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Biomedical subjects

C Tei

Publications and source records attributed to C Tei.

At least 145 records · Page 8Linked to original sources
PubMed1983

Degenerative calcific valvular disease and systolic murmurs in the elderly.

By use of echocardiographic and radiologic imaging, a prospective study was made of 98 elderly men, 65 to 102 years old, to define degenerative calcific valvular disease (DCVD)--its prevalence, morphologic features, functional significance, and relationship to systolic murmurs in the elderly. DCVD was diagnosed in 74 per cent of the group and murmurs were detected in 55 per cent, the incidences increasing with age. Fibrotic and calcific change of the aortic valve was the most common abnormality, occurring alone or together with alteration of the mitral valve. The murmurs were characteristically early systolic, of low intensity and medium pitch, and heard at more than one area. Of the group with valve degeneration, only 7 per cent was judged to be functionally significant and no more than moderate. It was concluded that DCVD is the cause of most systolic murmurs in the elderly and is usually hemodynamically unimportant. Echocardiographic criteria are important in identifying those subjects with possibly significant valvular dysfunction requiring invasive study.

Aged↗
PubMed1983

Myocardial contrast echocardiography: a reproducible technique of myocardial opacification for identifying regional perfusion deficits.

The effects and reliability of a simple method of contrast two-dimensional echocardiographic delineation of myocardium after intracoronary injections were evaluated in closed-chest dogs. Multiple injections of an agitated saline-Renografin (meglumine diatrizoate) mixture (3:2 ratio, 2-ml bolus) into the left main coronary artery as well as at different sites of the left anterior descending and circumflex coronary arteries were studied in several short-axis and long-axis cross sections of the left ventricle. These contrast injections opacified specific regions of left ventricular myocardium depending on the site of injection. Contrast injection into the left main coronary artery provided a clear, echo-free outline (negative contrast) of underperfused myocardium distal to the coronary occlusion. Reproducibility studies of the extent of involved zones measured in echocardiographic cross sections indicated high intra- and interobserver correlation coefficients (r = 0.97 and 0.97). The effects of the intracoronary injection of contrast material appeared minor and brief. ECG ST-T changes lasted 49.4 +/- 36.7 seconds, aortic systolic pressure was reduced by 7.6 +/- 4.4% for 18.9 +/- 4.8 seconds, and the peak rate of left ventricular pressure rise decreased by 14.3 +/- 2.6%, but returned to control levels within 19.4 +/- 6.1 seconds. The zone of left ventricular asynergy after coronary occlusions was also delineated by cross-sectional echocardiography and corresponded to the contrast-outlined underperfused zone (negative contrast). This new intracoronary echocardiographic technique has only minor hemodynamic consequences and provides reliable quantitation of underperfused and dysfunctioning zones after experimental coronary occlusions. Further investigation and validation of this method may provide useful characterization of the extent and severity of myocardial ischemia and infarction.

Animals↗
PubMed1983

A regurgitant jet and echocardiographic abnormalities in aortic regurgitation: an experimental study.

Acute aortic regurgitation was created experimentally in 21 mongrel dogs to examine the relationship of the regurgitant jet to observed echocardiographic findings. The direction of the regurgitant jet was studied by echo contrast injections in the aortic root. Diastolic fluttering of the anterior mitral leaflet (AML) was noted in all 21 dogs irrespective of direction of the jet. Diastolic fluttering of the interventricular septum (IVS) was noted in six of the seven dogs with a tear of the noncoronary cusp and in one of seven dogs with lesions in the left coronary cusp. In all seven dogs with echocardiographically demonstrated IVS fluttering, a regurgitant jet impinged on the anterior part of the IVS. Amplitude of the AML excursion was not significantly different from control when the lesions involved the noncoronary or the left coronary cusps. However, all seven dogs that had a lesion in the right coronary cusp demonstrated a significant reduction in the amplitude of the AML excursion. The regurgitant jet in these dogs impinged uniformly on the AML. We conclude that diastolic fluttering of the AML is uniformly observed and unrelated to the direction of the regurgitant jet, diastolic fluttering of the IVS is caused by the regurgitant jet impinging upon the IVS, and amplitude of the AML may be reduced as a result of a jet impingement of the AML.

Animals↗
PubMed1983

Mitral valve prolapse in short-term experimental coronary occlusion: a possible mechanism of ischemic mitral regurgitation.

