The Mr of the enzyme was estimated to be 309,000 by gel filtration. The enzyme migrated as a single protein band with Mr of 166,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, suggesting that the enzyme consists of two identical polypeptides. The absorption spectrum of the native enzyme exhibited maxima at 278, 380, and 430 nm, and a broad shoulder was observed around 480 nm; the maximum at 430 nm was eliminated by reduction of the enzyme with dithionite. Reduction of the enzyme with pyruvate and CoA and reoxidation with NADP+ were proved from changes of absorption spectra. The enzyme contained 2 molecules of FAD and 8 molecules of iron. It was also indicated that the enzyme was thiamine pyrophosphate-dependent. The enzyme was oxygen-sensitive, and the reaction was affected by the presence of oxygen. Pyruvate was the most active substrate, but the enzyme was slightly active for 2-oxobutyrate, 3-hydroxypyruvate, and oxalacetate, but not for glyoxylate and 2-oxoglutarate. The native electron acceptor was NADP+, whereas NAD+ was completely inactive. Methyl viologen, benzyl viologen, FAD, and FMN were utilized as artificial electron acceptors, whereas spinach and Clostridium ferredoxins were inactive. Pyruvate synthesis by reductive carboxylation of acetyl-CoA with NADPH as the electron donor occurred by the reverse reaction of the enzyme. The enzyme also catalyzed a pyruvate-CO2 exchange reaction and electron-transfer reaction from NADPH to other electron acceptors like methyl viologen. These results indicate that pyruvate:NADP+ oxidoreductase in E. gracilis is clearly distinct from either the pyruvate dehydrogenase multienzyme complex or pyruvate:ferredoxin oxidoreductase.

[Non-invasive assessment of the peak pressure gradient between the aorta and pulmonary artery in patent ductus arteriosus]

The validity of continuous wave Doppler ultrasound estimation of the peak pressure gradient between the aorta (Ao) and pulmonary artery (PA) in patients with patent ductus arteriosus (PDA) was evaluated. Ten patients, all without other anomalies, underwent cardiac catheterization and cine-angiography, and the peak pressure gradient between the Ao and PA (dP(C)) was measured during catheterization. In all cases the mean PA pressure was less than 35 mmHg. According to the angiographic findings, the patients were categorized as Group A, consisting of seven patients whose features of the ductus were wedge- or tube-like in configuration; Group B, consisting of two patients whose features were termed "orifice-like" stenosis including one with abrupt narrowing on the PA side of the ductus and the other with a short segmental ductus. Group C consisted of one patient who had a long curved segmental ductus. The maximum velocity of ductus flow was measured by continuous wave Doppler ultrasonography, and the estimated peak pressure gradient between the Ao and PA by Doppler (dP(D] was calculated using the simplified Bernoulli equation (dP = 4V2). In group A, dP(D) was overestimated compared to dP(C) in all patients by 19 to 51 mmHg (mean 34 mmHg). However, in group B, the difference between dP(D) and dP(C) was small, 5 mmHg and 7 mmHg, respectively. In group C, dP(D) was underestimated as opposed to dP(C). Thus, in the limited cases, the simplified Bernoulli equation could be used in estimating the peak pressure gradient between the Ao and PA. However, this equation leads to overestimation in many cases.(ABSTRACT TRUNCATED AT 250 WORDS)

[Noninvasive measurement of cardiac output using two-dimensional Doppler echocardiography and analysis of sources of error]

The purpose of this study was (1) to analyze the factors responsible for errors in the two-dimensional Doppler echographic measurements of cardiac output (C.O.) and (2) to establish a noninvasive method for measuring C.O. The subjects were 50 cardiac patients who had neither aortic valve disease nor intracardiac shunts. The C.O. was calculated using the following formula: C.O. (l/min) = mean flow velocity (cm/sec) x pi(aortic ring diameter/2)2 (cm2) x 60/10(3) Left ventricular ejection flow velocity was recorded in the center of the aortic ring from the apical approach. Mean velocity was calculated by integration of instantaneous mean velocity in the ejection phase divided by the cardiac cycle length, and was corrected by the Doppler incident angle. The inner diameter of the aortic ring was measured in the parasternal long-axis view at the time of the maximum ejection flow velocity. The following results were obtained: 1. Sources of error in the measurement of cardiac output. 1) Accuracy of instantaneous mean velocity calculating circuit: This calculating circuit was accurate in model experiments using pulsatile flow. 2) Effect of high-pass filter: In model circuits, application of high-pass filter overestimated flow velocity. The higher the cut-off frequency of the high-pass filter, the larger the overestimation. This was probably due to the parabolic flow velocity profile in the circuit. 3) Flow velocity profile in the aortic ring: The flow velocity profile seemed to be flat in the aortic ring except near the anterior aortic wall. Therefore, the effect of the high-pass filter was considered to be negligible in case of clinical application. 4) The effects of shift and size of sample volume: The location of sample volume relative to the aortic valve ring shifted about 7 mm during systole. However, the shift and size of sample volume seemed to have little effect on the measured C.O., because the flow velocity profile was nearly flat in the aortic ring. 5) Ultrasound beam incident angle: From a practical viewpoint, it was necessary to set an incident angle of less than 50 degrees for minimizing the error. We were able to set the angle within 50 degrees in all but one of patients. 6) Diameter of the aortic ring: Two-dimensional echographic measurement of the aortic ring diameter was not so accurate; it seemed to become a major source of error in the calculation of C.O.(ABSTRACT TRUNCATED AT 400 WORDS)

[The physiological role of the pericardium: studies based on right heart inflow dynamics in cases of left-sided pericardial defect]

