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Biomedical subjects

S Makihata

Publications and source records attributed to S Makihata.

14 recordsLinked to original sources
PubMed1987

[Blood flow patterns in the left ventricle in patients with myocardial infarction and ventricular aneurysm: evaluation using real-time two-dimensional Doppler echocardiography].

To evaluate how the intraventricular blood flow is affected by the size of a left ventricular aneurysm and ventricular dysfunction, systolic left ventricular blood flow patterns were evaluated using two-dimensional Doppler flow images (real-time 2-D Doppler echo). The subjects consisted of 10 normal controls, 35 patients with anteroseptal infarction, two patients with inferior infarction and five patients with anteroseptal-inferior infarctions. The systolic period was divided into three subsets; early, mid- and end-systole. Forty-two patients with myocardial infarction were classified into three groups according to the left ventricular inflow patterns on real-time 2-D Doppler echo using the apical left ventricular long-axis approach; i.e., inflow signals confined to early systole (Group I), visualized up to mid-systole (Group II) and end-systole (Group III). Left ventricular end-diastolic dimension (LVDd), left ventricular end-systolic dimension (LVDs), and % non-contractile circumference (delta L) were calculated by the same echocardiographic approach. Ejection fraction (EF) was calculated by left ventricular cineangiography using the Simpson's method. The left ventricular inflow Doppler signals in the normal controls and Group I turned in the apex and then directed toward the left ventricular outflow tract during late diastole and early systole. Significant differences in EF were observed among the three groups. EF in Group I, II and III was 53 +/- 9%, 41 +/- 8% and 29 +/- 7%, respectively. However, LVDd, LVDs and delta L had the largest values in Group III and the smallest values in Group I. LVDd, LVDs and delta L were smallest in Group I and largest in Group III. In the normal controls, the left ventricular inflow signals proceeded to the apex and directed toward the left ventricular outflow tract in the early systolic period. Various changes in the inflow pattern were observed in patients with myocardial infarction and severe wall motion abnormalities, including delayed timing in proceeding from the apex to the left ventricular outflow tract, stagnant blood at the apex and further inflow of blood toward the apex even during end-systole. The patients with sustained inflow during late systole had hypofunction of the left ventricle as demonstrated by smaller EF and larger LVDd, LVDs, and delta L. In conclusion, the observation of intracardiac blood flows by real-time 2-D Doppler echo is of help in evaluating the severity of myocardial infarction.

Adult↗
PubMed1985

[Two-dimensional echo-Doppler technic for evaluating dissecting aneurysms using the paravertebral approach].

Cross-sectional echocardiography facilitates recognizing dissecting aortic aneurysms, but the diagnosis of abnormalities of the descending aorta in the retrocardiac portion is difficult. We prospectively designed to assess the usefulness of a new echocardiographic technique in defining the retrocardiac descending thoracic aorta in its long and short axes. Two patients with dissecting aneurysms involving the retrocardiac descending aorta were studied in the 90 degrees right lateral position using a Toshiba SSH-11A or SSH-40A cross-sectional echocardiographic apparatus. The transducer was positioned in the third or fourth intercostal space closely to the left of the thoracic vertebrae, and the ultrasonic beam was directed toward the retrocardiac descending aorta from the patient's back. The descending thoracic aorta was identified in its long axis as a straight tubular structure with parallel walls. The transducer was then rotated approximately 90 degrees, to visualize the descending aorta in its short axis as a circular structure. This "paravertebral approach" has not previously been reported. In both patients, the retrocardiac descending thoracic aorta was clearly visualized in its long and short axes, and the oscillating intimal flap was visualized within the descending aorta in the paravertebral approach. Pulsed Doppler echocardiography (PDE) using the long-axis paravertebral approach identified the flow in the false and true lumens of the descending thoracic aorta. Flow patterns including the peak flow velocity and the velocity profile obviously varied between the true and false lumens. The peak flow velocities in the former were extremely high compared to those in the latter. The former exhibited laminar profiles, but the latter showed some spectral broadening. By the same approach, the entrance tear was explored and the jet flow through the tear was detected in Case 1 by PDE, which had high flow velocity with wide spectral broadening and aliasing in systole and also had relatively low flow velocity with some spectral broadening in diastole. To our knowledge, there has been no previous report of detecting flow at the entrance tear by PDE. These cross-sectional echocardiographic studies suggest that the paravertebral approach may prove helpful in initially evaluating patients with symptoms or signs suggestive of acute dissecting aneurysms. However, comprehensive studies are necessary to define the sensitivity and specificity of these echocardiographic techniques in recognizing all types of dissecting aneurysms.

