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Biomedical subjects

S Beppu

Publications and source records attributed to S Beppu.

At least 109 records · Page 6Linked to original sources

Mechanism of systolic anterior motion of mitral valve and site of intraventricular pressure gradient in hypertrophic obstructive cardiomyopathy.

The mechanism of systolic anterior motion of the mitral valve and the localisation of the intraventricular pressure gradient were determined in 15 cases of hypertrophic obstructive cardiomyopathy by the combined use of real time two dimensional echocardiography and intracardiac manometry. We arrived at the following conclusions. The systolic anterior motion of the mitral echo in the M-mode echocardiogram can be classified into two types, I and II, based on two dimensional echocardiographic findings. In type I, the echo sources of systolic anterior motion are the anteriorly shifted mitral chordae and, in part, the papillary muscles. The intraventricular pressure gradient occurs at the level of the tip of the papillary muscle. The suprapapillary part of the outflow tract and the inflow part show a low pressure, while the apical cavity shows a high pressure. In type II, the echo sources of systolic anterior motion are the anterior and posterior mitral leaflets which are oriented in such a way as to obstruct the outflow tract. The pressure gradient occurs at the level of the anterior and posterior mitral leaflets. The inflow tract and the outflow tract just below the mitral leaflets show a high pressure, in contrast to type I systolic anterior motion. The inappropriate and maloriented papillary muscles play an essential role in causing both types of systolic anterior motion and outflow obstruction. The direction of the axis of the papillary muscle is changed in late systole, moving its tip away from the interventricular septum, resulting in a simultaneous reduction in systolic anterior motion.

Adult↗

Supravalvular aortic stenosis and coronary ostial stenosis in familial hypercholesterolemia: two-dimensional echocardiographic assessment.

The lesions of the aortic root, which are supravalvular aortic stenosis and coronary ostial stenosis, in familial hypercholesterolemia were studied using two-dimensional echocardiography. The subjects were 25 heterozygotes, six homozygotes and 30 control subjects. The internal diameters of the aortic ring, the sinus of Valsalva and the supravalvular aortic ring were measured. Measurement variation due to body size was avoided by normalizing the latter two values by the diameter of the aortic ring. Four heterozygotes and all homozygotes were judged to have stenosis of the supravalvular aortic ring; none of heterozygotes and four homozygotes had stenosis of the sinus of Valsalva. In three of the four patients with stenosis of both the supravalvular aortic ring and the sinus of Valsalva, a pressure gradient was demonstrated. The degree of supravalvular aortic stenosis correlated with the serum cholesterol level but not with patient age. All homozygotes, even very young ones, had a severe aortic root lesion. In the short-axis view of the aortic root, a lump (raised mass) on the aortic wall indicating atheromatous plaquing was demonstrated in five heterozygotes and all homozygotes. Coronary ostial stenosis was shown in three of the four patients whose plaquing echoes were adjacent to the coronary orifice. We conclude that two-dimensional echocardiography is useful in diagnosing lesions of the aortic root in patients with hypercholesterolemia.

Adolescent↗

Chaotic echo motion in the left ventricular cavity. Visualization of ruptured chordae tendineae of the mitral valve by real-time two-dimensional echocardiography.

The aim of the present study is to perform a detailed analysis of the spot echoes which show chaotic motion of the left ventricular cavity of patients with ruptured chordae tendineae. The subjects were 12 patients with surgically documented ruptured chordae tendineae. They were carefully examined preoperatively by real-time two-dimensional echocardiography with a commercially available wide-angle phased array system (Toshiba SSH-11A). An abnormal moving spot echo was often seen instantaneously in the left ventricle. Its motion was chaotic, and it moved both longitudinally and laterally. Lateral movements were seen in 10 of the 12 subjects and were not found in any of 10 controls. The site of this echo in the left ventricle was identical with the site of the rupture of the mitral chordae confirmed during surgery. Therefore, it was concluded that the spot echo with chaotic motion represents a direct visualization of ruptured chordae. This chaotic motion is considered to be a useful clue in diagnosis. The lateral component (left to right) of the movement is especially important. However, one must carefully examine the left ventricular cavity with moving pictures over a period of many heart beats in order to detect these chaotic movements of spot echoes.

