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Tachypnea, tachycardia, cyanosis, and mediastinal mass in a neonate
CLINI CAL-P ATHO LOGI C AL C O N F E R E N C E * Jar Bernstein, Editor
Tachypnea, tachycardia, cyanosis, and mediastinal mass in a neonate W . M . T h o m p s o n , J r . , M . D . , O k l a h o m a City, Okla., a n d L. C l a r k e S t o u t , M . D . , * * Galveston, T e x a s
THE PATIENT was a 6-hour-old white male infant, who was transferred to Children's Memorial Hospital from another city. The gestation and delivery were said to have been unremarkable, although the umbilical cord was wrapped around the neck twice at delivery. The child was thought initially to have been in good condition, but respiratory difficulty became apparent shortly after birth. A roentgenogram of the chest showed a mass in the mediastinum, and the child was referred immediately to Children's Memorial Hospital. The mother and father were healthy, as was one sibling. The paternal great-grandfather had diabetes mellitus. Physical examination revealed the following: weight, 2,920 grams; respirations, 65 per minute; pulse, 195 per minute; temperature, 36.4 ~ C. The child was well developed, well nourished, and slightly cyanotic. The head and neck were normal. Inspection of the chest revealed mild intercostal and subcostal retractions. Auscultation revealed a decrease in breath sounds centrally and no r~les. The heart size could not be determined by physical examination. A grade 2 to 3 systolic murmur was heard over most of the chest, and there was a pronounced third heart sound. No diastolic murmur was audible. The peripheral arterial pulses were somewhat diminished, but were easily palpable in all extremities. The liver edge was felt 3 to 4 cm. below the right costal margin. It did not pulsate. No other abdominal organs were palpable. The neurologic examination was negative. From the Department of Pathology, University of Oklahoma Health Sciences Center. *Sponsored by the Pediatric Pathology Club. **Reprint address: Department of Pathology, University of Texas Medical Branch, Galveston, Texas 77550.
Laboratory data included the following: The hemoglobin concentration was 12.2 Gm. per 100 ml. and the hematocrit was 32 volumes per cent. The urine contained 3+ albumin and l + glucose; no cells were seen on microscopic examination. The blood urea nitrogen (BUN) was 15 mg. per 100 ml. The total serum bilirubin concentration was 11 mg. per 100 ml., with 6.4 mg. per 100 ml. in the conjugated fraction. A n electrocardiogram (ECG) showed a regular sinus r h y t h m with a mean QRS vector directed at +100 ~ The T vector was - 9 0 ~ to --100 ~ The chest leads showed an RS pattern over the right side with anteriorly directed T waves and a QR pattern at V 6. The tracing was thought to be consistent with left axis deviation and left ventricular hypertrophy. The P waves were suggestive of right atrial hypertrophy. A chest radiogram revealed marked enlargement of the cardiac silhouette. Lateral and oblique views with barium in the esophagus did not reveal any additional findings. Catheterization of the right side of the heart done on the evening of admission showed blood pressures in the range of 40 to 50 mm: Hg in the right ventricle and pulmonary artery. Angiograms with injections into the right atrium and pulmonary artery revealed a patent ductus arteriosus but no other right-sided abnormalities. There appeared to b e a bidirectional shunt through the ductus arteriosus, and the cardiac shadow was found to be much larger than the cardiac chamber size. Following catheterization the child appeared pale, and respirations ceased. A pericardiocentesis yielded bloody fluid. A thoracotomy was performed within an hour, and approximately 150 ml. of blood and blood clots were evacuated from the pericardial sac. Inspection of the heart revealed an enlarged left ventricle and normally positioned great vessels. The ascending aorta seemed some-
Vol. 84, No. 5, pp. 76~772
770
Thompson and Stout
The Journal of Pediatrics May 1974
Fig. 1. Anterior view of the opened left ventricle showing the stenotic aortic valve and focal fibrosis of the endocardial half of the myocardium.
w h a t small. N o o t h e r a b n o r m a l i t i e s were obvious, a n d t h e s o u r c e o f t h e pericardial b l o o d could n o t be determined.