Using pulsed Doppler echocardiography, the effects of postural change on the blood flow pattern in the superior vena cava and in the right ventricular inflow tract were investigated to evaluate the physiological role of the pericardium. Eight cases of left-sided pericardial defect and eight healthy subjects were examined. 1. Suppressed inflow into the right atrium during systole in left-sided pericardial defect was manifested as a reduction of the systolic wave (S) in the superior caval vein and impairment of the systolic shift of the tricuspid annulus. This suppression suggested unsatisfactory volume expansion in the right atrium due to the absence of negative intrapericardial pressure. 2. In left-sided pericardial defect, the right ventricular inflow pattern differed from the normal, most distinctly in the right lateral recumbent position, though the cardiac motion was nearly identical with that of the normal in this position. In this position, the ratio of the peak velocity of presystolic filling to that of rapid filling was increased, and the deceleration half time of rapid filling was prolonged. These findings indicated that the right ventricular rapid filling was retarded, and was compensated by the filling due to atrial contraction. It is assumed that right ventricular filling is influenced by hydrostatic pressure due to changes in posture in the absence of restriction by the pericardium. 3. It is concluded that the pericardium maintains negative intrapericardial pressure, so that each cardiac chamber is uniformly expanded for its filling, and that this function minimizes the influence of posture on cardiac hemodynamics.

Diagnosis of mitral valve perforation by real-time two-dimensional Doppler flow imaging technique

It has been difficult to diagnose mitral regurgitation due to valve perforation using either noninvasive or invasive methods, differentiating it from that resulting from incomplete coaptation of the mitral valve. This report describes three patients with infective endocarditis and mitral valve perforation, which was definitively diagnosed by the real-time two-dimensional Doppler flow imaging technique. In these three patients, B-mode echocardiography demonstrated an echo interruption on the anterior mitral leaflet. However, it was not certain whether this interruption was simply an echo dropout or indicated an interruption of the valve tissue. Doppler flow imaging then demonstrated unusual flow in the vicinity of the echo interruption, which appeared to flow from the left ventricular cavity into the left atrial cavity across the midportion of the anterior mitral valve leaflet during systole and in the opposite direction during diastole. This was interpreted as mitral valve perforation. In general, Doppler flow imaging may play a complementary role with B-mode echocardiography in cardiac diagnosis.

Purification and some properties of short chain-length specific trans-2-enoyl-CoA reductase in mitochondria of Euglena gracilis

Short chain-length specific trans-2-enoyl-CoA reductase (reductase I), which contributed to mitochondrial fatty acid synthesis, was purified about 200-fold from crude extract of mitochondria in Euglena gracilis. It had a molecular weight of 39,000, and consisted of two dissimilar subunits with molecular weights of 15,000 and 25,000. The enzyme utilized crotonyl-CoA as the most active substrate and showed negative cooperativity in the reaction with the substrate. NADH was the sole electron donor. Some divalent cations were inhibitory to the enzyme when incubated with the enzyme prior to the start of the reaction. The reductase apparently contained loosely bound FAD.

[Pulsed Doppler echocardiographic estimation of pressure gradient across a ventricular septal defect: with particular reference to potential factors of error]

The clinical validity and some problems concerning pulsed Doppler echocardiography (PD) in non-invasive estimates of pressure difference (delta P) across a ventricular septal defect were studied. The maximum velocity (max V) of the left to right shunt flow in the right ventricle was converted to delta P using the simplified Bernoulli equation: delta P = 4V2. We also used the equation: delta P = 4(V2(2) - V1(2)) to estimate the delta P in cases who had left to right shunt flows of high velocity in the left ventricle. Simulatenous recordings of both left and right ventricular pressures and PD were obtained during cardiac catheterization of 11 cases. Accurate Doppler estimates of delta P only from the maximum velocity of the left to right shunt flow in the right ventricle were impossible in nine cases whose actual delta P's were large (more than 41 mmHg) and also in eight cases whose right ventricular systolic pressure was high (either equal to or higher than left ventricular systolic pressure). Besides these 17 cases, delta P estimated by PD using the simplified Bernoulli equation in 39 cases, with pansystolic left to right shunt flows in the right ventricle, correlated well with the actually measured delta P (Y = 0.99X + 2.77, r = 0.91, p less than 0.01). The difference in the maximal instantaneous pressure gradient and Doppler delta P was considered insignificant (between 0 and 7 mmHg, mean 4 mmHg). In nine cases, the left to right shunt flows of relatively high speed (0.63 approximately 2.00 m/sec, mean 1.31 m/sec) were observed also in the left ventricle, and calculated delta P using the simplified Bernoulli equation overestimated the actually measured delta P by 2 to 16 mmHg (Y = 1.52X + 4.88, r = 0.95, p less than 0.01). However, if the delta P is estimated by using the equation, delta P = 4(V2(2) - V1(2)), without ignoring the maximum speed in the left ventricle (V1), it correlates well with the actually measured delta P (Y = 1.07X + 0.76, r = 0.98, p less than 0.01). Thus, in cases with left to right shunt flows with high speeds in the left ventricle, the equation: delta P = 4(V2(2) - V1(2)) was more accurate in estimating the delta P by pulsed Doppler echocardiography.

Right atrial flow topography in healthy subjects studied with real-time two-dimensional Doppler flow imaging technique

The pattern of normal blood flow in the right atrial cavity was studied using the newly developed real-time two-dimensional Doppler flow imaging technique as a standard reference for the Doppler diagnosis of heart diseases with intracardiac shunts at the atrial level. The study was performed primarily with use of the apical four chamber and the parasternal right ventricular inflow tract views in 21 healthy subjects. The following patterns were observed: blood from the inferior vena cava flowed up along the posterior wall of the right atrium and joined with blood from the superior vena cava in the posterocranial part of the right atrial cavity; the flow then coursed along the roof of the right atrium toward the tricuspid valve in the atrial relaxation phase. This flow was always noted along the interatrial septum in the four chamber view. During and after mid-systole of the right ventricle, additional blood flow away from the tricuspid valve appeared, moving from the valve to the central part of the right atrial cavity, that is, at the lower right of the preceding inflow; this flow was interpreted as arising from eddy currents caused by the preceding inflow. In early diastole of the right ventricle, the flow signal area along the interatrial septum and the roof of the right atrium extended into the right ventricular cavity through the tricuspid valve. In the atrial contraction phase only the blood near the tricuspid valve in the right atrial cavity appeared to flow into the right ventricular cavity. Inflow from the coronary sinus was almost undetectable.(ABSTRACT TRUNCATED AT 250 WORDS)

