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Biomedical subjects

S Minagoe

Publications and source records attributed to S Minagoe.

At least 37 records · Page 2Linked to original sources
PubMed1989

[Continuous wave Doppler echocardiographic evaluations of the severity of mitral regurgitation].

To ascertain the usefulness of continuous wave Doppler echocardiography in evaluating the severity of mitral regurgitation (MR), 29 patients with MR and 10 normal subjects were examined. The patients were categorized in three groups according to the angiographic evidence of severity of MR. To analyze the flow velocity patterns of MR, the time to peak velocity index (time from onset of MR signal to peak flow velocity/duration of MR signal), the A/B ratio (the ratio of the first and second half of the systolic MR signal area), systolic peak velocity, and diastolic peak velocity were measured using continuous wave Doppler echocardiograms. The velocity patterns of MR differed significantly among the three groups. With severer MR, the flow velocity pattern showed an earlier appearance of the peak in systole, a steeper decrease in systole and a greater increase in early diastole. The time to peak velocity index was 55 +/- 7% (mean +/- SD) in mild MR, 42 +/- 6% in moderate MR and 35 +/- 5% in severe MR. This index shortened significantly in accord with the severity of MR (mild vs moderate MR: p less than 0.001, moderate vs severe MR: p less than 0.05). The A/B ratio was 1.06 +/- 0.12 in mild MR, 1.23 +/- 0.10 in moderate MR and 1.41 +/- 0.07 in severe MR. This ratio increased significantly with the severity of MR (mild vs moderate MR: p less than 0.01, moderate vs severe MR: p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Detection of acute myocarditis using nuclear magnetic resonance imaging.

The clinical features, echocardiographic characteristics, and electrocardiographic findings in two patients with acute myocarditis are presented. The first patient had rheumatic myocarditis and the other had probable viral myocarditis. Both patients had regional wall motion abnormalities on the echocardiogram, and the nuclear magnetic resonance image for each patient showed myocardial edema in the area of the wall motion abnormality. These changes disappeared with resolution of the acute disease process. These preliminary data indicate that nuclear magnetic resonance imaging may show myocardial edema in acute myocarditis.

Acute Disease↗
PubMed1987

[Diastolic pulmonary forward flow associated with pulmonary regurgitation demonstrated by Doppler echocardiography].

To demonstrate diastolic pulmonary forward flow, pulsed and continuous wave Doppler echocardiograms were recorded in four patients with postoperative residual pulmonary stenosis and regurgitation (Group I). To clarify the mechanism, we further examined 24 patients with pulmonary regurgitation without diastolic pulmonary forward flow, including three patients with surgical correction of tetralogy of Fallot (Group IIa) and 21 patients with functional pulmonary regurgitation (Group IIb), and compared the peak velocity and pressure half time of pulmonary regurgitation among the three groups. Diastolic pulmonary forward flow was characterized as a flow signal which began after the abrupt cessation of pulmonary regurgitation and continued until the beginning of ejection flow. The onset of the flow coincided with that of premature opening of the pulmonary valve, and was following atrial contraction in one, before atrial contraction in two, and mid-diastolic in one. The velocity of diastolic pulmonary forward flow was increased during inspiration and its maximum velocity was 1.3 m/sec. Simultaneous recording of pressures and continuous wave Doppler echo performed in two patients in Group I showed the equalization of right ventricular and pulmonary artery pressures during the flow. There was no significant difference in the peak velocity of pulmonary regurgitation among the three groups of patients. The mean pressure half time was significantly shortened in patients in Group I (90 +/- 11 msec) compared with those in patients in Group IIa (143 +/- 40 msec, p less than 0.05) and Group IIb (310 +/- 71 msec, p less than 0.001). In conclusion, a diastolic pulmonary forward flow seems to be produced by the rapid equalization of right ventricular and pulmonary artery pressures due to severe pulmonary regurgitation in the face of decreased right ventricular compliance.

Adult↗
PubMed1987

[Incidence of tricuspid regurgitation in normal subjects according to a new Doppler echographic criterion].

To develop a Doppler echocardiographic criterion for tricuspid regurgitation (TR) and to determine the incidence of TR in normal subjects, we examined 357 apparently normal subjects ranging in age from five to 95 years using pulsed and continuous wave Doppler echocardiography. A Doppler transducer was placed over the right ventricular apex, with the Doppler beam directed parallel with TR flow. TR was judged to be present when a holosystolic abnormal flow pattern with the peak velocity greater than 1.5 m/sec was recorded at the tricuspid valve orifice. This was based on the theory that in TR systolic pressure gradient across the tricuspid valve should be 10 mmHg or greater in normal subjects. TR was detected in 87 (24%) of 357 subjects and the mean peak velocity of the TR was 2.1 +/- 0.2 m/sec (mean +/- SD). It was more frequent in women (28%) than in men (19%) and differed significantly among the young, middle and old age groups. It was 79% in the first decade, 30% in the second, 10% in the third, 21% in the fourth, 5% in the fifth, 19% in the sixth, 14% in the seventh, 23% in the eight, 37% in the ninth and 40% in the tenth. The minimum dimension of the tricuspid annulus was significantly enlarged (p less than 0.001) in subjects with TR (2.2 +/- 0.3 cm/m2) compared to that of subjects without TR (1.8 +/- 0.3 cm/m2).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

Two-dimensional echocardiographic demonstration of restoration of normal wall motion after acute myocardial infarction.