The
patient
was
somewhat
improved
p o s t o p e r a t i v e l y , but h e required c o n t i n u o u s c o n t r o l l e d r e s p i r a t o r y s u p p o r t a n d had i n t e r m i t t e n t e p i s o d e s o f bradycardia. T h e child c o n t i n u e d to do poorly o n t h e following day, w h e n t h e blood p H was 7.00, P c o 2 58, a n d P o 2 19. T h e child's c o n d i t i o n r e m a i n e d precarious, a n d h e died at t h e age o f 42 hours. DISCUSSION DR. W. M. THOMPSON,JR. This infant had a very early onset of difficulties. Although we are given a history of the cord having been wrapped around the neck twice, there were no observed signs of fetal distress. His initial condition was good, but within a short time he developed respiratory distress, the details of which are not given. A chest radiograph obtained in :the local hospital revealed a mediastinal mass. The most common mediastinal mass is, of course, the heart. Respiratory distress is common in neonates, and in spite of many opinions to the contrary, cardiac abnormalities constitute a relatively infrequent cause. A study of a number of neonates referred to a children's hospital in England because of cyanosis showed that cardiac causes of respiratory distress were a relatively poor third. Central nervous system disease and primary pulmonary abnormalities were considerably more common. 1 Thus, statistically, the odds are against a cardiac disease being the cause of the respiratory distress in the present child. The child was cyanotic at 6 hours at age. We are not told about differing areas of cyanosis, obviously an important part of the
physical examination in any cyanotic infant. The remainder of the physical examination revealed a systolic heart murmur possibly decreased amplitude of all peripheral pulses, and an enlarged liver. May we see the radiographs now? DR. JEAN VANHOUTTE,The radiograph of the chest t~ken on admission showed that the mediastinal mass was indeed heart, as Dr. Thompson suggested. The cardiac shadow fills 90 per cent of the chest. Lateral and oblique views with barium in the esophagus revealed no additional findings. I cannot exclude the possibility of a pericardial effusion. DR. THOMPSON. Despite statistical evidence to the contrary, most data point to the cardiovascular system as the cause of respiratory distress in this child. The combination of respiratory distress, cyanosis, cardiomegaly, tachycardia, and hepatomegaly suggests congestive heart failure. In general, a limited number of entities will cause congestive heart failure at this age. Although congestive heart failure usually points to some congenital anomaly of the heart, we must consider other vascular abnormalities, such as intracranial arteriovenous malformations. However, we have no evidence to suggest a lesion associated with high stroke volume. The major causes of congestive heart failure during the first week of life are the hypoplastic left heart syndromes, the hypoplastic right heart syndromes, transposition of the great vessels, and coarctation of the aorta. Other miscellaneous conditions include total anomalous pulmonary venous drainage, severe valvular obstruction, and myocardial malfunction. Myocardial malfunction may be due to viral myocarditis. The prognosis is poor in all patients who develop congestive heart failure during the first week of life. Approximately 85 per cent are dead within less than one month. The prognosis improves somewhat with later onset of congestive failure, but remains poor. Because of this, aggressive diagnostic efforts, including cardiac catheterization and angiography, are indicated. May we see the angiograms? DR. DAVID EAKIN.The right atrial and pulmonary artery injections showed a patent ductus arteriosus and relatively normal right atrium, right ventricle, and pulmonary arteries. A marked discrepancy was seen between the chamber size and the over-all cardiac size, however, indicating the presence of a significant pericardial effusion. Chest radiographs taken postoperatively showed a marked decrease in heart size with downward and outward displacement of the apex, suggesting left ventricular enlargement or dilatation. DR. THOMPSON.These studies are quite helpful, since I would have expected to find one of the hypoplastic right heart syndromes in a neonate presenting with cyanosis, cardiomegaly, congestive heart failure, and ECG evidence of left ventricular hypertrophy. Because of progressive deterioration, a pericardiocentesis was done with withdrawal of bloody fluid. The response to this procedure was less than dramatic, and the patient was taken to the operating room, where 150 ml. of serosanguineous fluid and blood clot were removed from the pericardial sac. No great improvement resulted, and shortly thereafter the child died. Therefore, we must postulate that additional significant cardiac disease was present.