Experimental coronary occlusions were carried out in 12 closed-chest dogs to investigate the functional anatomic characteristics of the mitral valve complex during acute myocardial ischemia. Two-dimensional echocardiography was used to assess left ventricular function, the mitral valve complex, and left atrial size. Presence of mitral regurgitation was assessed by left ventricular contrast echocardiography. Thirty-seven coronary occlusions of up to 10 min in duration were carried out in proximal or distal locations in the left anterior descending and the left circumflex coronary arteries. Mitral regurgitation, which was mild in severity as judged by a small rise in pulmonary artery wedge pressures, was observed in 15 of 37 brief coronary occlusion experiments. Mitral valve prolapse was noted in all 15 experiments, as well as in four additional studies in which mitral regurgitation was not seen. The development of experimental mitral valve prolapse was explained by measurements that demonstrated a relative displacement of the papillary muscle tips toward the mitral orifice. We conclude that mitral valve prolapse is a common sequela of short-term coronary occlusion and is often associated with mild mitral regurgitation. Relative displacement of ischemic papillary muscles toward the mitral orifice appears to be a likely mechanism of acute ischemic mitral valve prolapse.

Animals↗
PubMed1983

Sensitivity and specificity of two-dimensional echocardiography in the detection of valvular calcification.

To test the ultrasonic method for detecting valvular calcifications, two-dimensional echocardiograms and 35-mm cinefluorograms recorded in 113 elderly men were compared. Four views of the heart were filmed with image intensification. Valvular opacifications 1.5 mm or more in diameter were considered to be calcium and served as the standards. From parasternal views the brightness of valvular echoes was compared to echoes of the aortic wall by incremental rejection. Valvular echoes persisting as long as or beyond suppression of aortic root echoes were called positive for calcium. In half of the subjects, fluorographic studies disclosed valvular calcium, of which 67 percent was graded minimum. Echocardiographic sensitivity for detecting calcium in both the mitral anulus and aortic valve was 76 percent; specificity was 89 to 94 percent. Detection in the mitral leaflets was low and due to the smallness of the target and high sensitivity of the standard. Thus, an easily performed ultrasonic technique can screen moderate calcification of the mitral annulus and aortic valve with a predictive accuracy of 80 percent.

Aged↗
PubMed1982

The correlates of an abnormal first heart sound in mitral-valve-prolapse syndromes.

In 52 patients with mitral-valve prolapse we studied the intensity of the first heart sound (S1) in relation to the timing of the prolapse and to the presence of leaflet tip coaptation. Sixteen normal subjects served as controls. With two-dimensional echocardiography, three distinct groups were identified. Sixteen patients had early systolic mitral prolapse coincident with initial mitral-leaflet coaptation at the S wave on electrocardiography. Twenty-one had middle to late systolic mitral prolapse. Fifteen had flail mitral leaflet without normal leaflet coaptation at the free margins. The intensity of S1 was expressed as the ratio of the S1 amplitude to that of the aortic component of the second heart sound. This ratio was greater in the patients with early prolapse (6.2 +/- 3.1, mean +/- S.D.) than in the controls (1.4 +/- 0.7) (P less than 0.01). The ratio was reduced in patients with flail valves (0.3 +/- 0.5) (P less than 0.01) and did not differ between patients with middle to late prolapse (1.3 +/- 0.6) and controls. We conclude that the amplitude of S1 may provide a clue to the type and timing of mitral-valve prolapse.

Adolescent↗
PubMed1982

Assessment of tricuspid regurgitation by directional analysis of right atrial systolic linear reflux echoes with contrast M-mode echocardiography.

Twenty-seven individuals were studied for diagnostic assessment of tricuspid regurgitation (TR) using directional analysis of echo contrast lines on M-mode echocardiograms (MME). Group I consisted of 12 patients with physical findings, as well as phonocardiogram and jugular venous pulse tracings, compatible with TR. Group II consisted of five normal volunteers and 10 control patients without any evidence of congestive heart failure or TR. Following peripheral venous injection of contrast material, all 12 patients in group I demonstrated linear reflux contrast echoes in the right atrium (RA) on MME consisting of multiple posteriorly directed echo lines throughout systole behind the tricuspid valve. In addition, linear reflux contrast echoes in the hepatic vein directed away from its entry into the inferior vena cava were noted in 8 of the 12 patients by a cursor-placed MME. The remaining 15 patients in group II showed none of the above findings on contrast echocardiography. These observations indicate that linear systolic reflux contrast echoes in the RA behind the tricuspid valve on MME may be a specific and sensitive sign of TR.

Diastole↗
PubMed1982

The tricuspid valve annulus: study of size and motion in normal subjects and in patients with tricuspid regurgitation.

