Biomedical subjects

T Akasaka

Publications and source records attributed to T Akasaka.

At least 217 records · Page 12Linked to original sources

PubMed1989

Continuous aortic regurgitation in severely dysfunctional native hearts after heterotopic cardiac transplantation.

Doppler techniques were used to investigate the frequency and characteristics of aortic regurgitation (AR) in the severely deteriorated native heart after heterotopic cardiac transplantation. Ten patients were studied in whom the native left ventricular fractional shortening was less than 6%. AR was detected by Doppler in 6 patients. The AR was continuous throughout the cardiac cycle in 3 patients, continuous when present (but not occurring with every beat) in 2 patients and present throughout diastole and continued into midsystole in the remaining patient. AR was associated with abnormalities of aortic valve opening (either its complete or intermittent absence) and with poor forward flow and even reversed flow through the native heart. It is postulated that AR in this group mainly occurs as a result of abnormal locking of the aortic valve due to severely impaired left ventricular ejection. Abnormal left ventricular diastolic function and enlargement may also be contributory.

Adult↗

PubMed1989

Temporal resolution of mitral regurgitation in patients with mitral valve prolapse: a phonocardiographic and Doppler echocardiographic study.

To assess the timing and duration of mitral regurgitation in mitral valve prolapse, 20 patients with a mid-systolic click or late systolic murmur, or both (Group 1) and 16 patients with a pansystolic murmur with late systolic accentuation (Group 2) were studied with phonocardiography and echocardiography including various Doppler techniques. The subjects' ages ranged from 15 to 73 years. Mitral valve prolapse with mitral regurgitation was observed in 15 of 20 patients in Group 1 and in all 16 patients in Group 2. M-mode Doppler color echocardiography demonstrated a mitral regurgitant signal throughout systole and isovolumic relaxation in all but 1 of these 31 patients regardless of the pattern of the systolic murmur. The regurgitant signal was recorded after the click in only one patient with mitral valve prolapse in Group 1. Two of the five patients in Group 1 without two-dimensional echocardiographic findings of mitral valve prolapse had the early systolic signal of mitral regurgitation. The timing and duration of the mitral regurgitant signal detected in patients in Group 1 with pulsed or continuous wave Doppler ultrasound varied with the site of the sample volume or beam direction. In the patients in Group 2, however, the signal was demonstrated throughout systole and isovolumic relaxation by both Doppler methods. Compared with M-mode Doppler color echocardiography, therefore, pulsed and continuous wave Doppler methods were less sensitive and thus inadequate to investigate the timing and duration of mitral regurgitation in mitral valve prolapse, especially in patients with a mid-systolic click or a late systolic murmur, or both, who had mild or eccentric mitral regurgitant jets.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1989

Electron microscopic study of the colloid-like substance in solar elastosis.

We have made electron microscopic studies on the elastotic material of solar elastosis which developed in cutis rhomboidalis nuchae taken from 10 males, 50-83 years of age. It was revealed that this material of the cutis rhomboidalis nuchae contained a colloid-like substance consisting of both a fine granular and an amorphous component. The colloid-like substance closely resembled that which is seen in the adult-type colloid milium, and could not be distinguished from it under light microscopy. In view of the morphological similarity at the ultrastructural level between the elastotic material and the colloid-like substance, it was proposed that normal elastic fibers can change into elastotic material and then further degenerate into the colloid-like substance, eventually becoming the typical colloid substance seen in colloid milium.

Aged↗

PubMed1989

Assessment of left-to-right atrial shunting after percutaneous mitral valvuloplasty by transesophageal color Doppler flow-mapping.