Aged↗
PubMed1985

[Two-dimensional echocardiography in ventricular septal rupture after acute myocardial infarction].

We studied the echocardiographic findings of 11 patients with proven ventricular septal defect following acute myocardial infarction. There were seven men and four women whose ages ranged from 48 to 77 years, with an average of 66 years. Nine patients had acute anterior and two acute inferior myocardial infarctions. Two-dimensional echocardiography (2DE) was performed for eight patients and M-mode echocardiography for all 11 patients. In all eight patients with apical four-chamber view, in whom four had additional apical short-axis view, the septal defect was directly visualized, but it was not detected by M-mode echocardiography. The defect was visualized in the apical region of the septum in all eight patients by the apical four-chamber view. The anteroapical region of the septum was the site in three with anterior infarction and the inferoapical region in one with inferior infarction by the apical short-axis view. In five of the eight patients who underwent 2DE, surgical or autopsy confirmation of the defects was obtained, with a complete agreement with the echocardiographic findings. In two patients with echocardiographic findings of septal defects, the perforations were confirmed at surgery. Two cases with aneurysmal bulges of thin septum into the right ventricle had the thin necrotic muscle in the anteroapical regions. One patient with a cystic bulge into the septum showed an irregular tear in the inferoapical region of the septum at surgery. In eight patients, the left ventricular wall motion was assessed by 2DE. Six patients revealed hyperkinetic motion in the non-infarcted areas of the basal septum or posterior wall, and these cases had good prognosis. We concluded that 2DE is a sensitive, prompt and safe technique for diagnosing and observing the risk of complicating septal defects in acute myocardial infarction. In this respect, both the apical four-chamber and short-axis views should be utilized for the topographic diagnosis of the defect.

Aged↗
PubMed1984

[Pulsed Doppler echocardiographic evaluation of so-called "moyamoya" echoes in left ventricular aneurysms].

So-called "moyamoya" echoes identified by two-dimensional echocardiography (2 DE) in two cases with ventricular aneurysm were studied by pulsed Doppler echocardiography. The results were as follows: The flow velocity patterns in the left ventricle obtained by pulsed Doppler method were consistent with those observed by the real time 2DE method; the moyamoya echoes moved in a slow, circular fashion, and only a flow with slow velocity toward the transducer was recorded in the posterior area, whereas only a flow with slow velocity away from the transducer was recorded along the interventricular septum during cardiac cycle. The ejection flow velocity at the left ventricular outflow tract was markedly diminished. The flow velocity of the moyamoya echoes was extremely decreased and ranged between 50 and 135 mm/sec. The velocity measurements by M-mode and pulsed Doppler echocardiography gave almost the same values. Thus, the results of the present report suggest that the moyamoya echoes behave like moving blood cells, and that the source of these echoes is the sludging in the stasis of blood.

Aged↗
PubMed1984

[Echocardiographic study of right ventricular performance by acute and chronic pressure overloadings].

