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To assess the etiology of depressed ventricular function in cyanotic congenital heart disease, an experimental model in immature puppies was devised in which the left atrial appendage is directly anastamosed to the distally banded pulmonary artery. The preparation results in significant cyanosis during a 3-month study period (PO2 = 91 +/- 4 vs 43 +/- 3, hematocrit = 33 +/- 3 vs 55 +/- 5). Compared to age- and weight-matched unoperated controls, cyanotic animals developed significant depression of biventricular ejection fraction (P less than 0.05), increased heart weight indexed for body weight (P less than 0.05), increased right ventricular weight (P less than 0.02), and increased right ventricular free wall thickness (P less than 0.05). There was no alteration in ventricular volumes. In addition, mean myocardial stores of high-energy phosphate compounds were unaltered. The model allows a reproducible level of hypoxemia to be produced in young animals, utilizes no prosthetic materials, and allows future experiments to be performed to ascertain the metabolic response of the cyanotic myocardium to exercise or surgically induced ischemia.

A new rat allograft model has been investigated for its potential to facilitate organ transplantation. In this procedure heart and spleen of male inbred LEW rat (RT1') were connected to the main abdominal vessels in inbred ACI rat (RT1a). With optimal surgical technique we obtain 64% permanent graft survival (5-14 months) in the splenectomized recipients. Cardiac histology ranged from preserved myocardium with moderate thickening of coronary artery walls to diffuse myocardial fibrosis with marked involutional changes of coronary arteries. Whereas palpation and EKG wrongly indicate good function beyond the fourth month, only the phonocardiogram shows the rapid functional loss which reflects the true morphologic involution.

Use of computerized tomography (CT) in the diagnosis of arterial calcification of infancy, including coronary obstructive disease, has not been previously reported. We were able to demonstrate by CT scan the abnormal arteries present in this disease. The calcified arteries in this infant, who died of bowel infarction at three weeks of age, were easily delineated in CT scans of the chest, abdomen, and extremities. Autopsy sections revealed intact elastic fibers in the abnormal arteries, indicating that the basic pathologic process does not primarily involve these fibers.

Sudden death during sleep has occurred among previously healthy Southeast Asian male refugees, but routine autopsies have not determined the cause of death in any of these cases. We report the first systematic attempt to define the cardiac abnormalities associated with this syndrome. Among 18 hearts examined, 14 showed slight to significant cardiomegaly, characteristic of increased cardiac work load. The reasons for the cardiomegaly remain unexplained. Conduction system anomalies were present in all but one heart. These included persistent fetal dispersion of the atrioventricular node and/or bundle of His, present in 14 hearts; accessory conduction fiber connections, found in 13 cases; and congenital heart block, observed in one case. These abnormalities were associated with variations in the structure of the cardiac base, suggesting a common aberrant developmental process. Although the functional significance of these findings has not been established, the conduction system anomalies may be the substrate for sleep-related cardiac arrhythmias and sudden death.

Standard autopsy specimens from 49 infants and children, most with congenital heart disease, were prepared by controlled pressure coronary artery perfusion fixation of the heart. Autopsy measurements of tricuspid (TV) and pulmonary valve (PV) circumferences (Circ), right ventricular (RV) outflow circumference, (Circ), RV inflow and outflow tract lengths, and RV volume (Vol) were correlated with corresponding in vivo end-diastolic (D) and end-systolic (S) measurements from biplane cineangiograms (angio) in the same patients. Correlation of the dimensions studied yielded the following r values: TV 0.72, PV 0.78, D Circ 0.61, S Circ 0.56, D inflow spatial (sp) 0.83, S inflow sp 0.83, D outflow sp 0.87, S outflow sp 0.84, D Vol 0.80, and S Vol 0.80. Mean angio and autopsy values were not significantly different for spatial outflow tract measurments and S Vol. Average autopsy values were lower than all other D angio measurements: (p [diff] < 0.001) and S inflow sp, (p [diff] < 0.05), but higher than all other S angio measurements, (p [diff] < 0.05-0.001). The data show the predictability of the changes in RV morphology with this fixation method and provide a basis for meaningful comparison of quantitative autopsy and angio dimensions of the RV.

Detailed autopsy measurements were performed in 13 infants with hypoplastic left ventricle and aortic atresia. Emphasis was placed on the evaluation of changes in the right ventricle, since its function may be important in determining surgical survival. Other important aspects were the ascending aortic and transverse aortic arch diameter, the presence of left atrial obstruction, and the size of the left atrium. The development of improved 2DE and Doppler imaging will permit preoperative and sequential evaluation of these parameters. Measurements performed in this study may serve as a basis for selection of infants for palliative surgery; these procedures are being undertaken more frequently in this hitherto fatal lesion. The measurements may also serve as a basis for noninvasive serial studies of these infants postoperatively.

Sudden cardiac death can be caused by a large variety of pathological conditions detected morphologically. In most cases it is the result of coronary sclerosis. A coronary thrombus is not only found in myocardial infarction, but also frequently occurs in unstable angina without infarction. In most instances these thrombi develop following rupture of an atheromatous plaque. A higher risk of sudden cardiac death is associated with abnormalities of the coronary ostia, most commonly an anomalous origin of the left coronary artery from the right sinus. HOCM is the most important cardiomyopathy causing sudden cardiac death in young athletes. Furthermore, myocarditis, pathological changes of the conduction system, and other rare conditions can lead to sudden cardiac death. A particular set of diseases contributes to sudden cardiac death in the young. Occasionally, disturbances in the texture of the ventricular septum can be found that have so far not been described in the literature. Acute arrhythmias hold a key position among the pathophysiological mechanisms leading to sudden cardiac death.

To evaluate controlled pressure coronary artery perfusion fixation of hearts as a means of obtaining meaningful cardiac measurements at autopsy, left ventricular (LV) autopsy measurements were correlated with in vivo end-diastolic (D) and end-systolic (S) angiographic (angio) values from biplane cineangiograms in the same patients. Mitral (MV) and aortic valve (AV) circumferences, LV equatorial circumference (Circ), spatial inflow and outflow lengths, wall thickness (W) and LV volume (Vol) were measured in 34 children with congenital heart disease. All dimensions showed significant correlation of angiographic and autopsy data from which linear regression equations were derived. The r values obtained were: MV 0.74; AV 0.85; D Circ 0.83; S Circ 0.82; D inflow 0.92; S inflow 0.90; D and S outflow 0.96; W 0.78; D Vol 0.92; S Vol 0.86. Mean angio and autopsy values were not significantly different for AV, S inflow, and S Vol. Autopsy values were lower than all D angio values and MV (P less than 0.001 for all), and higher than angio W and S outflow (P less than 0.001 for both). The data show that changes of LV morphology with this fixation method are predictable, making estimation of in vivo values from autopsy measurements possible using the derived linear regression equations.

In an infant with aortic atresia, two surgical procedures resulted in a 45 day postoperative survival. An atrial septectomy was initially performed. This was followed by the insertion of a Dacron graft from the main pulmonary artery to the descending thoracic aorta; the pulmonary artery was handed distal to the graft and the ductus arteriosus was ligated. Prostaglandin E1 was infused from the time of the diagnostic study to the second surgical procedure, 48 hours later. A postoperative cardiac catheterization was performed 3 weeks following the operation. Death occurred at 67 days of age from renal failure and a low cardiac output state.