Complete transposition of the great arteries and coarctation of the aorta

Thirty-two patients with complete transposition of the great arteries (TGA) and coarctation of the aorta (C of A) were seen at The Hospital for Sick Children, Toronto, Canada, between 1963 and 1983. Three patients had only mild C of A and have not required coarctectomy (Group I); 29 had a severe form of C of A (Group II). Two patients in Group I and 21 in Group II had a ventricular septal defect. Subaortic obstruction was present in 5 patients in Group II. The mechanisms included anterior deviation of the infundibular ventricular septum, anomalous right ventricular muscle bundles, and abnormal ventriculoinfundibular fold. Five patients in Group II had a hypoplastic right ventricle. Coarctectomy was performed in 25 patients, and 5 died (20% mortality rate). Sixteen patients had repair for TGA (13 Mustard, 2 Jatene, 1 Rastelli), and 2 died (12% mortality rate). Life-table analysis shows that only 68% of the patients with TGA and C of A survived the first month of life. The 5-year survival in this group was 57%. In the same period, 94% of patients with uncomplicated TGA survived the first month of life and the 5-year survival rate was 89%.     

Echocardiographic evaluation of right ventricular function in complete transposition of the great arteries: angiographic correlates.

Right ventricular function of patients with complete transposition of the great arteries may be impaired. To assess whether the M mode echocardiogram could predict right ventricular function 64 echocardiograms and ventricular angiograms of 62 patients were studied, 33 obtained before repair of the defect (group I) and 31 (including 2 from patients in group I) obtained after the Mustard procedure (group II). Each group was subdivided according to whether a ventricular septal defect or patent ductus arterposus was or had been present preoperatively.The right ventricular preejection period was expressed as the ratio of the observed to the predicted value for a systemic left ventricle. This value was above normal In all groups and was not significantly different in the 13 patients with right bundle branch block. The observed ejection time expressed as a percent of that predicted for a systemic left ventricle correlated with right ventricular ejection fraction (r = 0.47). The ratio of the observed preejection period/ejection time had a higher correlation with right ventricular ejection fraction (r = ? 0.70). Nine patients had a low right ventricular ejection fraction (an ejection fraction of 0.55 or less was considered indicative of poor right ventricular function). These nine patients were all in group II and all had right bundle branch block.Most patients with poor right ventricular function had had a ventricular septal defect or patent ductus arteriosus before repair of the transposition, and postoperatively had angiographic tricuspld regurgitation, right bundle branch block, a preejection period/ejection time ratio greater than 0.55 and a percent predicted ejection time of 96 percent or less. Most patients who had good right ventricular function (ejection fraction greater than 0.55) had none of these findings. Systolic time intervals obtained with M mode echocardiography can be used for the assessment and longitudinal follow-up of right ventricular function in patients with transposition.     

Congenital unilateral pulmonary vein stenosis complicating transposition of the great arteries

Four patients with transposition of the great arteries and unilateral pulmonary vein (PV) stenosis, all left-sided, were studied. Two patients had an intact ventricular septum (1 with a patent ductus arteriosus), 1 patient had a ventricular septal defect and 1 had a ventricular septal defect with pulmonary stenosis. Clinical signs, such as recurrent pneumonia, unilateral pulmonary edema and pleural effusion, were present preoperatively in 2 patients. Diagnosis was made at cardiac catheterization by cineangiography in 2 patients and at Mustard operation when the PV orifices were inspected in the other 2. PV dilatation was attempted in 3 patients, 1 before correction (age 6 months), 1 during and after it (ages 1 and 3 years, respectively) and 1 during corrective surgery (age 15 months). In the fourth patient only the intracardiac baffle was enlarged near the left PV orifices. In the first patient, at Mustard operation (age 18 months), only a fibrotic PV without an orifice was found; this patient died after surgery. The mean follow-up in the 3 survivors was 3.2 years (range 2 months to 7.6 years). All have severe residual PV obstruction documented by technetium-99m lung perfusion scans that show decreased flow to the left lung (0 to 16% total counts; normal 45 %); 2 have unilateral pulmonary edema and 1 has pulmonary artery pressure at systemic level. It is believed that in patients with transposition of the great arteries, left-sided unilateral PV stenosis is a congenital anomaly that becomes progressive as a result of postnatal preferential flow to the right lung.     

Role of the renin-angiotensin-aldosterone system in hypertensive children with coarctation of the aorta.