To evaluate left-to-right shunts after percutaneous balloon mitral valvuloplasty, we studied 15 consecutive patients by using transesophageal color Doppler flow-imaging system. Transesophageal color Doppler examinations were performed five times in each patient (before valvuloplasty and 1 day, 1 week, 1 month, and 6 months after valvuloplasty). No shunt flow was observed before valvuloplasty. On 1 day after mitral valvuloplasty, transesophageal color Doppler echocardiography demonstrated left-to-right shunts in 13 (87%) of 15 patients. However, a significant oxygen step-up was present in the right heart in only one patient. The mean diameter of the interatrial septal defect detected by transesophageal two-dimensional echocardiography was 1.8 +/- 1.0 mm. The mean velocity of left-to-right shunting flow measured by high-pulse repetition frequency Doppler technique was 0.83 +/- 0.38 m/sec. One week after the procedure, left-to-right shunt flow was detected in 11 (73%) patients. One month after valvuloplasty, left-to-right shunting flow was detected in seven (47%) of 15 patients. There was a significant decrease in the diameter of an interatrial septal defect between 1 day and 1 week (p less than 0.01), between 1 week and 1 month (p less than 0.01), and between 1 month and 6 months (p less than 0.05). Six months after valvuloplasty, left-to-right shunting flow remained in three (20%) patients. By using transthoracic color Doppler echocardiography, we detected left-to-right shunting flow in two patients on 1 day after the procedure.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1989

[Electron microscopic and immunohistological studies of a case of Ehlers-Danlos syndrome type IV].

A 5-year-old male considered clinically to have Ehlers-Danlos syndrome (EDS) type IV with main symptoms of fragility and easy bruisability of the skin was presented. Electron microscopic observations of collagen fibers and immunohistological examination of the localization of the type III collagen in the patient revealed dissimilarities in the size and the irregularities in the shape of collagen filaments, as well as a clear difference in localization of type III collagen when compared with normal skin of same age.

Child, Preschool↗

PubMed1989

[Treated case of aortic valve regurgitation associated with Behçet's disease].

Aortic valve replacement was performed to the incompetence of valve cusps with the Behçet's disease. Artificial valve was fixed from the outside of the aortic wall using teflon strips. Satisfactory results were obtained. There are 18 cases of aortic valve regurgitation accompanied with Behçet's disease including this reported case. Not only the aortic valve but also surrounding aortic walls are involved by the inflammatory lesion in Behçet's disease, so that such fixation technique of the prosthetic valve as demonstrated above might be useful. Since Behçet's disease is systemic, progressive and chronic disease, anti-inflammatory treatment with the adrenal steroids is required prior to and after the operation, and there is no distinct method of treatment for Behçet's disease, strict observation of the patient and systemic controls should be recommended continuously.

Aortic Valve↗

PubMed1989

[Two cases of squamous cell carcinoma arising from erythema ab igne].

This report describes two female patients, 69 and 79 years old, with squamous cell carcinoma (SCC) developing from erythema ab igne (EAI) due to thermal irradiation from a sunken hearth (irori in Japanese) or an underfloor brazier covered with a quilt (kotatsu in Japanese). EAI on the knees and lower thighs showed reticular pigmentation at its periphery and poikiloderma in the center with many keratotic nodules. In both cases, the SCCs were located almost symmetrically on an anterior site 1/3 of the way down both lower thighs. They were surrounded by many keratotic nodules. Histologically, these nodules showed an atypia of the epidermal cells, indicating carcinoma in situ resembling actinic keratosis ro Bowen's disease. It was also strongly suggested that the SCCs in these patients had developed from the keratotic nodules. EAI appeared to have played a pathogenetic role in the cutaneous carcinoma.

Aged↗

PubMed1989

[Transesophageal echocardiographic findings of mitral valve prolapse].

Transesophageal echocardiography (TEE) is a new approach to the investigation of the heart, at a closer range without interference from lung tissue or ribs. In this study, we evaluated 15 patients with mitral valve prolapse by TEE. All patients had a pansystolic murmur and severe mitral regurgitation by left ventriculography. Seven patients underwent cardiac surgery. The presence of ruptured chordae tendineae was confirmed in all these patients at the time of operation. The transesophageal echocardiographic finding of mitral valve prolapse was a circular or coiled cusp or whip-like protrusion of a scallop into the left atrium in systole. TEE disclosed ruptured chordae tendineae in all of the seven patients with ruptured chordae tendineae confirmed by surgery, whereas transthoracic echocardiography disclosed only one. In the remaining patients, TEE disclosed chordal rupture in six. The prolapsed sites by TEE were coincident with those by cardiac surgery in each patient. By three-dimensional construction of the mitral valve using TEE, the direction of mitral regurgitant jet was correctly visualized. In conclusion, TEE is useful in evaluating patients with mitral valve prolapse and is a sensitive method for detecting ruptured chordae tendineae.

