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Biomedical subjects

A J Chin

Publications and source records attributed to A J Chin.

67 records · Page 4Linked to original sources
PubMed1985

Subxiphoid two-dimensional echocardiographic identification of tricuspid valve abnormalities in transposition of the great arteries with ventricular septal defect.

Tricuspid valve morphology was examined using subxiphoid 2-dimensional echocardiography (2-D echo) in 39 infants aged 2 years or younger who had transposition of the great arteries (TGA) and ventricular septal defect (VSD) (group I). Age-matched control groups were 21 patients with simple TGA (group II), 30 patients with VSD and normally related great arteries (group III), and 15 normal patients (group IV). Valve abnormalities, consisting of chordal attachments to the infundibular septum or ventricular septal crest, straddling, overriding or some combination of these, were identified in 25 of 39 patients (64%) in group I, no patients in groups II or IV and 6 of 30 patients (20%) in group III. Intraatrial baffle repair was performed in 27 patients in group I (median age at surgery 3.5 months) and 19 patients in group II (median age 4 months). Preoperative right ventricular angiography, performed in all patients with TGA, demonstrated tricuspid regurgitation (TR) with biventricular dysfunction in 1 patient in group I. After surgery, TR was present in 9 of 17 group I patients and none of the 8 group II patients who underwent catheterization. All patients in whom TR was not present preoperatively had abnormal chordal attachments; 3 required valve replacement. These results demonstrate that tricuspid valve abnormalities are common in patients with TGA and VSD and may be identified preoperatively using 2-D echo. Patients with abnormal chordal attachments are at increased risk for TR after intraatrial baffle repair and should be considered for arterial switch repair.

Cardiac Catheterization↗
PubMed1985

Accuracy of prospective two-dimensional echocardiographic evaluation of left ventricular outflow tract in complete transposition of the great arteries.

Thirty-two consecutive infants with transposition of the great arteries (TGA) and ventricular septal defect underwent subxiphoid 2-dimensional echocardiography (2-D echo). Two independent observers prospectively evaluated each echocardiogram for the presence or absence of left ventricular (LV) outflow tract obstruction, whether outflow obstruction was dynamic or fixed, or both, and the precise anatomic type of fixed obstruction. Compared with the LV-to-pulmonary artery gradient determined at cardiac catheterization, 2-D echo yielded low false-negative (7 to 13%) and false-positive (0 to 6%) rates for diagnosing the presence or absence of LV outflow tract obstruction. Moreover, the false-negative cases were only minor errors, because the measured LV-pulmonary artery gradients proved to be less than 25 mm Hg. Compared with the long-axial oblique LV angiogram, 2-D echo yielded no false-negative results in detection of outflow tract obstruction, which was at least partly fixed. Compared with autopsy/surgical observation, 2-D echo made no significant errors in delineating the exact anatomic type of fixed obstruction. The diagnostic accuracy of 2-D echo in detecting and characterizing LV outflow tract obstruction limits the need for "routine" cardiac catheterization before repair in infants with TGA and intact ventricular septum. Furthermore, because certain types of fixed LV outflow tract obstruction are difficult for the surgeon to visualize and alleviate, precise knowledge of the anatomic type of fixed obstruction influences the choice among Rastelli, intraatrial baffle and arterial switch procedures in patients with TGA and ventricular septal defect.

Cardiac Catheterization↗
PubMed1983

Two-dimensional echocardiographic assessment of caval and pulmonary venous pathways after the senning operation.

This study reports the 2-dimensional echocardiographic appearance of the caval and pulmonary venous pathways after the Senning procedure in 28 patients and establishes normal values for the caval and pulmonary venous pathway dimensions. Eighteen patients had no caval or pulmonary venous obstruction or tricuspid regurgitation at catheterization; 2 had isolated superior vena caval obstruction, 3 had isolated pulmonary venous obstruction, 4 patients had severe tricuspid regurgitation, and 1 had a large residual ventricular septal defect. The caval and pulmonary venous pathways were imaged in modified 4-chamber and transverse views, and the narrowest dimension of each pathway in each view was measured by 2 independent observers. Dimension measurements were then normalized to the cube root of body surface area. Caval and pulmonary venous pathway "dimension products" were obtained by multiplying the normalized dimension in the 4-chamber view by the normalized dimension in the transverse view. All patients with catheterization-proven caval or pulmonary venous obstruction or tricuspid regurgitation had caval or pulmonary venous pathway dimension products outside the normal range, defined by our measurements in the 18 patients with no caval or pulmonary venous obstruction or tricuspid regurgitation. Thus, 2-dimensional echocardiography can provide both quantitative and qualitative information about the caval and pulmonary venous pathways after the Senning procedure.