To investigate the role of the renin-angiotensin-aldosterone system as a cause of hypertension, 20 hypertensive patients with coarctation of the aorta were studied during normal and low sodium intake and after diuresis with flurosemide. Eight patients with essential hypertension and 13 control subjects were similarly studied. Plasma renin activity values in patients with coarctation were similar to those in patients with essential hypertension and in control patients during normal and low sodium diets. However, after the administration of furosemide, plasma renin activity values were significantly higher in the patients with coarctation than in the other two groups (P less than 0.005 and less than 0.01, respectively). The values for urinary aldosterone, plasma volume and extracell fluid volume (bromide space) were increased in patients with coarctation during both normal and low sodium intake. These renin and aldosterone responses and body fluid spaces in patients with coarctation suggest that their hypertension resembles a one-kidney Goldblatt model. The data help to better define the role of the renin-angiotensin-aldosterone system in the hypertension of coarctation and thus may help guide the clinician in therapeutic interventions.     

Prediction of left ventricular pressure from the vectorcardiogram in transposition of the great arteries

Eighty-two cardiac catheterizations were performed in 72 children with complete transposition of the great arteries; vectorcardiograms (Frank lead) and orthogonal electrocardiograms were obtained in all cases within 24 hours. Fifty-six of these studies were performed in children with an additional ventricular septal defect, and 26 in children with an intact ventricular septum. There was a significant correlation between the ratio of the right and left maximal spatial vectors and the S/R ratio in lead X of the orthogonal lead electrocardiogram. A clockwise loop in the horizontal vector or an S/R ratio of more than 2:1 suggested decreased left ventricular pressure, whereas a counterclockwise or figure-of-8 loop in the horizontal plane or an S/R ratio of less than 2:1 in lead X of the orthogonal electrocardiogram suggested increased left ventricular pressure. Nineteen additional patients with transposition of the great arteries were studied in the same way. With use of the direction of rotation of the horizontal loop and the S/R ratio in lead X, left ventricular pressure was correctly predicted in 84 percent of cases.

After cardiac catheterization has established the diagnosis of transposition of great arteries, repeat vectorcardiograms should be obtained to determine left ventricular pressure. In a patient with initially decreased left ventricular pressure, change to a figure-of-8 or counterclockwise loop or the presence of an S/R ratio in lead X of less than 2.0 suggests the development of a systemic level of left ventricular pressure. This finding is an indication for repeat catheterization.     

Differentiation of functional and structural pulmonary atresia: Role of aortography

Among certain critically ill neonates with severe tricuspid regurgitation, including those with Ebstein's anomaly of the tricuspid valve, tricuspid valve dysplasia, transient tricuspid regurgitation of the newborn, Uhl's anomaly and hypoplasia of the right ventricle, selective right ventriculography may not distinguish between patients with associated functional and those with structural pulmonary atresia. In patients with a normal pulmonary valve and infundibulum, functional obstruction (nonvisualization of the pulmonary artery on right ventricular angiography when the pulmonary valve is anatomically patent and nonobstructive) results from a combination of massive tricuspid insufficiency and increased perinatal pulmonary vascular resistance. This differentiation between functional and structural pulmonary atresia is essential because of the therapeutic implications.In 33 neonates studied at cardiac catheterization from January 1974 through October 1977 standard hemodynamic measurements and right ventriculograms could not distinguish between functional and structural pulmonary atresia. Retrograde aortography, in the presence of a patent ductus arteriosus, provided excellent visualization of the pulmonary root and valve in these cases and, without exception, pulmonary regurgitation across the valve was observed in the patients with functional pulmonary atresia. Usually, the amount of regurgitated contrast material was dense and both the right ventricle and the right atrium were opacified. In addition, among the patients with functional pulmonary atresia, the pulmonary root and valve appeared wider and more patulous than in the patients with structural pulmonary atresia and normal or mildly increased right ventricular pressure was appreciated.     