Left ventricular wall motion was assessed by 2-dimensional (2-D) echocardiography in 17 patients admitted with a first transmural acute myocardial infarction (AMI). The left ventricular myocardium was divided into 17 segments and wall motion was scored from 1 (dyskinesia) to 6 (hyperkinesia) in each segment. Reproducibility of the wall motion scoring system when assessed separately by 2 observers was 89% and when assessed by the same observer at different times, 91%. Seven patients had anterior and 10 inferior wall AMI on the electrocardiogram. Abnormal wall motion was present in 7.3 +/- 2.8 segments (mean +/- standard deviation) on the initial 2-D echocardiogram. On follow-up echocardiograms wall motion was unchanged in 7 patients. In 5 wall motion improved by at least 2 in 2 or more contiguous segments. In 5 other patients wall motion returned to normal in all segments that had shown an abnormality on the initial echocardiogram. These 5 patients (group A), compared with the 12 patients in whom wall motion did not return to normal in all segments (group B), showed fewer involved segments (5.4 +/- 1.7 vs 8 +/- 2.8) and a higher total wall motion score (76 +/- 4 vs 63 +/- 7) (p less than 0.05) on the initial echocardiogram. Duration from the time of the AMI to return of normal wall motion in group A varied from 2 to 8 weeks. Thus, wall motion abnormalities seen on 2-D echocardiography after transmural AMI often improve and wall motion returns to normal in some patients.

Adult↗
PubMed1985

Cardiac involvement in congenital myopathy.

We examined cardiac changes in 8 patients (4 men and 4 women, age 21-43 years) with congenital myopathy proven by skeletal muscle biopsy. Of 8 patients, 4 showed cardiac changes, including 1 with cytoplasmic body myopathy (patient 1), 2 with minimal change myopathy (patients 2 and 3) and 1 with nemaline myopathy (patient 4). Patients 1 and 2 showed left ventricular dilatation with severe global hypokinesis of left ventricular wall. These clinical features were quite similar to those of dilated cardiomyopathy and the patients were in NYHA class 3 or 4. Patient 3 had severe mitral regurgitation with mitral valve prolapse. This patient also had a persistent left superior vena cava and hypoplasia of the aorta, and her cardiac function was in NYHA class 3. Patient 4 showed moderate global left ventricular hypokinesis but the left ventricle was not dilated. This patient also had sino-atrial block and type A Wolff-Parkinson-White syndrome. His cardiac function was NYHA class 1. In conclusion, various types of congenital myopathy are associated with cardiac changes which can result in severe congestive heart failure.

Adult↗
PubMed1985

Noninvasive pulsed Doppler echocardiographic detection of the direction of shunt flow in patients with atrial septal defect: usefulness of the right parasternal approach.

Noninvasive pulsed Doppler echocardiography combined with two-dimensional echocardiography by the right parasternal approach was performed to detect the shunt flow through the defect in 31 patients with suspected secundum atrial septal defect (ASD). A defect of the interatrial septum was seen on the two-dimensional echocardiograms of 30 of 31 patients. In all the 30 patients, Doppler signals of shunt flow could be recorded by placing the sample volume in the center of the defect on the two-dimensional echocardiogram. Neither a defect nor Doppler signal indicating shunt flow were demonstrated in any of 15 normal control subjects. Cardiac catheterization indicated significant shunt flow in all the 31 patients with suspected ASD. Doppler signals obtained from the center of the defect showed left-to-right and/or right-to-left shunt flow patterns. The direction of the shunt flow was mainly left to right, with its peak in late systole and atrial systole in 28 of 30 patients; mainly right-to-left flow was present in the remaining two patients, who had Eisenmenger's syndrome. The direction of flow as predicted by the Doppler signal was confirmed by the coincidence of direction of flow as seen on the contrast two-dimensional echocardiogram. In 22 patients for whom the measurement of the pulmonary-to-systemic flow ratio by oximetry was believed to be reasonably accurate, the ratio was fairly well correlated with Doppler-determined left-to-right shunt flow velocity (r = .71, SEE = 6.7 cm/sec).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

[Systolic honk in mitral stenosis: a case report].