Child↗
PubMed1983

2-dimensional echocardiographic appearance of complete left-sided juxtaposition of the atrial appendages.

This report describes the 2-dimensional (2-D) echocardiographic appearance of left-sided juxtaposition of the atrial appendages (JAA). From January 1, 1978, to June 30, 1979, 2 infants had the diagnosis of left-sided JAA at autopsy. Both patients had previously been examined by subxiphoid 2-D echocardiography. On review of these studies, the septum secundum was found to be oriented posteriorly in the transverse view of the atria. From July 1979 to June 1981, prospective evaluation of all infants for the presence of this finding revealed 2 more patients. Left-sided JAA was confirmed at surgery in 1 case and by selective right atrial angiography in the other. The diagnosis of left-sided JAA has important implications for both atrial baffle operations and for the Fontan procedure.

Echocardiography↗
PubMed1983

Subxyphoid 2-dimensional echocardiographic identification of left ventricular papillary muscle anomalies in complete common atrioventricular canal.

Mitral valve dysfunction is probably the major cause of operative mortality from total repair of complete common atrioventricular (AV) canal in infancy. The presence of a solitary left ventricular (LV) papillary muscle appears to be 1 anatomic factor influencing the success of mitral reconstruction because suturing of the cleft between the superior and inferior components of the anterior mitral leaflet creates a parachute mitral valve deformity, which may result in stenosis or in unduly high tension on the components of the repair. This study reports on (1) the 2-dimensional (2-D) echocardiographic appearance of the LV papillary muscle architecture in patients with complete common AV canal compared with that in normal subjects, and (2) the incidence of solitary LV papillary muscle in patients with complete common AV canal. Two-dimensional echocardiography was performed in 31 infants with complete common AV canal, 14 normal infants, and 9 infants with a large ventricular septal defect not involving the AV canal region. Of 31 infants with complete common AV canal, 26 (80%) had 2 LV papillary muscles on 2-D echocardiography, 3 (10%) had 3 LV papillary muscles, and 3 (10%) had 1 LV papillary muscle. In patients with 2 LV papillary muscles, the anterolateral papillary muscle was displaced posteriorly compared with that in normal subjects and in patients with ventricular septal defect, whereas the posteromedial papillary muscle was in its normal location. Among the 25 patients with complete common AV canal with 2 LV papillary muscles, there was 1 operative death. Among the 6 infants with complete common AV canal with LV papillary muscle anomalies, 5 underwent surgical repair with 4 early deaths. Subxyphoid 2-D echocardiography is a useful technique for evaluating LV papillary muscle architecture in complete common AV canal and permits identification of patients who may be at higher risk for unsuccessful mitral reconstruction.

Echocardiography↗
PubMed1982

Repair of complete common atrioventricular canal in infancy.

Forty-three infants with common atrioventricular canal (CAVC) underwent repair before 24 months of age at Children's Hospital Medical Center, Boston, between Jan. 1, 1975, and June 30, 1980. From 1975 to 1977, the operative mortality was 62% (8/13); the late mortality was 7% (1/13). From 1978 to 1980, the operative mortality was 17% (5/30) and the late mortality, was 6% (2/30). Seventeen (63%) unselected patients of the 27 long-term survivors have undergone cardiac catheterization 10 to 19 months following the operation. Five (29%) had mitral regurgitation of either moderate (four) or severe (one) degree. One had a significant residual shunt. The pulmonary/systemic resistance ratio (Rp/Rs) remained the same or decreased after repair except in the patient with severe mitral regurgitation. Anatomic features which determine outcome of reparative procedures are (1) deficiency of atrioventricular valve tissue, (2) the presence of ventricular hypoplasia, (3) malalignment of the common atrioventricular valve (CAVV) with respect to the ventricles, (4) the presence of double-orifice mitral valve, (5) the presence of solitary left ventricular papillary muscle group, and, in our experience, (6) the presence of additional muscular ventricular septal defects (VSDs). Four of these six anatomic variables can now be evaluated preoperatively by axial angiography and subxiphoid two-dimensional echocardiography. However, the architecture of the CAVV is extremely variable, so that the development of a "uniform approach" to valve reconstruction is impossible; mitral dysfunction is likely to remain the major cause of operative mortality and long-term morbidity.

Cardiac Catheterization↗
PubMed1981

Cardiovascular abnormalities in thoracopagus twins.

