Alvin J. Chin

Prenatal Diagnosis of Congenital Heart Defects in Thoracoabdominally Conjoined Twins

OPTIONS for the treatment of thoracoabdominally conjoined twins are largely dependent on the anatomy of the cardiovascular system.1 2 3 The extent of the conjunction of the heart and the severity of the associated cardiac defects primarily determine the feasibility of successful separation of the infants. Typically, the cardiovascular system is investigated first in the evaluation of thoracoabdominally conjoined twins. Only if the condition of the heart and associated structures is suitable for separation are the other organ systems, such as the gastrointestinal and urinary tracts, investigated. Definition of the cardiovascular anatomy in utero would facilitate prenatal counseling and perinatal management. Recent .xa0.xa0.

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.

Two-dimensional echocardiographic diagnosis of pulmonary artery sling in infancy

The vascular anomaly in which the left pulmonary artery arises from the right pulmonary artery and passes posteriorly and leftward between the trachea and the esophagus is termed a pulmonary artery sling. Two-dimensional echocardiograms were performed in five infants with this anomaly and successfully identified it in four, including one patient with truncus arteriosus communis. The subxiphoid long-axis sweep was useful in identifying the origin and initial course of the left pulmonary artery, and short-axis subxiphoid views showed both its origin from the right pulmonary artery and its initial posterior course. Angulation toward the cardiac apex displayed the right pulmonary artery in cross section anteriorly and the left pulmonary artery in cross section posteriorly. A transducer orientation midway between the subxiphoid long- and short-axis positions was helpful in distinguishing a large right upper lobe branch of the right pulmonary artery from a pulmonary artery sling. The precordial short-axis plane displayed the origin and initial posterior and leftward course of the left pulmonary artery, while the bifurcation of the main pulmonary artery, usually easily seen in this view, could not be demonstrated. Two-dimensional echocardiography offers a rapid, noninvasive diagnosis of pulmonary artery sling in infants.

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.

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.

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.

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.

Two-dimensional echocardiographic localization of residual atrial shunts after the Senning procedure

Abstract The most common complication of Mustard repair of transposition of the great arteries is a baffle leak, with incidence rates averaging approximately 20%. 1–3 Although there are fewer follow-up data for the Senning procedure, the incidence of residual atrial shunting is probably similar after both the Mustard and Senning procedures. 4 We investigated whether 2-dimensional (2-D) echocardiography can successfully localize the site of interatrial shunting following Senning repair.

Determination of Atrial Situs by Two-Dimensional Echocardiographic Imaging of Atrial Appendage Morphology

Until now, atrial situs has been inferred by two-dimensional echocardiographic (2-D echo) determination of: 1) the position of the abdominal aorta (AbdAo) and the inferior vena cava (IVC) relative to the spine, and 2) the pattern of hepatic venous connection (HVC) [1]. However, ascertaining atrial appendage morphology should be the most precise way of determining atrial situs [2–4].

Double-Outlet Left Ventricle: Echocardiographic-Pathologic Correlation and Surgical Implications

Double-outlet left ventricle (DOLV) is a rare cardiac anomaly that was first described in 1967. Several complex classification schemes have been reported [1–3]. Otero Coto [3] has pointed out the difficulty in making the correct preoperative diagnosis, even with axial angiography. Nevertheless, it is important to understand DOLV in detail, since most varieties are surgically correctable if recognized.