Echocardiographic analysis of right ventricular ejection time (RVET), pre-ejection time (RVPEP), RVPEP/ET and isovolumic relaxation time (RVIRT) was performed in patients with acute or chronic right ventricular pressure overloading. Fifty-five patients undergoing right ventricular cardiac catheterization, were categorized into seven groups; 11 patients with atrial septal defect (ASD) without pulmonary hypertension (PH) (group 1), 12 with ASD with PH (group 2), six with mitral stenosis (MS) without PH (group 3), nine with MS with PH (group 4), seven with primary pulmonary hypertension (PPH) (group 5), seven with acute pulmonary embolism (PE) (group 6), and three patients with convalescence of PE (group 7). Corrected RVIRT (RVIRTc) and RVET (RVETc) were calculated by regression analysis correlating with heart rate in normal subjects. RVIRTc, RVETc, RVPEP and RVPEP/ET in seven groups were significantly correlated with systolic pulmonary artery pressure (SPAP) (r = 0.62, p less than 0.001; r = -0.41, p less than 0.01; r = 0.61, p less than 0.001; r = 0.65, p less than 0.001, respectively), but RVDd did not correlate with SPAP (r = 0.370, p less than 0.05). Comparing acute right ventricular pressure overloading group (group 6) with each of chronic right ventricular pressure overloading groups (groups 2, 4, 5, and 7), RVIRTc and RVDd were significantly increased in the former than the latter, but RVETc, RVPEP and RVPEP/ET were not significantly different in both groups. There was a significant correlation between RVIRTc and RVPEP/ET in chronic pressure overloading, but not in acute pressure overloading. We concluded that early diastolic RV relaxation and systolic performance were both impaired by increased afterload in chronic pressure overloading. In acute pressure overloading, however, early diastolic RV relaxation was more significantly impaired possibly because of acute changes of muscle architectures due to acute right ventricular expansion and anoxia.

Blood Pressure↗
PubMed1983

[M-mode and two-dimensional echocardiography in the evaluation of right atrial masses].

Five cases of miscellaneous right atrial mass were described to illustrate the very valuable diagnostic contribution of two-dimensional echocardiography (2DE). Two patients had a large myxoma in the right atrium, and other two had an extension of hepatoma into the right atrium through the inferior vena cava. The fifth patient with a past history of myocardial infarction had a floating right atrial thrombus. The myxoma in the right atrium appeared as a mottled, ovoid, and sharply demarcated mobile mass attached to the interatrial septum. The diagnosis of these two patients was confirmed at operation. The right atrial myxoma in the first case weighed 310 g and filled almost the entire right atrium and right ventricle. To our knowledge, this was the largest myxoma among previously reported cases. The hepatoma extended into the right atrium resembled myxoma, but was obscurely demarcated. The 2DE was useful to localize a large immobile mass extending into the right atrium. All these right atrial tumors were adequately demonstrated in the right lateral decubitus position with the transducer over the right parasternal position. In the fifth case, bedside real-time 2DE was performed after the attack of pulmonary thromboembolism, and an irregular echogenic mass was seen to float freely, suggesting a thrombus. Following the immediate anticoagulant therapy with heparin, the thrombus echo was no longer visible by 2DE. It was concluded that 2DE should be extensively applied to diagnose right atrial tumors or thrombi.

Adult↗
PubMed1982

Echocardiographic abnormalities of tricuspid valve motion in pulmonary embolism.

Echocardiographic findings in five patients with pulmonary embolism were studied. Tricuspid echocardiograms showed abnormalities in valve motion, that is a monophasic triangular wave during diastole in all the patients as well as an increased dimension of the right ventricle. An "a' dip of the pulmonary valve echocardiogram was also recognised in all five. Later tricuspid echocardiograms regained the normal M-shaped configuration. The monophasic triangular pattern of the tricuspid valve during diastole may be related to the shorter duration of tricuspid valve opening compared with that of the mitral valve. Tachycardia cannot explain this difference between tricuspid and mitral valve motion, which seems to be caused by a prolonged isovolumic relaxation time of the right ventricle resulting in a delayed opening of the tricuspid valve. These results were obtained by comparing these data with those of control subjects and patients with chronic right ventricular overloading resulting from atrial septal defect.

Adult↗
PubMed1982

[Echocardiographic triangular pattern of the mitral valve during acute pressure overload of the left ventricle: an experimental study].

