Cyanosis is a physical finding that can occur at any age but presents the greatest challenge when it occurs in the newborn. The cause is multiple, and it usually represents an ominous sign, especially when it occurs in association with neonatal sepsis, cyanotic congenital heart disease, and airway abnormalities. Cyanosis caused by abnormal forms of hemoglobin can also be life-threatening, and early recognition is mandatory to prevent unnecessary investigations and delay in management. Abnormal hemoglobin, such as hemoglobin M, is traditionally discovered by electrophoresis, so the newborn screen, which is mandatory in several states, is a useful tool for the diagnosis. Although acquired methemoglobinemia, caused by environmental oxidizing agents, is common, congenital deficiency of the innate reducing enzyme is so rare that only a few cases are documented in the medical literature around the world. We present a neonate with cyanosis as a result of congenital deficiency of the reduced nicotinamide adenine dinucleotide-cytochrome b5 reductase enzyme. This infant was found to be blue at a routine newborn follow-up visit. Sepsis, structural congenital heart disease, prenatal administration, and ingestion of oxidant dyes were excluded as a cause of the cyanosis by history and appropriate tests. Chocolate discoloration of arterial blood provided a clue to the diagnosis. A normal newborn screen and hemoglobin electrophoresis made the diagnosis of hemoglobin M unlikely as the cause of the methemoglobinemia (Hb A 59.4%, A2 1.8%, and F 38.8%). Red blood cell enzyme activity and DNA analysis revealed a homozygous form of the cytochrome b5 reductase enzyme deficiency. He responded very well to daily methylene blue and ascorbic acid administration, and he has normal growth and developmental parameters, although he shows an exaggerated increase in his methemoglobin level with minor oxidant stress such as diarrhea.
Pulsatile bidirectional Glenn is associated with better pulmonary artery growth, which might improve long-term outcomes after Fontan. However, it was associated with a higher postoperative complication rate.
Ventriculocoronary connections (VCCs), also called sinusoids, occur with hypoplastic left heart (HLH). Previous reports are limited to case reports, pathologic series, and surgical series with limited detail, which may underestimate the incidence and overestimate the severity of VCCs in HLH. A study was conducted to determine the incidence VCCs in HLH, their effect on survival, and their echocardiographic and clinical features. The echocardiograms and medical records of 100 consecutive neonatal HLH cases were analyzed. All had an aortic and a mitral valve diameter and a left ventricular (LV) volume less than Z-3. For palliation, Norwood, Sano, or hybrid procedures were used, and if the patient was alive, subsequent bidirectional Glenn and extracardiac Fontan procedures were applied. Cases were classified as manifesting mitral and aortic atresia (MAAA), mitral and aortic stenosis (MSAS), or mitral stenosis and aortic atresia (MSAA). All other diagnoses or any case with additional cardiac anomalies were excluded from the study. Overall, VCCs were found in 15% of the cases. They occurred in 56% of the MSAA subtype cases and were not statistically associated with a high mortality rate. However, in one case, large and multiple VCCs definitely caused or contributed to early death. All VCCs had a transmyocardial course, a turbulent color-Doppler flow, and a dominant usually retrograde systolic coronary artery flow pattern. The VCCs were associated (p < 0.05) with MSAA, endocardial fibroelastosis, and ascending aortic size less than 2 mm. As shown by the findings, 15% of the HLH patients had MSAA with VCCs. Unless the VCCs were large or extensive, they did not contribute to mortality. Detailed echocardiographic analysis of VCCs in HLH was feasible. Recent reports emphasize more severe cases.
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