Chordae Tendineae↗

PubMed1989

[Silent severe tricuspid regurgitation: a study by Doppler echocardiography].

Sixty-eight patients with severe tricuspid regurgitation proven by right ventriculography were examined using pulsed and continuous wave Doppler echocardiography and color Doppler flow imaging. Among the 68 patients, there was no tricuspid regurgitant murmur in 16 (24%) in whom laminar regurgitant flow signals were demonstrated by pulsed Doppler echocardiography. The area in which laminar flow was detected ranged from 8 to 46 mm2 (mean 19.5 +/- 9.8 mm2). The peak velocities in patients without regurgitant murmurs as measured by continuous wave Doppler echocardiography ranged from 1.1 to 1.9 m/sec (mean: 1.61 +/- 0.21 m/sec). Laminar regurgitant flow signals were obtained in six; and turbulent regurgitant flow signals in 46 of 52 patients with tricuspid regurgitant murmurs, and their peak velocities ranged from 1.7 to 5.1 m/sec (2.80 +/- 0.78 m/sec). The peak velocities of the regurgitant flow signals in patients without tricuspid regurgitant murmurs were significantly lower than those in patients with regurgitant murmurs (p less than 0.01). In six patients with laminar regurgitant flow signals and regurgitant murmurs, the areas of laminar flow signals ranged from 3 to 12 mm2 (mean 7.0 +/- 3.5 mm2) and were smaller than those of patients without regurgitant murmurs (p less than 0.001). A characteristic candle flame pattern of regurgitant flow signals was observed in all patients without murmurs. Thus, the absence of a tricuspid regurgitant murmur results from laminar regurgitant flow signals of low velocity and this is characterized by a candle flame pattern using color Doppler flow imaging.

Adolescent↗

PubMed1989

[Doppler techniques in the detection of valvular regurgitation: their value and limitations].

To evaluate the clinical value of various Doppler techniques in detecting valvular regurgitation, we compared the sensitivity, timing and duration of regurgitation, and the peak velocity of regurgitant signals among conventional pulsed Doppler, color Doppler, continuous wave Doppler and HPRF Doppler echocardiography. 1. Sensitivity of Doppler techniques in detecting mitral regurgitation: Among fifty patients with mitral regurgitation confirmed by left ventriculography, mitral regurgitation was detected in 48 (96%) using color Doppler and pulsed Doppler echocardiography; in 41 (82%) by HPRF Doppler; and in 37 (74%) by continuous wave Doppler echocardiography. In 103 consecutive normal volunteers, mitral regurgitant signals were detected in 46 (45%) by color Doppler, in 39 (38%) by pulsed Doppler, in 16 (16%) by HPRF Doppler, and in 8 (8%) by continuous wave Doppler echocardiography. 2. Timing and duration of regurgitant signals: To assess the timing and duration of regurgitant signals, 43 patients with regurgitant signals of short duration during systole or diastole were studied using M-mode color Doppler echocardiography. Using the latter method, regurgitant signals throughout systole and the isovolumic relaxation period could be demonstrated in all but four patients who had regurgitant signals of short duration during systole, but suggesting mitral or tricuspid regurgitation. In all patients with regurgitant signals of short duration during diastole, aortic or pulmonary regurgitant signals throughout diastole could be demonstrated with M-mode color Doppler echocardiography. Thus, this technique is superior to conventional pulsed Doppler echocardiography for detecting accurate timing and duration of valvular regurgitation. 3. Peak velocity of regurgitant flow: To compare the peak velocity of regurgitant flow by continuous wave Doppler and by HPRF Doppler echocardiography, 20 patients with mitral regurgitation and 22 patients with tricuspid regurgitation were examined using the both methods. In patients with severe mitral regurgitation, the peak velocity detected by HPRF Doppler echocardiography correlated well (r = 0.96) with that detected by continuous wave Doppler echocardiography. However, in patients with mild mitral regurgitation, the peak velocity detected by HPRF Doppler echocardiography was higher than that detected by continuous wave Doppler echocardiography. In patients with severe tricuspid regurgitation, the peak velocity had a close correlation (r = 0.99) with the both techniques. In patients with mild tricuspid regurgitation, the peak velocity was higher by HPRF than by continuous wave Doppler echocardiography. In conclusion, color or pulsed Doppler echocardiography should be used for detecting valvular regurgitation. M-mode color Doppler echocardiography is superior to conventional pulsed Doppler echocardiography for detecting timing and duration of valvular regurgitation.(ABSTRACT TRUNCATED AT 400 WORDS)