The changes of mitral valve echo and hemodynamic data [isovolumic relaxation time (IRT)/square root R-R, time constant T, peak positive dP/dt/P, left ventricular enddiastolic pressure (LVEDP) and left ventricular systolic pressure (LVSP] during acute pressure overload produced by aortic root obstruction were analyzed in 13 mongrel dogs under sodium pentbarbital anesthesia (25 mg/kg). IRT/square root R-R, time constant T, positive dP/dt and LVSP were expressed as percent changes to the value (=100%) of pre-pressure overload, LVEDP was expressed by an absolute value as mmHg. In 7 of 13 dogs, an abnormal diastolic monophasic triangular pattern of the mitral valve was observed during acute pressure overload of the left ventricle, and values of five hemodynamic data were compared between cases with or without the triangular pattern. The values of IRT/square root R-R, time constant T, positive dP/dt/P, LVSP amd LVEDP in cases with the triangular pattern became from 200 to 500% (275 +/- 100%), from 175 to 267% (220 +/- 50%), from 55 to 112% (81 +/- 21%), from 129 to 200% (59 +/- 21%) and from 7 to 33 mmHg (16 +/- 9 mmHg), respectively. The values of IRT/square root R-R, time constant T, positive dP/dt/P, LVSP and LVEDP in cases with the non-triangular pattern became from 116 to 155% (133 +/- 17%), from 116 to 154% (136 +/- 16%), from 111 to 186% (62 +/- 34%) and from 9 to 20 mmHg (9 +/- 6 mmHg), respectively. Thus, the values of IRT/square root R-R and time constant T were significantly different between the two groups. The possible explanation for the triangular pattern of the mitral valve seems to be due to impaired active relaxation system of the left ventricle resulting in a markedly delayed opening of the mitral valve. We conclude that early diastolic isovolumic relaxation of the left ventricle is impaired by acute pressure overload, and the echocardiographic diastolic monophasic triangular pattern of the mitral valve reflects this impairment.

Animals↗
PubMed1982

[M-mode and two-dimensional echocardiographic features of porcine xenograft valve dysfunction].

Clinical survey was made on the porcine xenograft valve replacements in 76 patients who underwent the replacement for the past five years at Hyogo College of Medicine Hospital. The follow-up period was from 3 to 84 months after implantation. Seventy-one patients had mitral valve replacements, 1 aortic, 2 mitral and tricuspid and 2 tricuspid. Seven patients were diagnosed as porcine valve dysfunction echocardiographically, and in four of these the dysfunction (two with bacterial endocarditis, one with perivalvular leak and one with ruptured porcine aortic valve) was confirmed at operation, and the echocardiographic features were correlated with surgical findings. M-mode and two-dimensional echocardiograms of one patient with fungal endocarditis demonstrated vegetations on the mitral and tricuspid valves. In another patient with endocarditis, the echocardiographic finding of valve thickening associated with the flail and torn cusp was observed. The two-dimensional echocardiographic study was particularly useful in detecting the dislocation of the stent echo in one patient with paravalvular regurgitation. In one patient with the ruptured and flail porcine aortic valve, the two-dimensional echocardiogram was characterized by rapid diastolic motion of the involved leaflet into the left ventricular outflow tract beyond the line of valve closure. Three patients were not confirmed at operation. In one patient, the two-dimensional echocardiogram demonstrated a systolic prolapse of the porcine mitral valve. In another two patients the M-mode echocardiographic finding included a coarse fluttering of the porcine mitral cusp in diastole. The major M-mode features of prosthetic regurgitation were fuzzy echoes with fluttering of the cusp in systole or diastole or both. In one patient with fluttering, the two-dimensional echocardiogram also demonstrated the thickening of the cusp. But in another patient with fluttering, the two-dimensional echocardiogram revealed no abnormality, and prosthetic regurgitation was not confirmed at cardiac catheterization. It was postulated that this patient had a false positive echocardiogram. Two-dimensional echocardiography complemented the M-mode echocardiographic findings and both techniques were very useful in identifying porcine valve dysfunction. Moreover, we considered that the comparison of the echocardiographic features in the course of individual case was very important in detecting porcine valve dysfunction.

Adult↗
PubMed1982

[Echocardiograms of a monophasic triangular wave of the tricuspid valve].