Volume 84 Number 5
Tachypnea, tachycardia, cyanosis, and mediastinal mass
771
Fig. 2. Microscopic section showing extensive fibrosis of the endocardial half of the left ventricle with focal calcification and endocardial thickening. (Masson's trichrome stain; •
I would like to consider first the causes of hemopericardium, which is r/ot a common abnormality in the neonate. Trauma must be considered, particularly following efforts at resuscitation. We have no history to suggest trauma in this child, since the delivery was described as easy and there were no aggressive efforts at resuscitation. There was nothing about the catheterization to indicate perforation of the myocardium, and the pericardial effusion was present prior to any intracardiac manipulation. Bacterial or viral pericarditis might conceivably lead to hemopericardium, but purulent material should have been found along with the blood. Rheumatic fever is the ,most common cause of pericarditis in childhood, but I have never seen rheumatic fever at this age. Pericardial teratomas with bloody effusions may occur in neonates, but this diagnosis would have been obvious at surgery. The accumulation of bloody pericardial effusion with myocardial infarction is certainly not rare in adults, especially those who receive anticoagulants. Myocardial infarction has been reported in neonates,2 but in the case cited it occurred after birth and was due to embolization from the ductus venosus. The large size of the effusion in our infant indicated that it must have formed in utero, probably over a period of several weeks. I do believe that the hemopericardium was large enough to explain the child's anemia and unconjugated hyperbilirubinemia. The conjugated hyperbilirubinemia was presumably due to passive congestion of the liver. Unfortunately, I cannot adequately explain the hemopericardium. As to the cause of the child's enlarged left ventricle, systolic murmur, left ventricular hypertrophy suggested by the ECG, cyanosis, and large heart, structural abnormalities to be considered would include hypoplastic right heart syndrome, severe aortic stenosis, and coarctation of the aorta. The hypoplastic right heart syndrome is clearly ruled out by the angiogram. Peripheral pulses in the extremities certainly can occur with
coarctation of the aorta, particularly with a predominant rightto-left shunt through the ductus arteriosus into the descending aorta, which was indeed demonstrated angiographically. However, if this were the case, differential cyanosis should have been obvious. At any rate, coai'ctation of the aorta was ruled out at operation, leaving me with the diagnosis of aortic stenosis. Aortic stenosis sufficiently severe to cause cardiac failure at this age does occur. It is not particularly common; statistically, aortic coarctation would be much more likely. Incidentally, the angiogram very clearly rules out the second most common cause of failure, D-loop transposition, since the pulmonary artery is in its normal position.
Dr. Thompson's diagnoses: C o n g e n i t a l aortic s t e n o s i s H e m o p e r i c a r d i u m , etiology u n k n o w n QUESTION. Dr. Thompson, why did you think that the hemopericardium developed in utero? DR. THOMPSON.The pericardial sac is relatively inelastic, and I would guess that it would take several weeks to dilate from a normal volume of less than 10 ml. to the volume of 150 ml. observed in this patient. PATHOLOGICAL
FINDINGS
DR. CLARKE STOUT. At postmortem examination, the left ventricle was markedly enlarged, being two to three times normal size. The only congenital anomaly present was valvular aortic stenosis. The valve orifice was approximately 0.2 cm. in diameter. The valve was unicommissural without recognizable cusps (Fig. 1). I suppose that some regurgitation could have been present, although this is difficult to assess at autopsy. The left ventricle was both hypertrophied and dilated and there was focal endocardial fibroelastosis. Many areas of fibrosis
772
Thompson and Stout
were found throughout the left ventricular myocardium. The fibrosis was most prominent in the endocardial portion of the muscle, but in some areas extended to the epicardial surface. Histologically, much of the fibrous tissue was well collagenized, indicating a duration of at least four weeks (Fig. 2). Collections of hemosiderin-laden macrophages suggesting previous hemorrhage were found in the epicardial tissue adjacent to areas of fibrosis. No gross lesions were visible on the epicardial surface of the heart or on the visceral surface of the pericardial sac. Therefore, I think that the hemorrhagic pericardial effusion probably resulted from seepage of blood from the infarcted left ventricle several weeks prior to birth. There were multiple areas of acute necrosis scattered throughout the left ventricle. These areas were also