A detailed anatomopathologic study of the various developmental malformations encountered in a set of female thoracopagus twins is presented. Special emphasis has been devoted to the analysis and description of the complex cardiovascular abnormalities associated with the conjoined heart and liver of this set of twins. The heart was conjoined with two sets of great arteries. The great arteries of one twin were d-malposed and originated from a single right ventricle; a normally placed aorta originated from a single left ventricle and the hypoplastic pulmonary trunk originated from a rudimentary outlet chamber of the other twin. One twin had two atria with the systemic veins returning to the right one and an anomalous pulmonary venous return terminating in the ductus venous of her liver. The other twin had a single right atrium plus an accessory atrial chamber to which both the pulmonary and the systemic veins returned. There were two umbilical arteries originating from the internal iliac arteries of one twin and two umbilical veins which fused into one as they entered into the ductus venous of the other twin. The cardiovascular abnormalities of our case have been compared with those encountered in 25 well-documented cases of thoracopagus twins previously reported in the literature. It was concluded that the majority of thoracopagus twins (approximately 75%) had conjoined heart with associated cardiovascular abnormalities making them unsuitable for surgical separation even at the cost of the life of one of them. In addition, an embryological interpretation concerning the possible origin of the cardiovascular abnormalities of our case is presented and discussed.

Aorta↗
PubMedDate not supplied

Early experience and the consumption of alcohol by adult C57BL/6J mice.

Two types of early experience were examined for their effect on voluntary alcohol consumption by adult C57BL/6J mice: the experiences associated with belonging to a particular litter, and the experience of early postweaning choice between water and a 10% alcohol solution. Males from identified litters were individually caged from arrival at three weeks of age and given a choice between 10% alcohol and water when eight weeks old. Another group without notation of litter was given alcohol-water choice upon arrival at three weeks of age. Alcohol intake was examined by three measures: daily licks of 10% alcohol, alcohol selection (percent alcohol drinking), and volume of alcohol drunk daily. Belonging to a particular litter did affect body weight and growth, but had no effect on adult consumption of alcohol. Postweaning exposure to alcohol choice, however, produced a small but significant and prolonged increase in alcohol consumption by adults. Furthermore, a developmental trend was found in mice offered alcohol choice at an early age: alcohol preference developed as postweaning growth slowed.

Aging↗
PubMedDate not supplied

Noninvasive imaging of intraarterial baffles in infants and children.

Baffles within the lumen of the pulmonary artery are created in (1) the Aubert procedure, a variation of the arterial switch favored by some surgeons when two major coronary ostia arise close to one another or when one coronary artery has an intramural course, and (2) the Takeuchi procedure, a technique applied to patients with anomalous origin of the left coronary from the pulmonary artery. In both operations, coronary artery transplantation is avoided; instead, an aorticopulmonary window is created and aortic blood is redirected by an intrapulmonary artery baffle into the coronary circulation. We imaged five patients with Aubert and 10 patients with Takeuchi procedures by use of ultrasound to assess the sequelae of such intraarterial baffles. All five Aubert patients were < 3 weeks old; the ages of the 10 Takeuchi patients ranged from 2 to 86 months. Two patients died early after surgery; the remaining 13 patients were observed for 3 to 83 months (median 46 months). In all 15 patients, the baffle geometry was visualized and the aorticopulmonary window was identified. In the six who had serial imaging, none developed aorticopulmonary window stenosis. In no patient was any peribaffle shunting detected. Supravalvar narrowing, caused by the baffle partially obstructing the neopulmonary artery, was observed in two of five Aubert patients; in only one of these has reoperation been performed. In one of the 10 Takeuchi patients supravalvar narrowing of the pulmonary artery (related to repair of coexistent tetralogy of Fallot) has developed and the patient has since undergone reoperation.

Child, Preschool↗
PubMedDate not supplied

Morphology of the ventricular septal defect in two types of interrupted aortic arch.

Whether coarctation or interruption (IAA) of the aorta, ostensibly similar in morphology (and management), result from the same or different developmental errors can be inferred by examining the pattern of associated anomalies. Among the most common associated lesions, especially in IAA, is ventricular septal defect (VSD). Although muscular and perimembranous VSDs are the most common in aortic coarctation, the prevalence of various VSD morphologies in IAA has not been examined in as much detail. As part of the recent prospective multiinstitutional study of IAA conducted by the Congenital Heart Surgeons Society, 53 echocardiographic studies were reviewed; 42 of 45 patients with type B IAA had VSDs involving maldevelopment of the outflow region. In type A IAA, a significantly lower percentage (4/8) had this kind of VSD. Therefore the mechanism of development of type B IAA is likely to be different from that of type A IAA.

Aorta, Thoracic↗
PubMedDate not supplied

Noninvasive evaluation of newborns with congenital heart disease.

Over the last decade, diagnosis and management of neonates with congenital heart disease have been greatly influenced by the constant expansion of noninvasive methods. We classify the most common congenital defects presenting in the first 2 weeks of life, based on clinical presentation and hemodynamic characteristics, followed by a discussion of echocardiographic findings in the most common congenital heart lesions and how ultrasound techniques can help solve problems frequently encountered during the early postoperative period.

Echocardiography↗