Coarctation of the aorta or subaortic stenosis with atrioventricular septal defect

Thirty patients are reported with atrioventricular (AV) septal defect and either coarctation of the aorta (C of A) or subaortic stenosis (SAS) or both. All patients had normal left ventricles as assessed by angiography (21 of 30 patients) or necropsy (9 of 30). Three groups were recognized. Groups I and II included 19 patients with AV septal defect (12 complete, 7 partial) and C of A with or without SAS, 11 patients with AV septal defect (5 complete, 6 partial) and SAS. In Group I, preductal C of A was diagnosed in 16 of 19 patients. Concomitant angiographic evidence of SAS was present in 2 cases, the mechanism being exaggerated anterior displacement of the left AV valve. In Group III, at the time of diagnosis left ventricular-aortic peak systolic pressure gradients of greater than 20 mm Hg were present in 9 patients, 2 of whom had gradients greater than 50 mm Hg. Angiographic diagnoses were: discrete fibrous diaphragm in 4, fibromuscular obstruction in 5, dynamic tunnel in 1, and chordae from left AV valve to LV outflow tract in 1. Thus, SAS in AV septal defect is most often due to a discrete anatomic lesion. Hemodynamic data show that SAS can be progressive, both before and after the surgical management of the AV septal defect.     

Bilateral ductus arteriosus (or remnant): an analysis of 27 patients

Bilateral ductus arteriosus (DA) was clinically recognized in 27 patients studied angiographically from 1963 through May 1983. Distal bilateral DA origin of non-confluent pulmonary arteries was identified in 15 patients, ectopic or distal ductal origin of 1 pulmonary artery in 9 patients (5 without evidence of intracardiac disease) and isolation of the left subclavian artery in 3 (all 3 of whom had a right aortic arch). Other conditions reported to be associated with bilateral DA include interruption of the aortic arch with isolation of a subclavian artery, aortic atresia with interruption of the aortic arch in which bilateral DA supports the entire systemic circulation, bilateral DA complicating forms of congenitally malformed hearts other than those just stated, and, rarely, bilateral DA in isolation. Understanding the symmetric or paired nature of the primitive aortic arch system in the developing human heart facilitates recognition of the patterns of fourth and sixth arch anomalies seen with bilateral DA.     

Risk for liver disease in adults with alpha1-antitrypsin deficiency

Risk for the development of liver disease was estimated in 115 adults with α₁-antitrypsin deficiency, most of whom were of PI type (protease inhibitor type) Z. Seventy-one subjects were ascertained through their disease; 44 were ascertained independently of disease. A low concentration of serum prealbumin was sensitive in detecting impaired liver function and may indicate functioning cell mass, a different parameter than is measured by liver enzymes.Liver disease has usually been considered rare in adults with α₁-antitrypsin deficiency. However, the risk for the development of liver disease was relatively high for men between 51 and 60 years of age. The risk for women was lower than that for men. Our study indicates that a periodic assessment of liver function may be warranted for patients with α₁-antitrypsin deficiency who are over 40 years of age.     

Residual hypertension after coarctectomy in children.

Coarctectomy in 190 children aged over 1 year to 15 years at operation produced a significant reduction in blood pressure for the group as a whole. Forty-nine patients (24 percent) remained hypertensive. Postoperative hypertension was unexplained in 29 (15 percent) of the 190 patients, and coarctation persisted or recurred in 20 (11 percent). For patients operated on between the ages of 4 and 15 years the earlier the age of operation, the greater the reduction in the blood pressure index: (measured blood pressure/normal mean systolic [or diastolic] blood pressure for age) X 100.     

Thallium-201 myocardial imaging in anomalous left coronary artery arising from the pulmonary artery: Applications before and after medical and surgical treatment

Thallium-201 myocardial imaging was performed on six patients with an anomalous left coronary artery arising from the pulmonary artery. Initial images in three children (aged 4 months, 12 months and $\text{2}\text{1}\text{2}\text{years}$, respectively) demonstrated anterolateral perfusion defects in agreement with the electrocardiographic localization of infarction. Repeat imaging in two patients 2 to 3 months later, after clinical improvement with anticongestive therapy, demonstrated a reduction in the perfusion defect. In 3 other patients (aged 16, 16 and 20 years, respectively) thallium-201 scans performed during exercise stress demonstrated normal myocardial perfusion 7 to 15 years after operation (ligation of anomalous left coronary in two, ligation plus bypass graft in one).Thallium-201 imaging appears to be helpful in monitoring changes in myocardial perfusion before and after medical or surgical treatment of an anomalous left coronary artery, and may shed light on the pathophysiology of the defect. A possible practical limitation of thallium-201 imaging in this condition is the difficulty of imaging subendocardial infarction.     

Survival after systemic to pulmonary arterial shunts in infants less than 30 days old with obstructive lesions of the right heart chambers.