Semiquantitative grading of severity of mitral regurgitation by real-time two-dimensional Doppler flow imaging technique

An attempt was made to determine whether mitral regurgitation could be detected and its severity evaluated semiquantitatively by newly developed real-time two-dimensional Doppler flow imaging in 109 patients who underwent left ventriculography. In the Doppler flow imaging technique, Doppler signals due to blood flow in the cardiac chambers are processed using a high speed autocorrelation technique, so that the direction, velocity and turbulence of the intracardiac blood flow are displayed in the color-coded mode on the monochrome B-mode echocardiogram in real time. Mitral regurgitant flow was imaged as a jet spurting out from the mitral valve orifice into the left atrial cavity. It was noted that the regurgitant jet in the left atrial cavity had a variety of orientations and dynamic features when studied by the present technique. The sensitivity of the technique in the detection of mitral regurgitation was 86% as compared with that of left ventriculography. Mitral regurgitation in the false negative cases was mostly mild. On the basis of the farthest distance reached by the regurgitant flow signal from the mitral valve orifice, the severity of regurgitation was graded on a four point scale and these results were compared with those of angiography. A significant correlation (r = 0.87) was found between Doppler imaging and angiography in the evaluation of the severity of mitral regurgitation. A similar result was obtained for the evaluation based on the area covered by the regurgitant signals in the left atrial cavity. Thus, noninvasive semiquantitative evaluation by real-time two-dimensional Doppler flow imaging appears to be a promising clinical technique.

[Mitral regurgitation: detection and quantitative evaluation by two-dimensional Doppler echocardiography]

Mitral regurgitation was detected and quantitatively evaluated using two-dimensional Doppler-echocardiography. The subjects consisted of 74 cases having a variety of heart diseases, who underwent left ventriculography within one week before or after the Doppler study. Among 50 patients with mitral regurgitation confirmed by left ventriculography, the Doppler study detected mitral regurgitant flow signals in 46, for a sensitivity of 92%. Minimal mitral regurgitation in four cases could not be detected by Doppler studies. Twenty-four patients had no mitral regurgitation according to left ventriculography; all but one also had no mitral regurgitation by Doppler study, for a specificity of 96%. In one false positive case, typical mitral regurgitant flow signals were detected in an area localized within the left atrial cavity near the mitral valve orifice. The possibility remains that left ventriculography missed this minimal regurgitation. For quantitative assessment of mitral regurgitation, the following two methods were used. Three long-axis views through the lateral, middle and medial parts of the mitral valve, and a short-axis view at the level of the mitral orifice were imaged via the parasternal approach. The area where mitral regurgitant flow signals were detected was mapped on each cross-sectional echocardiogram, then the distance attained by the regurgitant flow from the mitral valve and the area covered by the regurgitant flow were determined. The maximal distance among the three long-axis views and the sum of the distances in these views was parallel to the severity of mitral regurgitation as assessed by left ventriculography.(ABSTRACT TRUNCATED AT 250 WORDS)

The physiological role of oxygen-sensitive pyruvate dehydrogenase in mitochondrial fatty acid synthesis in Euglena gracilis

In Euglena gracilis a malonyl-CoA-independent fatty acid-synthetic system, in which fatty acids are synthesized directly from acetyl-CoA as both primer and C2 donor, occurs in mitochondria, and the system contributes to the wax ester fermentation. The activity of fatty acid synthesis in the mitochondrial system was enhanced about six times when an artificial acetyl-CoA-regenerating system was present, indicating that the fatty acid-synthetic activity is controlled by the ratio of acetyl-CoA against CoA. When fatty acids were synthesized using pyruvate instead of acetyl-CoA as substrate, a high activity, about 30 times higher than that from acetyl-CoA, was found under anaerobic conditions (below 10(-5) M oxygen), while in aerobiosis fatty acids were not synthesized at all. CoA, NADH, and NADP+ were required as cofactors for fatty acid synthesis from pyruvate. It was indicated that high activity of fatty acid synthesis from pyruvate due to the high ratio of acetyl-CoA against CoA was maintained by the action of the oxygen-sensitive pyruvate dehydrogenase found in Euglena mitochondria. When [2-14C]pyruvate was fed into intact mitochondria under anaerobic conditions, radioactive fatty acids were formed in the presence of malate, which provided reducing power for the matrix.

Doppler echocardiographic features of ventricular septal rupture in myocardial infarction

Doppler echocardiography was used to evaluate the features of interventricular septal rupture in six patients with acute myocardial infarction and to substantiate the hemodynamic data and morphologic findings at surgery or autopsy. Although echocardiographic visualization of the septal rupture was obtained in only two of the six patients, unusual Doppler flow signals were detected in the apical portion of the right ventricle in all six patients. Five patients had unusual flow signals during both systole and diastole; one had such signals only during systole. The location of these unusual flow signals coincided with the site of septal rupture confirmed at surgery or autopsy. The pattern of the flow signals in one cardiac cycle was very similar to that of the pressure difference between the left and right ventricular cavities. These findings indicate that the unusual flow signals represent the left to right shunt flows resulting from septal rupture. In conclusion, Doppler echocardiography may be a very useful tool for diagnosing interventricular septal rupture easily and noninvasively in patients with acute myocardial infarction.