Echocardiography, Doppler↗

PubMed1989

[A case of concomitant association of discrete subaortic stenosis in Kelly type I and hypertrophic cardiomyopathy in early stage].

A 1-year-old baby boy with discrete subaortic stenosis in Kelly type I had coexisting echocardiographic evidence for probably indicating the presence of hypertrophic cardiomyopathy in early stage. At surgery, a discrete subaortic "fibrous membrane" was excised: although the thickening of upper ventricular septum was not thought to be so prominent, the prognosis is related to the natural history of hypertrophied muscle despite successful surgical removal of the subaortic diaphragm.

Aortic Stenosis, Subvalvular↗

PubMed1988

Color Doppler evaluation of valvular regurgitation in normal subjects.

To determine prospectively the prevalence of mitral, aortic, tricuspid, and pulmonary regurgitation in normal persons, 211 consecutive, apparently healthy volunteers were examined with a color Doppler flow imaging system. The subjects were divided into five age groups (group 1, 6-9 years old; group 2, 10-19 years old, group 3, 20-29 years old, group 4, 30-39 years old, and group 5, 40-49 years old). The prevalence rate of mitral regurgitation in the normal subjects was 38-45% in each group. The mitral regurgitant jets came from the posteromedial commissure in all but two subjects. No aortic regurgitant flow signals were detected in the normal subjects. Tricuspid regurgitation was detected in 15-77% in each group, and pulmonary regurgitation was detected in 28-88%. Regarding the tricuspid and pulmonic valves, the prevalence rate of regurgitation is age dependent (p less than 0.01) and tends toward the lower rate in groups over the age of 30 years. The tricuspid and pulmonary regurgitant jets came from the center of the coaptation of each valve. The area of the regurgitant jet signals in normal persons was significantly smaller (p less than 0.001) than that obtained from patients with organic valve disease. Our study shows that in a large proportion of normal persons under the age of 50 years color Doppler echocardiography permits recording of regurgitant signals behind all valves except the aortic. In conclusion, one should be aware of the existence and characteristics of regurgitation in normal persons when evaluating valvular regurgitation by Doppler techniques.

Adolescent↗

PubMed1988

Problems in the management of elderly patients with valvular heart disease.

One hundred and nine patients over the age of 65 years with valvular heart disease have been reviewed. Of these, 57 patients were treated medically (medical group) and the remaining 52 patients underwent valve surgery (surgical group). Of the 57 patients who were treated medically, 46 (81%) were in NYHA Functional Class I or II, 7 were in Class III, and 4 were in Class IV. Among these, there were 8 deaths. The 5 year survival rate of the medical group, calculated by the actuarial method, was 90 +/- 5%. Eight patients had a nonfatal cerebrovascular accident. Of the 52 elderly patients who underwent valve surgery, 20 were in NYHA Functional Class II, 21 were in Class III, and 11 were in Class IV. Of these, there were 5 operative deaths (9.6%). Four patients died of postoperative low cardiac output syndrome and renal failure. One died of intraoperative aortic dissection. Of the 470 patients under the age of 65 years, there were 15 operative deaths (3.2%). Forty-one of the 47 hospital survivors have improved their cardiac functional classification, while 6 patients have remained in the same class as preoperatively. The average NYHA Class prior to operation was 2.7 improved to Class 1.3 after operation. The 3 year survival rate of the surgical group, calculated by the actuarial method, was 81 +/- 6%. Thus, the prognosis of asymptomatic elderly patients is good. Although operative mortality for the symptomatic elderly patients is relatively high, valve surgery can be performed with a satisfactory prognostic outlook.