Ninety-seven infants less than 30 days old with obstructive lesions of the right heart chambers underwent palliative surgery from 1950 through 1972. The diagnosis was made at cardiac catheterization and confirmed at operation or subsequent autopsy. Because of unavailability of complete preoperative studies and sufficient blood gas data, 36 patients presenting between 1950 and 1965 (Group I) were analyzed for surgical risk only. In 61 patients who underwent palliative procedures between 1966 and 1972 (Group II) a more detailed analysis was done. In this group, 31 had a Potts shunt, 29 a Waterston shunt and 1 a Blalock-Taussig shunt. The most frequently encountered malformation was severe tetralogy of Fallot (30 percent) with or without pulmonary atresia, followed by pulmonary atresia with intact ventricular septum (25 percent). The overall surgical mortality rate in patients seen after 1965 (Group II) was 34 percent compared with the 78 percent mortality rate in patients seen earlier (Group I). The surgical mortality in infants operated on during the 1st week of life was double that of those operated on in the 2nd through 4th weeks. Survivors were compared with nonsurvivors for timing of surgery, age at presentation and clinical profile. Only two significant differences were found. Preoperative continuous murmurs were more common in those who survived operation (13 of 40 patients) than in those who died (2 of 21). Arterial pH during cardiac catheterization was the best predictor of subsequent survival, nonsurvivors having significantly greater metabolic acidosis. Palliation of these severe lesions still carries a high mortality rate to which must be added the risk of subsequent repair. Our data suggest that primary repair is to be preferred if it can be undertaken with a risk approximating that of palliative procedures.     

Right ventricular ejection fraction and volumes after mustard repair: Correlation of two dimensional echocardiograms and cineangiograms

The right ventricular ejection fractions derived from two dimensional echocardiograms and cineangiograms were compared in 24 children. All patients (aged 2.1 to 16 years) had undergone Mustard repair for transposition of the great arteries 1 to 12 years earlier. The correlation of the two methods was excellent (r = 0.977), confirming the usefulness of echocardlography for deriving ejection fraction. The volume components of the ejection fraction were less well estimated from the echocardiograms, but the ratios of end-diastolic to end-systolic volumes estimated from each method were similar.     

Compression of intrapulmonary bronchi by abnormally branching pulmonary arteries associated with absent pulmonary valves

In 3 patients with absent pulmonary valve syndrome and absent ductus arteriosus, the lungs were injected and analyzed postmortem using morphometric techniques. Two patients had tetralogy of Fallot and 1 had D-transposition of the great arteries, the latter being the first autopsy-proved case of absent pulmonary valve with transposition. In addition to the expected dilatation of the central pulmonary arteries and compression of the mainstem bronchi, postmortem pulmonary arteriography revealed a bizarre pattern of hilar branching. Instead of single segmental arteries, tufts of arteries arose which entwined and compressed the intrapulmonary bronchi. In all 3 patients the histologic structure of the pulmonary arteries was abnormal. The elastic lamina of the media of the right and left pulmonary arteries were increased in number outside the lung, but were decreased within the lung. At both sites, the elastic laminae were thickened and fragmented. In the 2 ventilator-dependent patients, there was slight medial hypertrophy and extension of muscle into normally nonmuscular arteries. In 1 of the 2 cases in which the number of bronchial generations was counted, they were decreased, and in the 1 case in which bronchial count was unknown, alveolar multiplication was severely impaired. Therefore, our data may explain why, in some patients with absent pulmonary valve syndrome, relief of compression of the mainstem bronchi alone does not appreciably alleviate or reverse severe respiratory disease.     

Truncal or aortic valve stenosis in functionally single arterial trunk: A clinical,hemodynamic and pathologic study of six cases

Stenosis of the semilunar valve in the presence of a functionally single arterial trunk is uncommon. Three patients with truncus arteriosus, two with tetralogy of Fallot and pulmonary atresia and one with pulmonary atresia and intact septum were diagnosed as having stenosis of the truncal or aortic valve on the basis of clinical, echocardiographic, hemodynamic and angiocardiographic findings. Echocardiograms consistently showed multiple diastolic closure lines and abnormal semilunar valves in addition to the aortic override in five patients and hypoplastic right ventricle in the patient with pulmonary atresia and intact septum. Peak systolic gradients between the left ventricle and truncus (or aorta) at cardiac catheterization ranged from 20 to 47 mm Hg. Retrograde aortography confirmed a domed and stenotic semilunar valve. Cyanosis was progressive in the three patients with pulmonary atresia. Two patients had arterial anastomosis, and one had a right ventricle-pulmonary arterial graft in addition to aortic valvotomy. One of the three patients with truncus arteriosus underwent complete repair in addition to truncal valvotomy but he died in the postoperative period. The other two patients with truncus arteriosus died of intractable congestive cardiac failure before surgical intervention.It is suggested that the presence of semilunar valve stenosis in these patients adversely affects the prognosis. The myocardium is already jeopardized as a result of hypoxia in pulmonary atresia and left ventricular diastolic overload in patients with truncus arteriosus. The added burden of semilunar valve stenosis may further compromise the functional status of the myocardium.     