[Analysis of left ventricular blood flow in cases of myocardial infarction: a preliminary report]

Analysis of left ventricular blood flow in cases of myocardial infarction was attempted by two-dimensional Doppler echocardiography. Subjects consisted of 25 cases of myocardial infarction with and without ventricular aneurysm, and 15 healthy persons as controls. The Doppler recordings were made in nine areas within the left ventricular cavity from the apical approach. For healthy subjects, ejection flows were recorded in the main cavity and directed towards the aortic orifice in systole, and diastolic flows in the left ventricular inflow were recorded from the mitral orifice to the apex. However, diastolic flows toward the aortic orifice were also recorded along the interventricular septum, and interpreted as eddy currents from the apical cavity. There were no high velocity flows in the phases of isometric contraction and relaxation. In seven of 25 cases of myocardial infarction, abnormally high velocity flows of more than 30 cm/sec were recorded in the isometric relaxation phase, which were directed away from the asynergic part. In eight of the 25 patients examined, high velocity flows toward the cardiac apex were recorded at the posteroapical area in systole. Such flows have never been observed in healthy subjects. Inertia of the diastolic mitral inflow is considered to continue during systole due to impairment of contractions of the apicoinferior wall.

[Aortic flow patterns in heart diseases with left-to-right shunts from the aorta, and their clinical significance: a Doppler echocardiographic study]

Aortic flow patterns were analyzed using two-dimensional Doppler echocardiography for 15 patients with patent ductus arteriosus, seven with ruptured aneurysms of the sinus of Valsalva, two with coronary artery fistulae and for 22 healthy persons, with special reference to diastolic flow patterns. The conclusions were as follows: In healthy subjects, there was a tiny and transient reversed flow signal in early diastole followed by a slow and sustained diastolic forward flow signal. The velocity of the diastolic forward flow was slower and the duration was shorter in the lower abdominal aorta than in the upper portion. In patients with shunts from the aorta to the right-sided chambers, the early diastolic reverse flow was enhanced, and another reversed flow developed in mid- and late diastole, which was the most evident in the lower portion of the abdominal aorta. The extent of the reversed flow correlated significantly with Qp/Qs by catheterization (r = 0.73). Thus, the abdominal flow patterns in cases with left to right shunts from the aorta to the right-sided chambers of the heart provided information for estimating the size of the shunt volume. In patients with bi-directional shunts, the dominant direction of the shunt during diastole can apparently be determined by analyzing the aortic flow patterns.

Clinical applications of a new type of real-time two-dimensional Doppler flow imaging system

The clinical significance of a newly developed real-time 2-dimensional (2-D) Doppler flow imaging technique was assessed. In the instrumentation of the echocardiograph, the pulsed Doppler mechanism was incorporated in a wide-angle, phased-array system. The Doppler flow signals obtained from the cardiac chamber were processed on the basis of the autocorrelation principle. The direction, velocity and variance of the intracardiac blood flow were calculated in real time and displayed in the color-coded mode on the television screen, and were superimposed on the 2-D echocardiographic image of the heart. The technique was used in 20 healthy subjects and 100 cardiac patients. The new technique clearly visualized the whole aspect of intracardiac blood flow by the cine mode in real time; thus, the technique may be called Doppler cineangiocardiography. The mitral inflow and the aortic ejection flow were clearly demonstrated. A regurgitant jet from the valve orifices was dynamically visualized as seen in the cineangiogram. The spatial orientation and extent of the regurgitant jet were easily assessed. The jet stream through the stenotic mitral orifice was well imaged in the left ventricular cavity, showing a variety of stream directions. Intracardiac shunts in ventricular septal defect and atrial septal defect were clearly visualized. The defect could be localized on the interventricular septum on the basis of the site where the shunt flow spurted, although the echocardiographic interruption was not demonstrated in the 2-D echocardiographic image of the cardiac structure. Although some technical problems remain, our new technique greatly improves the diagnostic efficacy of ultrasound.

Occurrence of oxygen-sensitive, NADP+-dependent pyruvate dehydrogenase in mitochondria of Euglena gracilis

Pyruvate dehydrogenase found in mitochondria of Euglena gracilis was active on NADP+ but not NAD+, and FAD and methyl viologen also served as electron acceptors. For 2-oxoglutarate dehydrogenase both NAD+ and NADP+ were utilized and the ratio of its activity on NAD+ and NADP+ was about 1:5. The activity of pyruvate dehydrogenase was inhibited by pyruvate in aerobiosis, while not in anaerobiosis.

Fructose 2,6-bisphosphate, a potent regulator of carbohydrate metabolism, inhibits trehalose phosphorylase from protist Euglena gracilis

Partially purified trehalose phosphorylase (EC 2.4.1.64) from Euglena gracilis SM-ZK was inhibited by fructose 2,6-bisphosphate in both synthetic and degradative directions. Ki value for trehalose phosphorolysis was 1.2 microM and that for trehalose synthesis was 0.5 microM. Functions of fructose 2,6-bisphosphate in Euglena, particularly in the regulative mechanism of the two reserve carbohydrates, paramylon and trehalose, are discussed.

[Phonocardiographic findings of atypical patent ductus arteriosus with pulmonary hypertension]

Among 71 patients with proved patent ductus arteriosus (PDA) as a sole anomaly, 13 were diagnosed as having "atypical PDA" because of a lack of a continuous murmur. Of these, 10 had find-pulmonary hypertension and were the materials of the present study, in which the phonocardiographic findings were correlated with the findings by other techniques including pulsed Doppler echocardiography. Six cases with equal pulmonary arterial and aortic pressures showed a diastolic murmur alone. The murmur started with the pulmonic component of the second heart sound and continued throughout diastole. All cases showed inspiratory augmentation or presystolic accentuation of the diastolic murmur. Pulsed Doppler echocardiograms disclosed that the murmur was produced by pulmonary regurgitation in five of six cases and by a left-to-right shunt via the ductus plus pulmonary regurgitation in one case. A to-and-fro murmur was observed in three cases. Pulmonary artery pressure was significantly lower than that of the systemic artery in two of three cases. These hemodynamic findings and pulsed Doppler echocardiograms indicated that the murmur of the two cases was produced by both a left-to-right shunt through the ductus and pulmonary regurgitation. A systolic murmur only was seen in one case and the cause of this murmur was not clear. In four of five cases with grade IV and V murmur, division or plugging of the ductus was performed with uneventful clinical course in three and sudden death in one. On the other hand, four of five cases with grade II and III murmur showed Eisenmenger reaction and the surgery was not attempted. The second heart sound showed normal splitting in eight cases, abnormally wide splitting in one case and was single in one case.