concentrated in the inner portion of the myocardium. Histologically, only a few neutrophils were present in the areas of acute necrosis, indicating a duration of 12 to 24 hours. The acute necrosis was possibly due to low perfusion related to the combination of cardiac tamponade, aortic stenosis, and tachycardia. I suspect that the myocardial fibrosis was also due to ischemia resulting from aortic stenosis and myocardial hypertrophy. The epicardial and intramural coronary arteries were normal. QUESTION.IS it possible to make a clinical diagnosis of aortic stenosis at this age, and if it were detected, would a corrective or palliative operation be indicated? DR. G. RAINEY WILLIAMS.Aortic stenosis could be detected with a left ventricular injection. The question of whether or not it could be repaired is more difficult to answer. The youngest child with aortic stenosis undergoing surgery that I can personally remember was one or two months of age. It was possible, under inflow occlusion, to open the aorta and then open the valve with survival of the child. However, I doubt if the valve in the present patient could have been opened without causing incompetence, and acute aortic valvular insufficiency is a pretty disabling hemodynamic problem. In general, the artificial valves available today are small enough to be put in children 8 to 10 years old. However, their structure is such that there is considerable obstruction to central flow and most people feel that this is one situation where a homograft is preferable because its flow characteristics are so much better. QUESTION.Could aortic stenosis really reduce coronary blood flow sufficiently to produce this much fibrosis? DR. STOUT. I think that this explanation is reasonable. Papillary muscle infarction has been noted in association with:aortic stenosis without coronary arterial occlusion.3 Perhaps Dr. Thompson could speak to this point. DR.THOMPSON.In general, coronary blood flow is decreased in patients with aortic stenosis of almost any degree. The intramural pressure in patients with aortic stenosis may exceed the perfusion pressure available from the aorta during systole by
The Journal of Pediatrics May 1974
a factor of two- to threefold, so blood may be squeezed out of the coronary arteries during systolic contraction. Also, most data indicate that with hypertrophy the muscle bundles grow out of close contact with their capillaries, thus reducing their oxygen supply, Patients with aortic stenosis tolerate tachycardia poorly since tachycardia is associated with a shortened diastolic time, and this is the period of major coronary blood flow. These problems are all compounded by anything which reduces cardiac output, such as myocardial fibrosis and pericardial tamponade. QUESTION.Dr. Stout, you mentioned fibroelastosis of the left ventricle. Did this child have the entity known as congenital fibroelastosis? DR. STOtYr. No. The fibroelastosis was seen only overlying areas of myocardial fibrosis. QUESTION,I would like to ask Dr. Thompson to comment on the large left ventricular chamber. Don't most patients with congenital aortic stenosis have small or normal-sized left ventricular chambers at the time of birth? DR. THOMPSON.The predominant flow into the left ventricle during fetal life occurs across the foramen ovale from the right side. With severe aortic obstruction, there is a rise in the enddiastolic pressure in the left ventricle which leads to an increase in pressure i n the left atrium until it exceeds that in the right atrium, thus obliterating the majority of blood flow into the left ventricle. Therefore, the usual situation at birth with severe congenital aortic stenosis is a small, thick-walled, but actually hypoplastic left ventricle. The left ventricular chamber usually becomes dilated only after the onset of congestive failure in older children and adults. I suppose that the dilatation in the present case could be explained on this basis, that is, the ischemic necrosis and fibrosis weakened the left ventricle sufficiently to cause failure and dilatation. Also, there may have been some aortic regurgitation, which could have produced enlargement of the ventricular cavity.
Final pathological diagnoses: C o n g e n i t a l aortic s t e n o s i s E x t e n s i v e areas o f old a n d r e c e n t infarction o f left ventricle, apparently i s c h e m i c in origin H e m o p e r i c a r d i u m , a p p a r e n t l y due to s e e p a g e f r o m m y o c a r d i a l infarcts
REFERENCES 1. Craig, W. S.: Admissions and readmissions from district to the special baby-care unit of a maternity hospital, Br. Med. J. 2: 1139, 1962. 2. Berry, C. L.: Myocardial infarction in a neonate, Br. Heart J. 32: 412, 1970. 3. Gould, S. E., editor: Pathology of the heart and blood vessels, Springfield, II1., 1968, Charles C Thomas, Publisher, p. 336.