The tricuspid valve leaflets and their annular attachments were recorded by two-dimensional echocardiography from a view of the right ventricular inflow tract obtained by placing the transducer at an intermediate position between the left ventricular apex and the left lower sternal border. The transducer was rotated, and recordings were made at 30 degrees rotational intervals around the circumference of the tricuspid valve annulus. The cyclical pattern of variations in tricuspid annular size was studied with 12 measurements made during the cardiac cycle in five normal subjects. Annular areas and circumferences were measured. The overall motion pattern was similar to that reported in normal mitral valve annular study. Subsequently, in 16 normal subjects and 18 patients with tricuspid regurgitation, the maximum and minimum tricuspid annular sizes and their percent reduction were measured. The mean maximum annular circumference and area were 11.9 +/- 0.9 cm (mean +/- SD) and 11.3 +/- 1.8 cm2 in normal subjects. They were significantly greater in tricuspid regurgitation (14.0 +/- 0.7 cm and 15.8 +/- 1.8 cm2, respectively). The mean minimum annular sizes were much larger in tricuspid regurgitation (12.5 +/- 0.6 cm and 13.0 +/- 1.4 cm2) than in normal subjects (9.6 +/- 0.9 cm, 7.6 +/- 1.4 cm2). Thus, the percent reduction of annular circumference and area were significantly decreased in tricuspid regurgitation. For anatomic correlations, measurements of the tricuspid annular circumference were made at autopsy in 18 hearts without underlying valvular disease. The annular circumference was measured in the fresh and fixed states. The measurement in the fresh state was 13.5 +/- 0.8 cm and in the fixed state was 12.0 +/- 0.8 cm. The values measured in the fixed hearts were more similar to measurements obtained by echocardiography in a group of normal subjects. Thus, tricuspid annular reconstruction by the new two-dimensional echocardiographic method provides additional information about normal and abnormal size and function of the tricuspid valve annulus.

Adult↗
PubMed1981

Size and motion of the mitral valve annulus in man. I. A two-dimensional echocardiographic method and findings in normal subjects.

Using wide-angle, phased-array, two-dimensional echocardiography, mitral leaflets and their annular attachments were recorded from a view close to the standard apical four-chamber view. The transducer was rotated and recordings were made at 30 degrees rotational intervals around the circumference of the mitral valve annulus. To reconstruct the annulus, the diameters (chords) from each rotational interval were arranged around a reference point. This was done for 12 times during the cardiac cycle. Annular areas were planimetered and circumferences measured. Correlation was good for areas reconstructed and measured by the same observer on separate occasions (r = 0.963) and by two different observers (r = 0.987). In 11 normal subjects the annular area index (area divided by body surface area) increased during diastole to a maximum of 3.8 +/- 0.7 cm2/m2 (mean +/- SD) in late diastole. There was presystolic followed by systolic narrowing to a minimum in midsystole. The mean reduction in area was 26 +/- 3%. The maximal annular circumference was 9.3 +/- 0.9 cm and the mean reduction in circumference was 13 +/- 3%. The overall motion pattern was similar to that reported in experimental studies in the dog. Mitral annular reconstruction may provide new information about normal and abnormal function of the mitral valve apparatus.

Diastole↗
PubMed1981

Hemodynamic determinants of pulmonary valve motion during systole in experimental pulmonary hypertension.

To clarify the determinants of pulmonary valve (PV) motion in pulmonary hypertension, we examined the correlations among PV echo patterns, the pulmonary artery (PA) flow curve just above the PA orifice and the pulmonary artery-right ventricle (PA-RV) pressure gradient. By constricting the PA, we could produce a variety of PV echo patterns, including midsystolic semiclosure in open-chest dogs. Throughout the experiments, the PV echo pattern and PA flow curve were similar in pattern and timing. When the PV echo showed midsystolic semiclosure with reopening. The PA flow curve showed a transient decrease followed by a transient increase during midsystole. The PA-RV pressure gradient became transiently positive (PA pressure greater than RV pressure) and then negative in midsystole only when the PV echo showed midsystolic semiclosure with reopening. In conclusion, PV motion during systole may be instantaneously determined by PA flow change and the PA-RV pressure gradient during the cardiac cycle in experimental pulmonary hypertension.

Animals↗
PubMed1980

Diastolic bulging of the interventricular septum toward the left ventricle. An echocardiographic manifestation of negative interventricular pressure gradient between left and right ventricles during diastole.

Diastolic bulging of the interventricular septum (IVS) toward the left ventricle was observed by real-time cross-sectional echocardiography in three patients with primary pulmonary hypertension and one patient with secondary pulmonary hypertension after closure of an atrial septal defect. M-mode echocardiography showed a characteristic abnormal pattern of septal motion in diastole and in systole. In two patients, we attempted to correlate M-mode motion to the interventricular pressure gradient. During diastole, the interventricular pressure gradient between the left and right ventricles was negative and the pressure gradient curve was very similar to the M-mode echogram of the IVS. Banding studies in which acute right ventricular hypertension was produced in dogs showed similar shape changes, suggesting that the diastolic shape and motion of the septum are determined by the interventricular pressure gradient between the ventricles. Diastolic bulging of the IVS toward the left ventricle in our patients results from negative interventricular pressure gradient between the left and right ventricles during diastole.

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↗