Adolescent↗

[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.

Adolescent↗

Surgical treatment of giant left atrium combined with mitral valvular disease. Plication procedure for reduction of compression to the left ventricle, bronchus, and pulmonary parenchyma.

Giant left atrium associated with mitral valvular disease frequently produce postoperative problems with regard to hemodynamical and respiratory management. A new procedure of para-annular and superior plication combined with the conventional right-side plication with trimming of the left atrial wall was devised to relieve compression induced by the giant left atrium. A total of 40 patients with giant left atrium underwent operation. Ten had the valvular procedure only and 30 had the valvular and plication procedures. The plication procedure resulted in a significant decrease in the incidence of low-output syndrome and respiratory failure postoperatively, as well as a marked decrease in mortality. We conclude that the plication procedure is an effective means of relieving compression in the presence of giant left atrium.

Adult↗

Echocardiographic study of abnormal position and motion of the posterobasal wall of the left ventricle in cases of giant left atrium.

In 35 of 70 patients with rheumatic mitral valve disease, two dimensional echocardiography revealed the posterobasal wall of the left ventricle to be entrapped between the left ventricular and atrial cavities and bent inward. The motion of the bending segment was paradoxical. This abnormality was assumed to be induced by the left atrial dilatation extending inferiorly behind the left ventricle, because the length of the bending segment correlation with the left atrial dimension. There was no correlation between the degree of abnormal bending and left atrial pressure, mitral valve pressure gradient or left ventricular dimension. The systolic excursion of the posterobasal wall of the left ventricle was reduced according to the length of the bending segment. This abnormal feature was also observed in five postmortem heart specimens with an extremely dilated left atrium. The macroscopic and microscopic findings in the myocardium of the bending segment were not different from those of the remaining segment of the left ventricle. Therefore, the asynergic motion of the bending segment is assumed to be caused by the abnormal spatial orientation of the left ventricle and the left atrium. It should be considered that the giant left atrium not only oppresses the surrounding organs but also affects the left ventricle.

Adult↗

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.

Adolescent↗

Idiopathic mitral valve prolapse-analysis by real-time two-dimensional echocardiography.

Mitral valve prolapse is diagnosed in real-time two-dimensional echocardiograms when there are discrepancies in the coaptation zone of the anterior mitral leaflet and the posterior mitral leaflet. Out of the 100 cases of mitral valve prolapse diagnosed in this way, 65 had prolapsed anterior mitral leaflets, 28 prolapsed posterior mitral leaflets and 7 prolapses of both the anterior and posterior mitral leaflets. In addition to the cases with mitral valve prolapse 23 cases of ruptured chordae tendineae of the mitral valve, including 15 cases which had undergone surgery, were investigated. The frequent site of mitral valve prolapse was the posteromedial commissure in the anterior leaflet and the posteromedial and anterolateral commissures in the posterior leaflet. These sites coincide with those where rupture of the chordae tendineae of the mitral valve was apt to occur. An investigation of the relation between age and mitral valve prolapse showed that the number of cases of prolapsed anterior leaflet did not increase with age, but there was an age-related increase in the number of cases of prolapsed posterior leaflets. It was also found that the degree of the prolapse progressed with age. Many of the cases of ruptured chordae tendineae of the mitral valve were in their forties or fifties, and there appeared to be some relation between the progress of the prolapse and age. Mitral regurgitant murmurs were recorded on phonocardiograms, and the severer the degree, the wider the range of the prolapse. Mitral regurgitation was more likely to occur in cases of prolapsed posterior leaflets than in those with prolapsed anterior leaflets, even if the degree and the range of the prolapse were mild.