Tachypnea, tachycardia, cyanosis, and mediastinal mass in a neonate W . M . T h o m p s o n , J r . , M . D . , O k l a h o m a City, Okla., a n d L. C l a r k e S t o u t , M . D . , * * Galveston, T e x a s
THE PATIENT was a 6-hour-old white male infant, who was transferred to Children's Memorial Hospital from another city. The gestation and delivery were said to have been unremarkable, although the umbilical cord was wrapped around the neck twice at delivery. The child was thought initially to have been in good condition, but respiratory difficulty became apparent shortly after birth. A roentgenogram of the chest showed a mass in the mediastinum, and the child was referred immediately to Children's Memorial Hospital. The mother and father were healthy, as was one sibling. The paternal great-grandfather had diabetes mellitus. Physical examination revealed the following: weight, 2,920 grams; respirations, 65 per minute; pulse, 195 per minute; temperature, 36.4 ~ C. The child was well developed, well nourished, and slightly cyanotic. The head and neck were normal. Inspection of the chest revealed mild intercostal and subcostal retractions. Auscultation revealed a decrease in breath sounds centrally and no r~les. The heart size could not be determined by physical examination. A grade 2 to 3 systolic murmur was heard over most of the chest, and there was a pronounced third heart sound. No diastolic murmur was audible. The peripheral arterial pulses were somewhat diminished, but were easily palpable in all extremities. The liver edge was felt 3 to 4 cm. below the right costal margin. It did not pulsate. No other abdominal organs were palpable. The neurologic examination was negative. From the Department of Pathology, University of Oklahoma Health Sciences Center. *Sponsored by the Pediatric Pathology Club. **Reprint address: Department of Pathology, University of Texas Medical Branch, Galveston, Texas 77550.
Laboratory data included the following: The hemoglobin concentration was 12.2 Gm. per 100 ml. and the hematocrit was 32 volumes per cent. The urine contained 3+ albumin and l + glucose; no cells were seen on microscopic examination. The blood urea nitrogen (BUN) was 15 mg. per 100 ml. The total serum bilirubin concentration was 11 mg. per 100 ml., with 6.4 mg. per 100 ml. in the conjugated fraction. A n electrocardiogram (ECG) showed a regular sinus r h y t h m with a mean QRS vector directed at +100 ~ The T vector was - 9 0 ~ to --100 ~ The chest leads showed an RS pattern over the right side with anteriorly directed T waves and a QR pattern at V 6. The tracing was thought to be consistent with left axis deviation and left ventricular hypertrophy. The P waves were suggestive of right atrial hypertrophy. A chest radiogram revealed marked enlargement of the cardiac silhouette. Lateral and oblique views with barium in the esophagus did not reveal any additional findings. Catheterization of the right side of the heart done on the evening of admission showed blood pressures in the range of 40 to 50 mm: Hg in the right ventricle and pulmonary artery. Angiograms with injections into the right atrium and pulmonary artery revealed a patent ductus arteriosus but no other right-sided abnormalities. There appeared to b e a bidirectional shunt through the ductus arteriosus, and the cardiac shadow was found to be much larger than the cardiac chamber size. Following catheterization the child appeared pale, and respirations ceased. A pericardiocentesis yielded bloody fluid. A thoracotomy was performed within an hour, and approximately 150 ml. of blood and blood clots were evacuated from the pericardial sac. Inspection of the heart revealed an enlarged left ventricle and normally positioned great vessels. The ascending aorta seemed some-
Vol. 84, No. 5, pp. 76~772
770
Thompson and Stout
The Journal of Pediatrics May 1974
Fig. 1. Anterior view of the opened left ventricle showing the stenotic aortic valve and focal fibrosis of the endocardial half of the myocardium.
w h a t small. N o o t h e r a b n o r m a l i t i e s were obvious, a n d t h e s o u r c e o f t h e pericardial b l o o d could n o t be determined.