Fatty acid synthesis in mitochondria of Euglena gracilis

A malonyl-CoA-independent fatty acid synthetic system, different from the systems in other subcellular fractions, occurred in mitochondria of Euglena gracilis. The system had ability to synthesize fatty acids directly from acetyl-CoA as both primer and C2 donor using NADH as an electron donor. Fatty acids were synthesized by reversal of beta-oxidation with the exception that enoyl-CoA reductase functioned instead of acyl-CoA dehydrogenase in degradation system. A fairly high activity of enoyl-CoA reductase was found on various enoyl-CoA substrates (C4-C12) with NADH or NADPH. Three species of enoyl-CoA reductase, distinct from each other by their chain-length specificity, were found in Euglena mitochondria, and one of them was highly specific for crotonyl-CoA. It is also discussed that the mitochondrial fatty-acid synthetic system contributes to wax ester fermentation, the anaerobic energy-generating system found in the organism.

[Noninvasive determination of the ratio of pulmonary to systemic blood flow with two-dimensional Doppler echocardiography: efficacy and limitation]

Noninvasive determination of the ratio of the pulmonary to systemic blood flow (Qp/Qs) was attempted in 31 cases with intracardiac shunt using two-dimensional pulsed Doppler echocardiography. The Qp/Qs of these cases was ranged from 0.99 to 4.55 with an average of 2.63 by cardiac catheterization. Technical problems in the measurement were also studied. Seventeen cases with no shunt were served as controls. Systemic and pulmonary flow volumes, Qp and Qs (ml/min), were calculated by the following equation: Q (ml/min) = mean flow velocity (cm/sec) X cross sectional area of the semilunar valve ring (cm2) X 60 Here, the sample volume was set in the center of the valve ring at the phase when the flow velocity attained its peak in a pulse period. The mean velocity was obtained by dividing the integration of instantaneous mean frequency in the sample volume for a pulse period by RR interval. The ultrasonic incident angle was measured on the echocardiogram. The velocity profile at the valve ring was assumed to be a plane wave. The diameter (D) of the valve ring was measured on the echocardiograms of the long-axis view of the outflow tract. To make a correction referring to the value obtained by angiocardiography, 0.22 cm was added to the value obtained on the echocardiogram (D). The cross sectional area of the valve ring was calculated according to the following formula: Cross sectional area (cm2) = pi X [(D + 0.22/2)]2 The Qp/Qs ratio by the Doppler method in the cases with no intracardiac shunt was 1.11 (S.D. = 0.21) on an average and the Qp/Qs in the cases with an intracardiac shunt was well correlated with that by catheterization (r = 0.82). These results suggested the feasibility of the clinical application of the Doppler method for noninvasive determination of Qp/Qs. In 17 cases, pulmonary and systemic flow volumes measured by the direct Fick method were compared with those by the Doppler method, respectively. Considerable differences were observed between them. There was a tendency that both pulmonary and systemic flow volumes were under-estimated by the Doppler method in cases with a large shunt.(ABSTRACT TRUNCATED AT 400 WORDS)

Doppler echocardiographic features of coronary arteriovenous fistula. Complementary roles of cross sectional echocardiography and the Doppler technique

The Doppler echocardiographic features of coronary arteriovenous fistula were investigated in eight patients with left or right coronary arteriovenous fistulas who had a continuous heart murmur in the upper precordial area and whose diagnoses were confirmed by coronary angiography. In four patients the dilated lumen of the coronary arteriovenous fistula was visualised by cross sectional echocardiography. Of these, three showed abnormal unidirectional continuous flow signals with broad velocity spectra in the fistula. Abnormal, powerful, unidirectional or bidirectional continuous Doppler signals were detected in part of the pulmonary artery in two of the eight patients, in part of the right ventricle in two, and in part of the right atrium in one; these signals were interpreted as indicating shunt flow. Although the opening of the fistula was difficult to visualise by cross sectional echocardiography, the pulsed Doppler technique helped identify the site in patients with dilatation of the coronary artery. In the remaining three patients with a small shunt no abnormal findings were obtained with cross sectional echocardiography or the Doppler technique. The size of the fistula below which no abnormal findings may be obtained by Doppler echocardiography still needs to be determined.

Analysis of blood flow in pulmonary hypertension with the pulsed Doppler flowmeter combined with cross sectional echocardiography

Blood flow patterns were analysed at nine points in the pulmonary area using the pulsed Doppler technique combined with cross-sectional echocardiography in 53 patients with heart disease and 10 healthy subjects. In subjects with a normal pulmonary artery pressure the blood flow pattern in systole showed a gradual acceleration and deceleration with a rounded summit in mid systole, designated the round type. In patients with pulmonary hypertension it showed a rapid acceleration and early deceleration with a sharp peak in early systole, designated the triangular type. The acceleration time index, defined as the ratio of the time interval from the beginning to the peak of ejection to the ejection time, showed a significant inverse correlation with mean pulmonary artery pressure. In pulmonary hypertension a prominent reverse flow occurred in the right posterior part of the pulmonary trunk during mid-systole and early diastole, indicating the presence of a vortex. Similar flow patterns were also seen in patients with idiopathic pulmonary artery dilatation. The factors responsible for the triangular type were principally the reduced capacitance and increased impedance of the pulmonary vascular tree. Those responsible for the reverse flow were the curved path of the blood flow and dilatation of the pulmonary artery.