Actuarial Analysis↗

PubMed1988

[The phase IV studies with Estracyt in prostatic cancer].

Both anticancer and adverse reactions of Estracyt were investigated by oral administration to 200 patients with prostatic cancer. Two capsules of Estracyt were given twice a day and the administration was principally continued for more than six months. The 200 patients consisted of 68 and 132 patients who were previously untreated and treated, respectively. Thirty seven cases had been treated only with Estracyt and 132 cases also received other treatments. Seventy-five cases were of primary therapy, 71 cases were of maintenance therapy, and 27 cases were of the re-activated stage therapy and 27 cases were of other categories. In conclusion, among the 190 cases for which the due judgement of the effect was possible, Estracyt was markedly effective in 40 cases (21.1%), effective in 43 cases (22.6%), slightly effective in 38 cases (20.0%) and ineffective in 69 cases (36.3%). Adverse reactions were observed in 67 cases (33.5%), among which the administration was discontinued in 18 cases.

Administration, Oral↗

PubMed1988

[Late complications of valve replacement: the benefits of non-invasive assessment].

Non-invasive techniques were assessed for their capabilities of detecting prosthetic valve malfunctions in 70 consecutive patients with angiographically-documented or surgically-proven prosthetic valve dysfunction. Their 74 dysfunctioning valves were studied using phonocardiography, M-mode and two-dimensional echocardiography and Doppler methods, including pulsed and continuous wave (CW) Doppler echocardiography and two-dimensional Doppler color flow mapping (2DD). These results were compared among the examinations, and also compared between 43 patients with 44 dysfunctioning mechanical valves and 27 patients with 30 dysfunctioning bioprosthetic valves. Symptoms related to valve malfunction were recognized in all patients with prosthetic valve endocarditis and in all patients but one with stenotic condition. In patients with valvular regurgitation, however, symptoms were observed in only six of the 21 patients with mechanical prostheses and in 12 of the 25 patients with bioprosthetic valves (p less than 0.01). Among 43 patients with 44 mechanical valve dysfunctions, the sensitivities of phonocardiography, M-mode and two-dimensional echocardiography and Doppler techniques were 85, 65 and 86 percent, respectively, in 20 patients with stenosis; 100, 57 and 80 percent in seven patients with transvalvular regurgitation; and 100, 50 and 100 percent in 14 patients with paravalvular regurgitation. Similarly, among 27 patients with bioprosthetic valve dysfunctions, the sensitivities of phonocardiography, M-mode and two-dimensional echocardiography and Doppler methods were 67, 100 and 100 percent, respectively, in three patients with stenotic condition; 85, 65 and 100 percent in 20 patients with transvalvular regurgitation; and 60, 40 and 100 percent in five patients with paravalvular regurgitation. Furthermore, 26 of the 27 patients with malfunctioning mechanical valves and 20 of the 24 patients with malfunctioning bioprostheses had abnormal findings using more than two techniques. In addition, each patient had at least one abnormal finding. In conclusion, malfunctioning mechanical or bioprosthetic prostheses could be detected using non-invasive techniques. The combined use of phonocardiography, M-mode and two-dimensional echocardiography and Doppler techniques is most helpful in detecting malfunctioning prostheses.

Adult↗

PubMed1988

[Time analysis of mitral regurgitation in patients with mitral valve prolapse: a study by phonocardiography and Doppler techniques].