This case report describes a mitral systolic honk originating from the mitral valve and adjacent structures in a 52 year-old woman with mitral stenosis. The patient was hospitalized because of dyspnea. Auscultation of the heart revealed a grade 3/6 apical early systolic honk accompanied by an increased first heart sound, an opening snap and a diastolic rumble. The phonocardiogram demonstrated an early systolic honk at a frequency of 115 Hz. Intensity of the honk varied on beat to beat basis, increasing in the short preceding R-R interval compared to that in the long one. The M-mode echocardiogram showed early systolic fluttering of the mitral valve and chordae tendineae at the same frequency as the honk. The two-dimensional echocardiogram showed bulging of the anterior mitral leaflet toward the left atrium in early systole. After treatment with digitalis and diuretics, the early systolic honk disappeared in beats with preceding long R-R intervals (greater than 1100 msec). In beats without the honk, systolic fluttering of the mitral valve was not observed. The genesis of the early systolic honk is analogous to that of the honk audible in mitral or tricuspid valve prolapse. The bulging of the anterior mitral leaflet into the left atrium may produce vibrations of the mitral valve leaflets and adjacent structures.

Chordae Tendineae↗
PubMed1985

[Noninvasive estimation of pressure gradient in the left ventricular outflow tract: an experimental study].

The relationship between systolic anterior motion of the mitral valve (SAM) and left ventricular outflow pressure gradient (PG) was examined in five dogs with experimentally-produced SAM. A total of 155 heart beats including 29 post-extrasystolic beats with various PG were analyzed. Correlations of PG with the time from the onset of left ventricular ejection to the onset of SAM-septal contact (SSC), SSC divided by ejection time (ET) (SSC/ET), and SSC/ET multiplied by the pre-ejection period (PEP) (PEP X SSC/ET) were obtained. The relation between the natural logarithm of PG (InPG) and SSC/ET was expressed by the linear regression equation: InPG = -5.16X + 5.19, with the correlation coefficient (r) of -0.88 for total 155 beats (r ranged from -0.75 to -0.96 for each dog), and the relation between InPG and PEP X SSC/ET by the formula of InPG = -0.075X + 5.35, with the r of -0.91 for total 155 beats (r ranged from -0.84 to -0.95 for each dog). These results indicated that the time from the onset of aortic ejection to the onset of SAM-septal contact is strongly dependent on the degree of PG.

Animals↗
PubMed1984

[Detection of a shunt flow through a defect in secundum atrial septal defect by right parasternal approach using pulsed Doppler echocardiography].

Pulsed Doppler echocardiography combined with two-dimensional echocardiographic (2-DE) system was performed to detect a shunt flow through a defect in the interatrial septum (IAS) in patients with secundum atrial septal defect (ASD) utilizing right parasternal approach (RPA). RPA is a method which provides an accurate evaluation of a defect in the IAS on a 2-DE image by placing a transducer on the right of the sternum because the ultrasonic beam passes in a plane almost perpendicular to the IAS. The subjects consisted of 20 patients with ASD (25 +/- 22 yrs) diagnosed by cardiac catheterization or 2-DE with peripheral contrast material injection, and 10 cases of healthy subjects (34 +/- 18 yrs). Defects in the IAS were clearly visible in 19 patients with ASD on 2-DE images by RPA. By placing the sample volume in the center of the defect, Doppler flows could be obtained in 17 of them. In 13 with sinus rhythm, except a case of Eisenmenger syndrome, Doppler signals showed mainly a laminar flow toward the transducer (positive flow), but a transient flow of low velocity away from the transducer (negative flow) was also observed. The positive flow had its peaks in late systole and atrial systole and occasionally in mid-systole, early diastole and mid-diastole. The negative flow occurred in early systole, mid-diastole and late diastole. In a patient with Eisenmenger syndrome and tricuspid regurgitation (TR), a negative turbulent flow was observed from early systole to mid-diastole. In three patients with atrial fibrillation, Doppler signals were variable. The Doppler echogram of a patient with atrial fibrillation but no complication showed a laminar positive flow with its peaks in late systole and mid-diastole, and a negative flow in early systole. One patient with atrial fibrillation and TR had a systolic negative turbulent flow and a mid-diastolic laminar positive flow. In a patient with TR and mitral regurgitation, the Doppler echocardiogram showed a laminar positive flow throughout the entire cardiac cycle with its peaks in early diastole and mid-diastole. Doppler signals from the left atrium (LA) to the right atrium (RA) through a defect coincided in timing with the appearance of negative contrast echo from the defect to the RA on 2-DE image and signals from the RA to the LA coincided with the appearance of the contrast echo into the LA from the RA through the defect. Doppler signals disappeared after the closure of the defect in all six patients examined.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1984

[An experimental study on the relationship between interventricular septal echograms and interventricular pressure gradient].

