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To evaluate the effect of volume loading in the low output state associated with right ventricular infarction, isolated right ventricular infarction was produced in seven dogs with the pericardium intact. Volume loading and pericardiotomy were then sequentially performed. After the production of right ventricular infarction, right ventricular systolic pressure decreased by 25%, aortic pressure by 36% and cardiac output by 32%. Right ventricular ejection fraction decreased by 57%, but left ventricular ejection fraction did not change significantly. Left ventricular transmural pressure and diastolic size decreased, and right ventricular diastolic size increased. Intrapericardial pressure increased and equalization of diastolic pressures was noted. Volume loading resulted in increased right ventricular systolic pressure and stroke work, increased aortic pressure and cardiac output and increased transmural pressure and diastolic size in both ventricles. Pericardiotomy resulted in further increases in right and left ventricular filling, stroke work and cardiac output, as well as resolution of equalized diastolic pressures. These results indicate that cardiac output in experimental right ventricular infarction increases with volume loading, which enhances left ventricular preload by augmenting right ventricular output. Elevated intrapericardial pressure affects filling of both ventricles and may play a role in the pathophysiology of low cardiac output in right ventricular infarction.

Fetal wound healing without scar formations, fibrosis, or contracture might be accompanied by major differences in the wound extracellular matrix. The matrix of fetal wounds is rich in hyaluronic acid, a glycosaminoglycan found in high concentrations whenever there is tissue proliferation, regeneration, and repair. Although hyaluronic acid is a critical molecule for both embryonic development and wound healing, no factor has yet been identified that modulates hyaluronic acid in a consistent manner. We describe here a substance present in fetal sheep serum that stimulates hyaluronic acid synthesis by cultured fibroblasts. This glycoprotein factor appears to be ubiquitous, present in fetal sheep and bovine serum, reaching a peak in each at 40% of the way through gestation. This factor is also present in amniotic fluid. It might control hyaluronic acid deposition. In turn, hyaluronic acid, by creating an extracellular environment permissive for cell motility and proliferation, might be critical for fetal development. We suggest that the same sequence of events underlie the unique properties observed in fetal wound healing.

The 12 mm Dacron conduit containing a porcine valve is the smallest valved conduit manufactured and is used in the youngest infants with the most diminutive pulmonary arterial system. The outcome of patients with such a conduit is unknown. Between 1975 and 1985 there were 49 hospital survivors after placement of a 12 mm extracardiac valved conduit from the right ventricle to the pulmonary artery. Follow-up is available in 42 patients, aged 1 to 16 months (mean 3.5) and weighing 2.5 to 8.7 kg (mean 3.8). Twenty-eight patients (67%) have undergone subsequent conduit replacement, and 11 (26%) are alive and asymptomatic with a mean follow-up of 56 months. There were three late deaths. The interval between implantation and conduit change was 4.5 to 101 months (mean 44), allowing a weight gain of 2.7 to 23 kg (mean 10.4) before reoperation at age 12 to 117 months (mean 49). Despite elevated right ventricular pressures equaling systemic values, 37% of these patients were clinically asymptomatic. The gradient across the 12 mm valved conduit before explantation ranged from 30 to 173 torr (mean 83) with an almost equal predilection for stenosis at the proximal anastomosis, valve, conduit, distal anastomosis, and main pulmonary artery. The intervening pulmonary artery growth determined the size of the replacement conduit, 14 to 25 mm (mean 16), and was the main factor influencing the results of reoperation. This study demonstrates that the 12 mm porcine valve-containing conduit affords palliation in this difficult subset of patients with the smallest pulmonary arterial tree.

Hepatic and renal failure developed in association with severe enteritis and hemorrhagic proctocolitis in a patient who had had a jejunoileal bypass 8 yr previously for morbid obesity. Parenteral antibiotic treatment abolished the systemic manifestations of the enteritis, but did not change the course of the hepatic and renal failure, and prolonged hemodialysis was necessary. Liver function improved in response to hyperalimentation. Take-down of the jejunoileal bypass resulted in immediate improvement of renal function, and hemodialysis could be discontinued. Although there is no direct evidence supporting this theory, the course of this patient suggested that the renal failure was functional in origin, and was caused by a toxin generated as a result of the intestinal bypass. We suspect that the toxin originated from bacteria within the blind bowel loop. Its delivery to the renal circulation was probably facilitated by increased absorption from the ulcerated large intestine and by impaired clearance by the diseased liver. When the bacterial flora were returned toward normal by take-down of the bypassed intestine, the quantity of circulating toxins probably decreased, which allowed renal function to improve.

Between 1975 and 1985, 125 infants 2 to 365 days old (majority, 30 days old or less) with coarctation of the aorta underwent surgical repair. Forty-seven patients (38%) had severe congestive heart failure (CHF), metabolic acidosis, and poor systemic perfusion. The predominant operative technique was synthetic patch aortoplasty (100 patients); the remaining 25 had an end-to-end anastomosis. There were no operative deaths. Perioperative complications were minimized with the synthetic patch technique (less than 15%). For patients surviving at least 3 months after repair, the arm-leg systolic blood pressure gradient was relieved in 82% (71/87) of the patients having patch aortoplasty versus 65% (15/23) of the patients with end-to-end anastomosis. Although the rate of reoperation between the two groups was similar (patch, 5 [6%]; end-to-end, 3 [13%], two of the reoperations in the patch group were for preexisting hypoplastic transverse aortic arch. Late deaths (20 patients, 16%) were due to other major associated cardiac anomalies. Patch aneurysms have not occurred. Expedient use of synthetic patch aortoplasty has decreased perioperative complications, relieved coarctation gradients for CHF, increased early survival even in the presence of complex or associated cardiac anomalies, and has an acceptable rate of recurrent coarctation (6 to 13%).