To assess the timing and duration of mitral regurgitation (MR) in patients with mitral valve prolapse (MVP), 20 subjects with mid-systolic click(s) and/or a late systolic murmur were studied using phonocardiography, two-dimensional echocardiography (2DE) and Doppler techniques including pulsed Doppler (PD), high pulse repetition frequency Doppler (HPRF), continuous wave Doppler (CW) and M-mode color Doppler (MD) methods and two-dimensional Doppler color flow mapping (2DD). The results were compared with those of 16 patients with a pansystolic murmur having late systolic accentuation. MVP with MR was observed in 15 of the 20 patients with mid-systolic clicks and/or a late systolic murmur and in all of the 16 patients with a pansystolic murmur. Using MD, MR signals were seen throughout systole and isovolumic relaxation period in all but one of these patients, and they were not related to the patterns of the systolic murmur. In only one, an MR signal was recorded just after the click. Five patients with a mid-systolic click lacked the findings of MVP, but two of them had MR signal only in early systole. Using PD and HPRF techniques, the timing and duration of MR signals in patients with mid-systolic clicks and/or a late systolic murmur were varied by changing the sites of the sample volume. Similarly, the timing and duration of MR signals in these patients were dependent on the ultrasonic beam direction by the CW method. In most patients with a pansystolic murmur having late systolic accentuation, however, MR signals throughout systole and the isovolumic relaxation period were demonstrated by each Doppler method. Therefore, PD, HPRF, and CW were not so efficiently sensitive or adequate techniques for investigating the timing and duration of MR, especially in patients with mid-systolic clicks and/or a late systolic murmur, who had mild or eccentric MR jets. In conclusion, 1) MR in MVP involves the entire systole and isovolumic relaxation period, 2) PD, HPRF and CW methods are not adequate for detecting mild or eccentric MR jets in patients with mid-systolic clicks and/or a late systolic murmur, and 3) MD is useful for the time analysis of MR in these patients.

Adolescent↗

PubMed1988

[Ventricular free wall rupture following acute myocardial infarction: a two-dimensional echocardiographic assessment].

To assess the usefulness of two-dimensional echocardiography (2DE) in diagnosing ventricular free wall rupture following acute myocardial infarction, we studied the 2DE findings and the clinical pictures of seven consecutive patients with ventricular free wall rupture confirmed at the time of surgery or autopsy. Three patients had acute rupture; four, subacute rupture. All patients apparently had circulatory collapse despite continuing electrical activity at the onset of cardiac rupture. Four patients with subacute rupture recovered. In all patients, mild pericardial effusion was imaged by 2DE; however, this was not characteristic for cardiac rupture. In the patients with acute rupture, active left ventricular contractions were not observed after each QRS complex of the electrocardiogram. However, weak mitral valve motion was recorded at the time of cardiopulmonary resuscitation. The interesting and constant finding in acute rupture was the right ventricular collapse observed throughout the cardiac cycle. Diastolic right ventricular collapse was consistently observed in patients with subacute rupture, immediately after recovery from cardiogenic shock. Subacute cardiac rupture is a potentially curable lesion, and the clinical features and quick 2DE confirmation of cardiac tamponade allowed immediate surgery which saved two of the four patients.

Adult↗

PubMed1988

[Color Doppler evaluation of a specific left ventricular flow pattern in a case of left ventricular pseudoaneurysm].

This report describes a case of left ventricular pseudoaneurysm examined by phonocardiography, two-dimensional echocardiography, Doppler color flow mapping, continuous wave and conventional pulsed Doppler echocardiography. The patient had early systolic and early diastolic murmurs. The pseudoaneurysm sac and the site of left ventricular rupture were identified by two-dimensional echocardiography. The flow between the left ventricle and the pseudoaneurysm were imaged by Doppler color flow mapping. Two jets from the left ventricle were directed toward the aneurysm during systole, and from the aneurysm toward the left ventricle in early diastole. Continuous wave Doppler and high pulse repetition frequency Doppler echocardiography demonstrated the maximum flow velocity in systole to be 3 m/sec and in early diastole, 1.7 m/sec. Those flow patterns between the left ventricle and the pseudoaneurysm could have been closely related to the murmur. Doppler echocardiography thus proved useful for detecting specific flow patterns related to a left ventricular pseudoaneurysm.

Aged↗