Pulsed Doppler echocardiography in the assessment of tricuspid regurgitation

Pulsed Doppler echocardiography is a noninvasive method with high sensitivity and specificity for the assessment of tricuspid regurgitation. In patients with tricuspid regurgitation, pansystolic unusual Doppler signals are detected in the right atrial cavity, which are interpreted as tricuspid regurgitant flow signals. They distributed in a spindle-shaped area from the tricuspid orifice toward the right atrial posterior wall in parallel with the interatrial septum. The orientation of the range where the regurgitant Doppler signals are detected in the right atrial cavity shows the direction of the regurgitant jet. However, such a result is determined mainly in patients with functional tricuspid regurgitation. In regard to patients with organic tricuspid lesion, different considerations may be necessary. Semiquantitative grading of the severity of regurgitation is possible, based on the distance covered by the regurgitant signals from the tricuspid orifice. Tricuspid regurgitation is demonstrated also by contrast echocardiography. The severity is graded based on the distance reached by regurgitant curvilinear contrast echoes from the tricuspid valve in the M-mode echocardiography. If the ultrasound beam is adequately directed through the tricuspid orifice, the grade estimated by the contrast echoes are well correlated with that by the Doppler. However, if the M-mode is performed without the guide by the two-dimensional image, it may miss the most adequate beam direction for the observation, resulting in underestimating severity. The influences of tricuspid regurgitation are generally seen in the flow pattern of the major veins. However, they are more sharply reflected by the flow condition in the right atrial cavity than by the flows patterns in the major veins.

Augmentation of atrial contribution to left ventricular inflow with aging as assessed by intracardiac Doppler flowmetry

The influence of aging on the left ventricular (LV) function in diastole was investigated from the aspect of the mitral inflow pattern using 2-dimensional Doppler echocardiography. The subjects for the investigation were 69 persons who were diagnosed as healthy by a checkup examination. The peak velocity in the rapid filling phase and that in the atrial contraction phase tended to decrease and to increase with aging, respectively. However, these tendencies were not statistically significant. However, the ratio of the atrial contraction phase to the rapid filling phase showed a significant increase with aging (r = 0.82, p less than 0.001). Therefore, it is considered that the mitral flow conditions are influenced by aging. The result obtained is also interpreted to mean that the LV distensibility in early diastole is impaired with aging and that the contribution of the atrial contraction to LV filling is compensatorily augmented.

[Measurement of four chambers' volumes and ventricular masses by cardiac CT examination]

Using cardiac computed tomography (CT), the "mean" volume of each cardiac chamber and both ventricular masses were calculated from summation of a sliced volume by ungated scans obtained using rapid sequential scanning covering the whole heart. Estimation of a normal value of each chamber's volume was attempted in 20 patients with ischemic heart disease and with normal heart function. The "mean" volume of the right atrium (RAMV), right ventricle (RVMV), and left atrium (LAMV) was 22.3 +/- 6.5, 40.3 +/- 6.5 and 28.7 +/- 8.2 ml/m2, respectively. In 54 patients with valvular heart diseases, each chamber's volume obtained by CT was compared with the grade of tricuspid regurgitation (TR) estimated by ultrasonic Doppler technique or the grade of mitral regurgitation (MR) by left ventriculography (LVG). The RAMV (234 +/- 119 ml/m2) and the RVMV (101 +/- 39 ml/m2) were markedly increased in patients with severe TR (grade 3 to 4) (p less than 0.01). The LAMV (487 +/- 231 ml/m2) was also increased in patients with severe mitral regurgitation (grade 3 to 4) (p less than 0.01). In 46 patients with valvular heart diseases, the LVMV by CT was well correlated with end-diastolic volume (EDV) obtained by LVG (r = 0.92), and the LVEDVs by ECG gated CT and by LVG showed a fairly good correlation (r = 0.95). CT examination was performed before and after surgery in 17 patients with MR or TR for evaluation of the change of chamber volumes. The mean reduction ratio (MRR) of the RAMV after tricuspid annuloplasty, the LVMV after mitral valve plasty, and the LAMV after left atrial plication was 44%, 41%, and 60%, respectively.

Mitral regurgitation in hypertrophic cardiomyopathy. Non-invasive study by two dimensional Doppler echocardiography

Mitral regurgitation and its haemodynamic features were investigated non-invasively in cases of hypertrophic cardiomyopathy by means of two dimensional Doppler echocardiography. There were 28 patients, 14 of whom showed systolic anterior motion (SAM) of the mitral echo; the other 14 did not. The following results were obtained. (1) Mitral regurgitation was detected by the Doppler technique in all cases with systolic anterior motion of the mitral echo and in half of those without it. (2) Doppler signals of mitral regurgitation started immediately after the first heart sound. (3) Mitral regurgitant flow was often distributed from the entire mitral orifice over the entire or the posterior half of the left atrium in the cases with systolic anterior motion. In the cases without systolic anterior motion the regurgitation was usually localised near the mitral orifice. These features differ from those of regurgitation usually seen in rheumatic mitral valve disease and idiopathic mitral valve prolapse. (4) The Doppler technique and left ventriculography were equally efficient in detecting mitral regurgitation. (5) The early systolic component of the murmur of hypertrophic myopathy is considered to result in the main from concomitant mitral regurgitation, but not from turbulent blood flow in the left ventricular outflow tract, so that in cases with mitral regurgitation as a complication, mitral regurgitation may also contribute to the development of the midsystolic portion of the systolic murmur, while the main origin of this portion of the murmur is the left ventricular outflow obstruction.

