Background: The prognosis for pulmonary atresia and intact ventricular septum (PAIVS) has been poor. Our hypothesis is that intrinsic abnormal left ventricular (LV) intramyocardial circulation might be related to the poor outcomes of these patients. Methods:Neonatal heart specimens were examined microscopically in four groups of 6 cases each. Group I had PAIVS with ventriculocoronary artery connections (VCAC), group II had PAIVS without VCAC, group III had normal hearts, and group IV had LV hypertrophy. A projection microscope with grid overlay was used to count the LV intramyocardial coronary artery density (IMCAD), which was expressed as the number of profiles/mm2. Results: The LV IMCAD of groups I (0.40 ± 0.14/mm2) and II (0.45 ± 0.15/mm2) were significantly lower than those of groups III (0.77 ± 0.11/mm2) and IV (0.76 ± 0.09/mm2; all with p = 0.002). There was no significant difference between either groups I and II (p = 0.394) or groups III and IV (p = 0.818). Conclusions: This study demonstrates lower LV IMCAD in a widely heterogeneous spectrum of neonatal hearts with PAIVS, which might potentially predispose these patients to myocardial ischemia and in turn contribute to the poor prognosis of this disease.

UNLABELLED:Anomalous origin of one pulmonary artery from the ascending aorta is an uncommon lesion with an uncertain outcome. We reviewed 16 consecutive children (9 males) presenting with this lesion over a 36 year period at a single institution. Median age at presentation was 2 days (range, birth to 3.2 years). The anomalous pulmonary was the right in 12 and the left in 4, all originating from the proximal ascending aorta, with no patient having stenosis at the origin of the anomalous pulmonary artery. Associated cardiac anomalies were noted in 9 patients. No intervention was attempted in 2 patients: one was deemed inoperable due to complex associated lesions and pulmonary vascular obstructive disease, while the other one died before repair. Surgical intervention was attempted in 14 patients, with 3 intraoperative deaths (21%). Of 11 operative survivors, 8 developed pulmonary arterial stenosis graded severe in 2, moderate in 1 and mild in 5. Patients with severe stenosis required surgical angioplasty, 1 after unsuccessful dilation combined with placement of an endovascular stent. One patient with moderate, and one with mild, stenosis underwent successful transcatheter balloon dilation. The remaining 4 patients with mild stenosis remain unchanged during follow-up. One patient had biopsy evidence of pulmonary vascular obstructive disease at 3.3 years of age. There were no late deaths, giving a total mortality of 25% (4/16).CONCLUSION:While early diagnosis and repair of anomalous origin of one pulmonary artery from the ascending aorta is necessary, restenosis of the site of repair is common.