Adolescent↗

Surgical treatment on mitral valvular disease with giant left atrium-the effect of para-annular plication on left atrium.

In severe mitral valvular disease with a giant left atrium, there occur such abnormal findings as the compression and bending of the basal portion of the posterior wall of the left ventricle accompanied by its paradoxical movement. Following mitral valve replacement in this group of patients, it was found that the strut of the artificial valve is apt to lean against the ventricular septum and the inflow stream of blood was directed toward outflow tract of the left ventricle, appearing to be obstructed by the ventricular septum. Here, we devised a new surgical method, para-annular plication, for patients with a giant left atrium. By this procedure, the compression and bending of the basal portion of the posterior wall of the left ventricle and the paradoxical movement were all relieved. The abnormal angle of the mitral valvular ring was corrected, the strut of the artificial valve was free from contact with the ventricular septum and the inflow stream of blood was directed toward the apex of the ventricle in usual manner. The overall operative result for giant left atrium has been markedly improved by this procedure.

Cardiomegaly↗

[New echocardiographic criterion in the diagnosis of mitral valve prolapse].

Currently, echocardiographic diagnosis of mitral valve prolapse is made when the mitral leaflets protrude into the left atrium crossing the mitral ring. However, there remains the possibility that some mitral valve prolapse, particularly mild one, is overlooked by the currently used criterion. In the present study, new echocardiographic criterion in the diagnosis of mitral valve prolapse is proposed. The criterion includes the systolic dislocation of the mitral leaflets at its coaptation zone. The validity of the new criterion is supported by the following facts. (1) Dislocation of the mitral leaflets at the coaptation zone was never observed in healthy subjects. (2) Real-time two-dimensional echocardiograms from eight cases with a midsystolic click and a late systolic murmur, the characteristic phonocardiographic findings of mitral valve prolapse, invariably demonstrated the dislocation of either the anterior or posterior mitral leaflet at the coaptation zone leading to the diagnosis of mitral valve prolapse. Four of five cases with a midsystolic click and a holosystolic murmur were also diagnosed echocardiographically as mitral valve prolapse based on the proposed criterion. However, two of the former cases and one of the latter cases did not demonstrate the protrusion of the mitral leaflets into the left atrium crossing the mitral ring, indicating inability to diagnose mitral valve prolapse based on the commonly adopted criterion. (3) Based on the extent and degree of dislocation of the coaptation of the mitral leaflets, mitral valve prolapse could be classified into nine grades. It was found that the incidence of mitral regurgitation proved by phonocardiography or angiocardiography is higher as the grade of prolapse becomes greater.

Echocardiography↗

[Visualization of the false tendon in the left ventricle with echocardiography and its clinical significance (author's transl)].

Echocardiographic features of the false tendon in th left ventricle and its clinical significance were reported. The subjects consisted of 132 consecutive patients, in whom the left ventricle was satisfactorily examined from various aspects with two-dimensional echocardiography. In general, the false tendon was detected in the long axis view of the left ventricle from the apical approach. It was detected in 61 of 132 consecutive patients with echocardiography. The incidence did not seem to be related to the kinds of underlying conditions. The false tendon was usually a string, a few millimeters in width, crossing the ventricular cavity from the vicinity of the papillary muscles to the interventricular septum. In a few patients it looked as Y-figure and net like. Sometimes, several sticks of the false tendon were detected. It was observed to be stretched in diastole and relaxed in systole. On the M-mode echocardiogram the false tendon was displayed as a linear echo moving with heart beat. The false tendon revealed near the interventricular septum, exhibited a motion so similar to that of the interventricular septum that it should be carefully differentiated from the echo of the left ventricular surface of the septum. In 2 patients of valvular heart disease, it was observed to be fluttered in diastole. Echocardiography was more useful in detecting the false tendon than left ventriculography.

Aged↗