To evaluate the correlation between the configuration and motion of the interventricular septum (IVS) and the interventricular pressure gradient, six closed-chest dogs were studied. M-mode and two-dimensional echograms, the left (LVP) and right ventricular pressures (RVP), the interventricular pressure gradient (LVP-RVP), phonocardiograms in the left and right ventricles and electrocardiograms were simultaneously recorded. The RVP was gradually elevated by injecting Lycopodium in a peripheral vein. In all six dogs, there were good correlations between the curvature of the IVS and the interventricular pressure gradient in end-systole and in end-diastole. In M-mode echograms of the IVS, three dips were recognized in early diastole (isovolumetric relaxation period, D1 dip), in late diastole (atrial kick, D2 dip) and in early systole (isovolumetric contraction, S1 dip) when the RVP was elevated. Three negative dips on interventricular pressure gradient curves were observed to occur simultaneously with D1, D2, and S1 dips, respectively. A D1 dip was demonstrated in all six dogs, a D2 dip in four dogs, and an S1 dip in six dogs. In conclusion, the curvature of the IVS reflects the change in the interventricular pressure gradients in diastole as well as in systole. D1, D2 and S1 dips in the IVS echogram also reflect changes in the interventricular pressure gradients.

Animals↗
PubMed1981

Electrocardiographic changes induced by the stellate ganglion block in normal subjects.

In order to examine the laterality of the sympathetic control of the human heart, electrocardiographic changes induced by a unilateral stellate ganglion block (SGB) were observed. 10ml of 1% lidocaine was used for the block and post-block ECG was recorded just after the appearance of Horner's sign. Patients who developed vocal hoarseness were excluded. 15 recordings of 14 subjects with right SGB and 16 recordings of 12 subjects with left SGB were used for analysis. A significant increase in the P-P interval from 0.90 +/- 0.17 sec to 0.96 +/- 0.16 sec. was observed only with right SGB and the predominance of the right side in the sympathetic nervous control of the human heart was thus demonstrated. The atrioventricular conduction time was not affected by either the right or left SGB. The QTc was slightly but significantly prolonged only by the right SGB, from 0.40 +/- 0.04 sec. to 0.43 +/- 0.04 sec. This prolongation was not large enough to support a definite conclusion and further investigations should be made.

Adult↗
PubMed1980

Motion of the interatrial septum in acute mitral regurgitation. Clinical and experimental echocardiographic studies.

The interatrial septal echocardiograms from 15 patients with acute mitral regurgitation due to ruptured chordae tendineae were compared with those from 14 normal subjects. On the cross-sectional echocardiogram, the interatrial septal configuration in patients with chordal rupture showed a characteristic pattern in which the interatrial septum (IAS) was flat or slightly convex toward the left atrium at end-diastole and became markedly convex toward the right atrium at end-systole. On the M-mode echocardiogram, the interatrial septal amplitude was greater in patients with chordal rupture (12.4 +/- 1.9 mm) than in normal subjects (9.4 +/- 0.9 mm). Systolic fluttering of the IAS was found in five of 10 patients with rupture of the chordae attached to the posterior mitral leaflet. This finding was thought to be specific for acute mitral regurgitation due to ruptured chordae to the posterior mitral leaflet. After operation, the amplitude of the IAS became normal or diminished and systolic fluttering of the IAS disappeared. Animal experiments performed to clarify the mechanism of these findings showed that increased systolic motion of the IAS resulted from an increased in the systolic left atrial-to-right atrial pressure gradient due to acute mitral regurgitation. The systolic fluttering of the IAS was thought to represent a jet stream against the IAS due to rupture of the chordae tendineae to the lateral half of the posterior mitral leaflet. We conclude that the interatrial septal echocardiogram reflects the hemodynamic changes due to acute mitral regurgitation and direction of the regurgitant jet against the IAS. This finding may prove to be important in diagnosing acute mitral regurgitation secondary to ruptured chordae tendineae.

Acute Disease↗
PubMed1978

Sympathetically induced atrial tachycardia. Successful treatment by left stellate ganglion block.

An unusual type of atrial tachycardia was observed in a 52-year-old woman. The tachycardia occurred only when the patient kept the left upper limb in the lateral and horizontal position. Propranolol, atropine sulfate, carotid sinus massage and ocular compression were not effective in terminating or preventing the arrhythmia. Left stellate ganglion block has stopped the tachycardia for at least two years. The atrial tachycardia in this patient was thought to be caused by mechanical stimulation of the left stellate ganglion resulting in pacemaker shifting, as has been demonstrated in the canine heart.

Action Potentials↗