[Diastolic filling of the right ventricle in hypertrophic cardiomyopathy studied with 2-dimensional Doppler echocardiography]

Inflow pattern at the tricuspid orifice was examined using two-dimensional Doppler echocardiography. The cases examined consisted of 24 cases of hypertrophic cardiomyopathy (HCM), 10 cases of left ventricular hypertrophy (LVH) due to hypertension or aortic valvular stenosis and 23 healthy subjects. The right ventricular inflow pattern in HCM was characterized by a slow deceleration of a rapid filling wave, an increase in the duration of an inflow due to atrial contraction and an increased ratio of the peak velocity in atrial contraction phase to that in rapid filling phase (A/R). No definite difference was noted in the right ventricular inflow pattern between HCM with and without left ventricular obstruction. The abnormalities in the right ventricular inflow pattern in LVH were similar to those in HCM. The abnormal inflow patterns in HCM and LVH suggested a reduced distensibility of the right ventricle in early diastole and the compensatory augmentation of right atrial contraction. The changes in the deceleration of the rapid filling wave and A/R ratio were significantly correlated with interventricular septal thickness (base and papillary muscle levels) in cases with LVH. This result seemed to indicate that the changes in the right ventricular inflow are mainly resulted from the influence of hypertrophy of the interventricular septum on right ventricular function. There was hypertrophy of the interventricular septum in all cases of HCM and, in addition, that of the right ventricular anterior wall in some of them. The changes in the inflow pattern in HCM are also considered to be resulted from hypertrophy of the right ventricular anterior wall and the influence of hypertrophy of the interventricular septum on right ventricular function. However, in the cases of HCM, the extent of the changes showed no significant correlation with right ventricular anterior wall thickness and interventricular septal thickness. In HCM, hypertrophy of the interventricular septum and right ventricular free wall may coexist, and ventricular hypertrophy is often nonuniform and may exhibit disarrangement in myocardial architecture. Therefore, influential factors on the right ventricular inflow are considered to be more complicated in HCM than in LVH, resulting in the absence of significant correlation to the abnormal inflow mentioned above.

Characteristics of tubulin aggregation by tubulin-binding proteins from brain and by synthetic polycations

A basic fraction from brain cytosol was found to contain two or more tubulin-binding proteins, able to induce aggregation of tubulin accompanied by hydrolysis of GTP. In some respects tubulin aggregation by the brain proteins was similar to its aggregation by polylysine. The burst of GTP hydrolysis accompanying tubulin aggregation by polylysine had the following characteristics: enhanced by salt and abolished by low temperature; not stoichiometric with the amount of tubulin precipitated and actually maximal at relatively low polylysine concentration; uncoupled temporally from aggregation, which occurred over a much shorter interval.

Analysis of the portal vein flow with two-dimensional echo-Doppler method

Blood flow of the portal vein was non-invasively studied in healthy and diseased humans with the combined use of the ultrasonic pulsed Doppler technique and real-time two-dimensional echography. In addition, the influence of food intake to the portal flow was assessed.

Localisation and direction of mitral regurgitant flow in mitral orifice studied with combined use of ultrasonic pulsed Doppler technique and two dimensional echocardiography

Regurgitant flow was analysed in 40 cases of mitral regurgitation, using combined ultrasonic pulsed Doppler technique and two dimensional echocardiography. Abnormal Doppler signals indicative of mitral regurgitant flow were detected in reference to the two dimensional image of the long axis view of the heart and the short axis view at the level of the mitral orifice. The overall direction of regurgitant flow into the left atrium was clearly seen in 28 of 40 cases, and the localisation of regurgitant flow in the mitral orifice in 38 cases. In cases with mitral valve prolapse of the anterior leaflet or posterior leaflet the regurgitant flow was directed posteriorly or anteriorly, respectively. The prolapse occurred at the anterolateral commissure or posteromedial commissure and resulted in regurgitant flow located near the anterolateral commissure or posteromedial commissure of the mitral orifice, respectively. In cases with rheumatic mitral regurgitation the regurgitant flow is usually towards the central portion of the left atrium and is sited in the mid-part of the orifice. The Doppler findings were consistent with left ventriculography and surgical findings. The ultrasonic pulsed Doppler technique combined with two dimensional echocardiography is useful for non-invasive analysis and preoperative assessment of mitral regurgitation.

Evaluation of tricuspid regurgitation by pulsed Doppler and two-dimensional echocardiography

We analyzed tricuspid regurgitation noninvasively using ultrasonic pulsed Doppler and two-dimensional echocardiography in 66 patients in whom tricuspid regurgitation was suspected from routine clinical evaluation. All of the patients also underwent right ventriculography. Ten healthy subjects served as controls. In 62 of 66 patients, the study was adequately performed. In 58 of 62 patients, pansystolic abnormal Doppler signals were detected in the right atrial cavity, and were interpreted to indicate tricuspid regurgitant flow. Two-dimensional echocardiograms in the parasternal four-chamber view demonstrated that the region in which the abnormal Doppler signals were detected was spindle-shaped and extended from the tricuspid orifice toward the right atrial posterior wall parallel to the interatrial septum. The severity of regurgitation was graded on a four-point scale, based on the distance reached by the abnormal signals from the tricuspid orifice toward the posterior wall. For comparison, the right ventriculograms were evaluated on a four-point scale similar to the Sellers classification of mitral regurgitation. The grades by the two methods matched exactly in 36 cases, differed by one level in 23 and by two levels in three. Thus, the two methods showed a good correspondence. Similar results were obtained for the grading based on the area covered by the abnormal signals. We conclude that noninvasive grading of tricuspid regurgitation by ultrasonic pulsed Doppler and two-dimensional echocardiography is practicable.