The
patient
was
somewhat
improved
p o s t o p e r a t i v e l y , but h e required c o n t i n u o u s c o n t r o l l e d r e s p i r a t o r y s u p p o r t a n d had i n t e r m i t t e n t e p i s o d e s o f bradycardia. T h e child c o n t i n u e d to do poorly o n t h e following day, w h e n t h e blood p H was 7.00, P c o 2 58, a n d P o 2 19. T h e child's c o n d i t i o n r e m a i n e d precarious, a n d h e died at t h e age o f 42 hours. DISCUSSION DR. W. M. THOMPSON,JR. This infant had a very early onset of difficulties. Although we are given a history of the cord having been wrapped around the neck twice, there were no observed signs of fetal distress. His initial condition was good, but within a short time he developed respiratory distress, the details of which are not given. A chest radiograph obtained in :the local hospital revealed a mediastinal mass. The most common mediastinal mass is, of course, the heart. Respiratory distress is common in neonates, and in spite of many opinions to the contrary, cardiac abnormalities constitute a relatively infrequent cause. A study of a number of neonates referred to a children's hospital in England because of cyanosis showed that cardiac causes of respiratory distress were a relatively poor third. Central nervous system disease and primary pulmonary abnormalities were considerably more common. 1 Thus, statistically, the odds are against a cardiac disease being the cause of the respiratory distress in the present child. The child was cyanotic at 6 hours at age. We are not told about differing areas of cyanosis, obviously an important part of the
physical examination in any cyanotic infant. The remainder of the physical examination revealed a systolic heart murmur possibly decreased amplitude of all peripheral pulses, and an enlarged liver. May we see the radiographs now? DR. JEAN VANHOUTTE,The radiograph of the chest t~ken on admission showed that the mediastinal mass was indeed heart, as Dr. Thompson suggested. The cardiac shadow fills 90 per cent of the chest. Lateral and oblique views with barium in the esophagus revealed no additional findings. I cannot exclude the possibility of a pericardial effusion. DR. THOMPSON. Despite statistical evidence to the contrary, most data point to the cardiovascular system as the cause of respiratory distress in this child. The combination of respiratory distress, cyanosis, cardiomegaly, tachycardia, and hepatomegaly suggests congestive heart failure. In general, a limited number of entities will cause congestive heart failure at this age. Although congestive heart failure usually points to some congenital anomaly of the heart, we must consider other vascular abnormalities, such as intracranial arteriovenous malformations. However, we have no evidence to suggest a lesion associated with high stroke volume. The major causes of congestive heart failure during the first week of life are the hypoplastic left heart syndromes, the hypoplastic right heart syndromes, transposition of the great vessels, and coarctation of the aorta. Other miscellaneous conditions include total anomalous pulmonary venous drainage, severe valvular obstruction, and myocardial malfunction. Myocardial malfunction may be due to viral myocarditis. The prognosis is poor in all patients who develop congestive heart failure during the first week of life. Approximately 85 per cent are dead within less than one month. The prognosis improves somewhat with later onset of congestive failure, but remains poor. Because of this, aggressive diagnostic efforts, including cardiac catheterization and angiography, are indicated. May we see the angiograms? DR. DAVID EAKIN.The right atrial and pulmonary artery injections showed a patent ductus arteriosus and relatively normal right atrium, right ventricle, and pulmonary arteries. A marked discrepancy was seen between the chamber size and the over-all cardiac size, however, indicating the presence of a significant pericardial effusion. Chest radiographs taken postoperatively showed a marked decrease in heart size with downward and outward displacement of the apex, suggesting left ventricular enlargement or dilatation. DR. THOMPSON.These studies are quite helpful, since I would have expected to find one of the hypoplastic right heart syndromes in a neonate presenting with cyanosis, cardiomegaly, congestive heart failure, and ECG evidence of left ventricular hypertrophy. Because of progressive deterioration, a pericardiocentesis was done with withdrawal of bloody fluid. The response to this procedure was less than dramatic, and the patient was taken to the operating room, where 150 ml. of serosanguineous fluid and blood clot were removed from the pericardial sac. No great improvement resulted, and shortly thereafter the child died. Therefore, we must postulate that additional significant cardiac disease was present.