Ventricular septal defect and subaortic stenosis: An analysis of 41 patients

Forty-one patients with subaortic stenosis (SAS) and ventricular septal defect (VSD) were identified from the cardiac records of the Hospital for Sick Children, Toronto, Ontario. The diagnosis of an associated SAS was made clinically in only 1 patient, who had findings of left ventricular (LV) hypertrophy with strain on the electrocardiogram. There was a delay of 3.1 years between initial presentation and detection of SAS. The SAS was not diagnosed at initial catheterization in 17 patients and was confirmed at subsequent catheter studies in 8 patients, surgery in 5 and autopsy in 4. Associated defects included coarctation of the aorta in 12 patients, mitral valve abnormalities in 4, and right-sided obstructions, including anomalous right ventricular muscle bundles in 6 patients, tetralogy in 4 and pulmonic stenosis in 1 patient.

The mean gradient across the LV outflow tract was 25 mm Hg. Nineteen patients had serial catheters without intervening surgery, and the outflow gradient increased from a mean of 9 to 36 mm Hg. The mechanism of SAS consisted of fibrous diaphragm and fibromuscular obstruction in 31 cases, muscular narrowing in 4, protruding tricuspid valve leaflet in 2, hypertrophic cardiomyopathy in 2, anterolateral twist in 1 patient and redundant tissue tag in 1. Thirty-eight patients had a perimembranous VSD, 19 of whom had an associated so-called aneurysm of the membranous septum; 2 had an infundibular VSD and 1 patient had a central muscular defect. Although the SAS was located below the VSD in 30 cases, the associated heart failure and reduced cardiac output can mask the presence or severity of associated SAS. Cross-sectional echocardiography and axial angiography have greatly improved recognition of associated SAS.     

The criss-cross and superoinferior ventricular heart: an angiocardiographic study

The angiocardiographic features of 11 patients with superoinferior and criss-cross type of atrioventricular (A-V) connections are presented. These unusual ventricular relations are thought to result from postseptation disturbances of ventricular looping. The angiocardiographic appearance of criss-cross is really an illusion, and the A-V connections among these patients are either concordant, discordant or straddling. The often small right A-V valve inflow and sinus portion of the ventricle, combind with the ventricular rotational anomaly, combine to give the angiocardiographic perception of criss-cross. A review of the 11 patients from this institution and those previously reported on suggests that most patients have a transposition of malposition of the great arteries; many have a small right ventricle, and about half have pulmonary outflow tract obstruction. In addition to the obvious embryologic, morphologic and clinical implications of these distorted ventricular loops, the criss-cross A-V hearts raise questions about the various segmental nomenclatures applied to these types of congenital heart disease.     

Combined noninvasive assessment of the patent ductus arteriosus in the preterm infant before and after indomethacin treatment

Fifteen preterm infants who weighed 0.7 to 2.0 kg and had clinical evidence of a patent ductus arteriosus (PDA) were studied by combined 2-dimensional and Doppler echocardiography before and after the administration of indomethacin. In 10 patients the PDA was widely patent at the time of the study and in 5 the lumen was narrow. In this latter group, the PDA was narrow at the pulmonary artery end in 2 patients, in the middle in 2 patients and at the aortic end and the middle in 1 patient. After the administration of intravenous indomethacin, the PDA closed completely in 12 patients and constricted in 3. The patterns of closure could be documented in those in whom serial studies were performed. In 3 patients, closure occurred after a single dose of indomethacin, in 3 after 2 doses and in the rest after a full course of 3 doses. Doppler interrogation at the aortic and pulmonary artery end of the PDA demonstrated the shunting patterns and provided a reliable assessment of patency after the ductal lumen was outside the range of lateral resolution following constriction. In no case did the PDA reopen after the course of indomethacin. This combined approach is a reliable method of assessing a PDA before and after a course of indomethacin. It should provide the means to answer many of the questions regarding the effect of various manipulations on the PDA in the preterm infant.