[Mitral regurgitation in hypertrophic cardiomyopathy: an analysis with two-dimensional ultrasonic Doppler echocardiography]

Intracardiac blood flow pattern in the left ventricle and left atrium was noninvasively studied by the ultrasonic pulsed Doppler flowmeter incorporated with a real-time, phased array two-dimensional echocardiography in 28 cases of hypertrophic cardiomyopathy. Emphasis was placed on the incidence and characteristic features of mitral regurgitation in this condition. The relationship of mitral regurgitation with an early systolic murmur was also studied. The results were as follows: 1) A mitral regurgitant signal by Doppler technique was noted in all cases of hypertrophic obstructive cardiomyopathy and in half of the cases of hypertrophic nonobstructive cardiomyopathy. 2) The Doppler signal of mitral regurgitation began immediately after the first heart sound. 3) The mitral regurgitant flow spread over the left atrium or directed toward the posterior half of the left atrium in the obstructive cases. However, it was localized in the vicinity of the mitral orifice in the nonobstructive cases. These findings were different from those in rheumatic mitral regurgitation or idiopathic mitral valve prolapse. 4) The findings on mitral regurgitation by the Doppler technique exhibited a satisfactory correspondence to those by left ventriculography. 5) The early part of the systolic murmur in hypertrophic cardiomyopathy was considered to be more closely related to mitral regurgitation than a turbulent forward flow due to outflow obstruction. Therefore, mitral regurgitation might have some contribution in causing a murmur in the latter period of systole.

Pulmonary regurgitation studied with the ultrasonic pulsed Doppler technique

Sixty patients with pulmonary regurgitation were studied by the pulsed Doppler technique combined with two-dimensional and M-mode echocardiography. Patients with pulmonary regurgitation had abnormal Doppler signals just below the pulmonic valve in the right ventricular outflow tract in diastole on the two-dimensional image. These signals were considered to indicate the regurgitant flow. There are two patterns of pulmonary regurgitant Doppler signals. In pulmonary hypertension, the maximal component of instantaneous flow velocity is sustained at about the same signal strength throughout diastole, but when the pulmonary arterial pressure is normal, the velocity slows down gradually from early diastole to end-diastole. Pulmonary regurgitation was detected by phonocardiography in about half the patients. In the remaining half, pulmonary regurgitant murmur could not be differentiated from aortic regurgitant murmur or was masked by coexistent aortic regurgitation or patent ductus arteriosus, whereas the Doppler technique indicated pulmonary regurgitation.

[Blood flow analysis with pulsed echo Doppler cardiography in valvular pulmonary stenosis (author's transl)]

Blood flows in the main pulmonary artery, right pulmonary artery and right ventricular outflow tract were analyzed in 11 cases of valvular pulmonary stenosis and 10 healthy subjects by pulsed echo Doppler cardiography (two-dimensional) with the parasternal and suprasternal approaches. 1) The systolic flow in the right pulmonary artery was detected in 7 cases of valvular pulmonary stenosis, in which the flow of both right and main pulmonary arteries was detected in only one case. The flows seemed to be turbulent. These abnormal signals were never detected in healthy subjects and considered to be caused by the narrowing of the pulmonic orifice. 2) Abnormal flow signals were also detected in the right ventricular outflow tract in patients of pulmonary stenosis. Their features were as follows: (1) A systolic turbulent flow was detected in a case with severe hypertrophy of the wall and narrowing of the lumen of the right ventricular outflow tract. (2) A/S ratio, which is a ratio of the peak velocity in atrial contraction (A) to the peak velocity in systole (S), was larger in cases with pulmonary stenosis than in healthy subjects (p less than 0.05). It was considered that the atrial component in the right ventricular filling was augmented in pulmonary stenosis. (3) The PEP/ET (pre-ejection period/ejection time) of the right ventricle was smaller in cases with pulmonary stenosis than in healthy subjects (p less than 0.05). The ratio exhibited a reverse correlation with the pressure gradient between the right ventricle and pulmonary artery (r = 0.74, p less than 0.025). (4) Acceleration time index, a ratio of the time interval between the upstroke and the peak velocity of ejection flow to the ejection time, as a parameter indicating the time delay of the peak velocity exhibited a significant correlation with the pressure gradient between the right ventricle and pulmonary artery (r = 0.67, p less than 0.05). (5) No correspondence was revealed between the time interval of Q-peak velocity in systole and that of Q-peak intensity of the murmur during systole. It was remained to be clarified.

[Evaluation of tricuspid regurgitation by the ultrasonic pulsed Doppler technique from a transcutaneous approach (author's transl)]

Severity of tricuspid regurgitation was assessed by using a combined system of the ultrasonic pulsed Doppler technique and two-dimensional echocardiography from a transcutaneous approach. The study group comprised 47 patients with various heart diseases, who were clinically presumed to have tricuspid regurgitation, and 10 healthy subjects. 1) Pansystolic abnormal flow signal was detected in an area from the tricuspid valve into the right atrial cavity in 43 patients including 8 patients without definitive signs of tricuspid regurgitation. Such abnormal flow had never been detected in healthy subjects and was considered to represent tricuspid regurgitant flow. Tricuspid regurgitant flow usually exhibited a wide band spectrum of velocity component indicating a disturbed flow. In 4 patients with clinical signs of severe tricuspid regurgitation, a laminar flow was detected in the right atrial cavity, which was considered to indicate a regurgitant jet in the central part of tricuspid regurgitant flow. 2) The area where tricuspid regurgitant flow was detected was interpreted as revealing the main direction and spread of tricuspid regurgitant flow. Based on this finding, severity of TR was classified into 4 grades by the assessment on the basis of the distance reached by tricuspid regurgitant flow in the right atrium. Severity of tricuspid regurgitation was also classified into 4 grades by right ventriculography. The grade of tricuspid regurgitation assessed by Doppler technique was nearly consistent with that assessed by right ventriculography. Severity of tricuspid regurgitation was also classified into 4 grades on the basis of the extent of the area where the regurgitant flow spread, and nearly the same results were obtained as those described above. 3) Thus, the combined use of Doppler flowmetry and two-dimensional echocardiography proved to be useful for detecting tricuspid regurgitant flow and assessing the severity of tricuspid regurgitation.