The echocardiographic and clinical study was performed in six patients (three acute pulmonary embolism, one for each hypertensive cardiomyopathy, ischemic heart disease and primary pulmonary hypertension) who had a diastolic monophasic triangular pattern of the tricuspid valve echogram. Left-sided and right-sided IRT / square root R-R, ICT / square root R-R, PEP, Q-Mc and Q-Tc, and PEP / ET (IRT; isovolumic relaxation time, ICT; isovolumic contraction time, PEP; preejection time, Q-Mc or Q-Tc; interval of the Q wave of the ECG to the closing point of the mitral or tricuspid valve, and ET; ejection time) were measured from echocardiograms, and the comparisons of these parameters were made between two kinds of echogram with or without triangular pattern of the tricuspid valve. There were no significant differences in the left-sided parameters between the two kinds of echocardiograms. The mitral valve echogram showed a persistent M-shaped pattern irrespective of the pattern of the tricuspid valve. Right-sided IRT / square root R-R and ICT / square root R-R were significantly prolonged and Q-Tc was significantly shortened in the echogram with a triangular pattern of the tricuspid valve. Right ventricular (RV) catheterization was performed using a Swan-Ganz catheter in four patients with the triangular pattern of the tricuspid valve echogram. The mean pulmonary artery pressure ranged from 24 to 96 mmHg (40 mmHg on an average) and RV end-diastolic pressure from 8 to 17 mmHg (12 mmHg on An average). The possible explanation for the production of the triangular tricuspid valve echogram was an impaired early diastolic relaxation and increased stiffness of the RV due to the acute pressure overloading, resulting in a delayed opening and an early closing of the tricuspid valve. We conclude that a diastolic monophasic triangular pattern of the tricuspid valve echogram is a reflection of an impaired early diastolic relaxation and an increased end-diastolic stiffness of the RV.

Adult↗
PubMed1982

[Echocardiography in superacute phase of myocardial infarction: an experimental study].

The significance and usefulness of two-dimensional echocardiography (2DE) in the evaluation of superacute phase of myocardial infarction were studied in 13 dogs with coronary occlusion, and 2DE findings were compared with the hemodynamic indices. Myocardial infarction was produced by the occlusion of anterior descending branch of the left coronary artery in 13 anesthetized adult mongrel dogs. In 6 dogs, the end-diastolic area and percent fractional shortening (%FS) in each short-axis view of the left ventricle at the level of the mitral valve, chordae tendineae, papillary muscles, low papillary muscles and apex were measured during 60 minutes, and end-diastolic wall thickness of infarct area situated in the transitional zone between the septum and the anterior wall were compared with that of non-infarct area immediately and subsequent 60 minutes after occlusion. Positive dP/dt/P, time constant T and cardiac output were measured simultaneously with an echocardiographic study. Severe enlargement and expansion of the left ventricular cavity (ballooning) and a decrease of %FS and thinning of the left ventricular wall perfused by the occluded artery occurred immediately after occlusion and persisted during subsequent 60 minutes. Time constant T was significantly prolonged, while positive dP/dt/P and cardiac output were decreased immediately and continued up to 60 minutes after occlusion. 2DE findings corresponded well with the changes of cardiac function and hemodynamics determined simultaneously. We concluded that the detection of the left ventricular ballooning is important in the diagnosis of superacute phase of myocardial infarction in dogs.

Acute Disease↗
PubMed1981

[Echocardiographic triangular patterns of the mitral valve in acute myocardial infarction: a clinical and experimental study (author's transl)].

Echocardiographic study was performed on the mitral valve echogram in cases with clinical as well as experimental acute myocardial infarction (AMI). The echocardiograms were recorded in 88 patients with AMI within 7 days from the onset. In 8 patients (9%), and abnormal monophasic triangular diastolic pattern of the mitral valve was observed. Among them, 6 were examined within 12 hours after the onset and the remainder 2 within 24 hours. In all 8, markedly prolonged isovolumic relaxation time (IRT) was present. Mitral valve motion, IRT and peak negative dp/dt of the left ventricle were examined in 5 mongrel dogs following obstruction of the main left coronary artery, one of which was followed up for next 24 hours. Following coronary occlusion, the IRT progressively prolonged from the control value of 20 msec to 130 msec (15 min), 130 msec (30 min), 140 msec (1 hr), 150 msec (6 hr) and 150 msec (24 hr), respectively. The respective values of peak negative dp/dt were 2,000, 800, 840, 840, and 620 mmHg/sec. The possible explanation for these changes was the impaired active relaxation of the left ventricle, resulting in a delayed opening (or at least the lack of usual diastolic opening) of the mitral value, which gave an abortive E-point or a markedly delayed D point. We conclude that the diastolic monophasic triangular pattern of the mitral valve echogram in a reflection of the prolonged left ventricular isovolumic relaxation, and an index of impaired left ventricular diastolic relaxation.

Aged↗