Volume 84 Number 5
Tachypnea, tachycardia, cyanosis, and mediastinal mass
771
Fig. 2. Microscopic section showing extensive fibrosis of the endocardial half of the left ventricle with focal calcification and endocardial thickening. (Masson's trichrome stain; •
I would like to consider first the causes of hemopericardium, which is r/ot a common abnormality in the neonate. Trauma must be considered, particularly following efforts at resuscitation. We have no history to suggest trauma in this child, since the delivery was described as easy and there were no aggressive efforts at resuscitation. There was nothing about the catheterization to indicate perforation of the myocardium, and the pericardial effusion was present prior to any intracardiac manipulation. Bacterial or viral pericarditis might conceivably lead to hemopericardium, but purulent material should have been found along with the blood. Rheumatic fever is the ,most common cause of pericarditis in childhood, but I have never seen rheumatic fever at this age. Pericardial teratomas with bloody effusions may occur in neonates, but this diagnosis would have been obvious at surgery. The accumulation of bloody pericardial effusion with myocardial infarction is certainly not rare in adults, especially those who receive anticoagulants. Myocardial infarction has been reported in neonates,2 but in the case cited it occurred after birth and was due to embolization from the ductus venosus. The large size of the effusion in our infant indicated that it must have formed in utero, probably over a period of several weeks. I do believe that the hemopericardium was large enough to explain the child's anemia and unconjugated hyperbilirubinemia. The conjugated hyperbilirubinemia was presumably due to passive congestion of the liver. Unfortunately, I cannot adequately explain the hemopericardium. As to the cause of the child's enlarged left ventricle, systolic murmur, left ventricular hypertrophy suggested by the ECG, cyanosis, and large heart, structural abnormalities to be considered would include hypoplastic right heart syndrome, severe aortic stenosis, and coarctation of the aorta. The hypoplastic right heart syndrome is clearly ruled out by the angiogram. Peripheral pulses in the extremities certainly can occur with
coarctation of the aorta, particularly with a predominant rightto-left shunt through the ductus arteriosus into the descending aorta, which was indeed demonstrated angiographically. However, if this were the case, differential cyanosis should have been obvious. At any rate, coai'ctation of the aorta was ruled out at operation, leaving me with the diagnosis of aortic stenosis. Aortic stenosis sufficiently severe to cause cardiac failure at this age does occur. It is not particularly common; statistically, aortic coarctation would be much more likely. Incidentally, the angiogram very clearly rules out the second most common cause of failure, D-loop transposition, since the pulmonary artery is in its normal position.
Dr. Thompson's diagnoses: C o n g e n i t a l aortic s t e n o s i s H e m o p e r i c a r d i u m , etiology u n k n o w n QUESTION. Dr. Thompson, why did you think that the hemopericardium developed in utero? DR. THOMPSON.The pericardial sac is relatively inelastic, and I would guess that it would take several weeks to dilate from a normal volume of less than 10 ml. to the volume of 150 ml. observed in this patient. PATHOLOGICAL
FINDINGS
DR. CLARKE STOUT. At postmortem examination, the left ventricle was markedly enlarged, being two to three times normal size. The only congenital anomaly present was valvular aortic stenosis. The valve orifice was approximately 0.2 cm. in diameter. The valve was unicommissural without recognizable cusps (Fig. 1). I suppose that some regurgitation could have been present, although this is difficult to assess at autopsy. The left ventricle was both hypertrophied and dilated and there was focal endocardial fibroelastosis. Many areas of fibrosis
772
Thompson and Stout
were found throughout the left ventricular myocardium. The fibrosis was most prominent in the endocardial portion of the muscle, but in some areas extended to the epicardial surface. Histologically, much of the fibrous tissue was well collagenized, indicating a duration of at least four weeks (Fig. 2). Collections of hemosiderin-laden macrophages suggesting previous hemorrhage were found in the epicardial tissue adjacent to areas of fibrosis. No gross lesions were visible on the epicardial surface of the heart or on the visceral surface of the pericardial sac. Therefore, I think that the hemorrhagic pericardial effusion probably resulted from seepage of blood from the infarcted left ventricle several weeks prior to birth. There were multiple areas of acute necrosis scattered throughout the left ventricle. These areas were also concentrated in the inner portion of the myocardium. Histologically, only a few neutrophils were present in the areas of acute necrosis, indicating a duration of 12 to 24 hours. The acute necrosis was possibly due to low perfusion related to the combination of cardiac tamponade, aortic stenosis, and tachycardia. I suspect that the myocardial fibrosis was also due to ischemia resulting from aortic stenosis and myocardial hypertrophy. The epicardial and intramural coronary arteries were normal. QUESTION.IS it possible to make a clinical diagnosis of aortic stenosis at this age, and if it were detected, would a corrective or palliative operation be indicated? DR. G. RAINEY WILLIAMS.Aortic stenosis could be detected with a left ventricular injection. The question of whether or not it could be repaired is more difficult to answer. The youngest child with aortic stenosis undergoing surgery that I can personally remember was one or two months of age. It was possible, under inflow occlusion, to open the aorta and then open the valve with survival of the child. However, I doubt if the valve in the present patient could have been opened without causing incompetence, and acute aortic valvular insufficiency is a pretty disabling hemodynamic problem. In general, the artificial valves available today are small enough to be put in children 8 to 10 years old. However, their structure is such that there is considerable obstruction to central flow and most people feel that this is one situation where a homograft is preferable because its flow characteristics are so much better. QUESTION.Could aortic stenosis really reduce coronary blood flow sufficiently to produce this much fibrosis? DR. STOUT. I think that this explanation is reasonable. Papillary muscle infarction has been noted in association with:aortic stenosis without coronary arterial occlusion.3 Perhaps Dr. Thompson could speak to this point. DR.THOMPSON.In general, coronary blood flow is decreased in patients with aortic stenosis of almost any degree. The intramural pressure in patients with aortic stenosis may exceed the perfusion pressure available from the aorta during systole by
The Journal of Pediatrics May 1974
a factor of two- to threefold, so blood may be squeezed out of the coronary arteries during systolic contraction. Also, most data indicate that with hypertrophy the muscle bundles grow out of close contact with their capillaries, thus reducing their oxygen supply, Patients with aortic stenosis tolerate tachycardia poorly since tachycardia is associated with a shortened diastolic time, and this is the period of major coronary blood flow. These problems are all compounded by anything which reduces cardiac output, such as myocardial fibrosis and pericardial tamponade. QUESTION.Dr. Stout, you mentioned fibroelastosis of the left ventricle. Did this child have the entity known as congenital fibroelastosis? DR. STOtYr. No. The fibroelastosis was seen only overlying areas of myocardial fibrosis. QUESTION,I would like to ask Dr. Thompson to comment on the large left ventricular chamber. Don't most patients with congenital aortic stenosis have small or normal-sized left ventricular chambers at the time of birth? DR. THOMPSON.The predominant flow into the left ventricle during fetal life occurs across the foramen ovale from the right side. With severe aortic obstruction, there is a rise in the enddiastolic pressure in the left ventricle which leads to an increase in pressure i n the left atrium until it exceeds that in the right atrium, thus obliterating the majority of blood flow into the left ventricle. Therefore, the usual situation at birth with severe congenital aortic stenosis is a small, thick-walled, but actually hypoplastic left ventricle. The left ventricular chamber usually becomes dilated only after the onset of congestive failure in older children and adults. I suppose that the dilatation in the present case could be explained on this basis, that is, the ischemic necrosis and fibrosis weakened the left ventricle sufficiently to cause failure and dilatation. Also, there may have been some aortic regurgitation, which could have produced enlargement of the ventricular cavity.
Final pathological diagnoses: C o n g e n i t a l aortic s t e n o s i s E x t e n s i v e areas o f old a n d r e c e n t infarction o f left ventricle, apparently i s c h e m i c in origin H e m o p e r i c a r d i u m , a p p a r e n t l y due to s e e p a g e f r o m m y o c a r d i a l infarcts
REFERENCES 1. Craig, W. S.: Admissions and readmissions from district to the special baby-care unit of a maternity hospital, Br. Med. J. 2: 1139, 1962. 2. Berry, C. L.: Myocardial infarction in a neonate, Br. Heart J. 32: 412, 1970. 3. Gould, S. E., editor: Pathology of the heart and blood vessels, Springfield, II1., 1968, Charles C Thomas, Publisher, p. 336.