Sleep in infants with congenital heart disease.

OBJECTIVES: To investigate hypoxia and sleep disordered breathing in infants with congenital heart disease. METHODS: Prospective study. In-hospital full polysomnography was performed on 14 infants with congenital heart disease, age 7 +/-1 months, and in 7 normal infants, age 10 +/-2 months. Congenital heart disease infants were classified as acyanotic (n=7) or cyanotic (n=7). RESULTS: Nutritional status, assessed by the Gomez classification and expressed as % weight for age, was 70 +/-7, 59 +/-11 and 94 +/-16 in the acyanotic, cyanotic congenital heart disease and control infants, respectively (p<0.001). The respiratory disturbance index (AHI, events per hour) was [median (25-75%)]: 2.5 (1.0-3.4), 2.4 (1.5-3.1) and 0.7 (0.7-0.9) in acyanotic, cyanotic CHD infants and controls, respectively (p=0.013). Almost all congenital heart disease infants (11 out of 14) and only one control infant had an AHI >1 event/hour. The minimum oxygen saturation was 79% (74-82), 73% (57-74) and 90% (90-91) in the acyanotic, cyanotic congenital heart disease infants and controls, respectively (p <0.001). The arousal index (events/hour) was similar among the three groups at 8.4 +/-2.4, 10.3 +/-8.7 and 6.5 +/-3, respectively (p=0.451). CONCLUSIONS: Infants with congenital heart disease frequently present with sleep-disordered breathing associated with oxygen desaturations but not arousals. Therefore, sleep may represent a significant burden to infants with congenital heart disease.

ALDH1A2 (RALDH2) genetic variation in human congenital heart disease.

BACKGROUND: Signaling by the vitamin A-derived morphogen retinoic acid (RA) is required at multiple steps of cardiac development. Since conversion of retinaldehyde to RA by retinaldehyde dehydrogenase type II (ALDH1A2, a.k.a RALDH2) is critical for cardiac development, we screened patients with congenital heart disease (CHDs) for genetic variation at the ALDH1A2 locus. METHODS: One-hundred and thirty-three CHD patients were screened for genetic variation at the ALDH1A2 locus through bi-directional sequencing. In addition, six SNPs (rs2704188, rs1441815, rs3784259, rs1530293, rs1899430) at the same locus were studied using a TDT-based association approach in 101 CHD trios. Observed mutations were modeled through molecular mechanics (MM) simulations using the AMBER 9 package, Sander and Pmemd programs. Sequence conservation of observed mutations was evaluated through phylogenetic tree construction from ungapped alignments containing ALDH8 s, ALDH1Ls, ALDH1 s and ALDH2 s. Trees were generated by the Neighbor Joining method. Variations potentially affecting splicing mechanisms were cloned and functional assays were designed to test splicing alterations using the pSPL3 splicing assay. RESULTS: We describe in Tetralogy of Fallot (TOF) the mutations Ala151Ser and Ile157Thr that change non-polar to polar residues at exon 4. Exon 4 encodes part of the highly-conserved tetramerization domain, a structural motif required for ALDH oligomerization. Molecular mechanics simulation studies of the two mutations indicate that they hinder tetramerization. We determined that the SNP rs16939660, previously associated with spina bifida and observed in patients with TOF, does not affect splicing. Moreover, association studies performed with classical models and with the transmission disequilibrium test (TDT) design using single marker genotype, or haplotype information do not show differences between cases and controls. CONCLUSION: In summary, our screen indicates that ALDH1A2 genetic variation is present in TOF patients, suggesting a possible causal role for this gene in rare cases of human CHD, but does not support the hypothesis that variation at the ALDH1A2 locus is a significant modifier of the risk for CHD in humans.

Sleep in infants with congenital heart disease

OBJECTIVES: To investigate hypoxia and sleep disordered breathing in infants with congenital heart disease. METHODS: Prospective study. In-hospital full polysomnography was performed on 14 infants with congenital heart disease, age 7 ±1 months, and in 7 normal infants, age 10 ±2 months. Congenital heart disease infants were classified as acyanotic (n=7) or cyanotic (n=7). RESULTS: Nutritional status, assessed by the Gomez classification and expressed as percent weight for age, was 70 ±7, 59 ±11 and 94 ±16 in the acyanotic, cyanotic congenital heart disease and control infants, respectively (p<0.001). The respiratory disturbance index (AHI, events per hour) was [median (25-75 percent)]: 2.5 (1.0-3.4), 2.4 (1.5-3.1) and 0.7 (0.7-0.9) in acyanotic, cyanotic CHD infants and controls, respectively (p=0.013). Almost all congenital heart disease infants (11 out of 14) and only one control infant had an AHI >1 event/hour. The minimum oxygen saturation was 79 percent (74-82), 73 percent (57-74) and 90 percent (90-91) in the acyanotic, cyanotic congenital heart disease infants and controls, respectively (p <0.001). The arousal index (events/hour) was similar among the three groups at 8.4 ±2.4, 10.3 ±8.7 and 6.5 ±3, respectively (p=0.451). CONCLUSIONS: Infants with congenital heart disease frequently present with sleep-disordered breathing associated with oxygen desaturations but not arousals. Therefore, sleep may represent a significant burden to infants with congenital heart disease.

Doppler flow evaluation can anticipate abnormal left lung perfusion after transcatheter closure of patent ductus arteriosus.

AIMS: Coil protrusion into the left pulmonary artery (LPA) has been described after transcatheter closure of the patent ductus arteriosus (PDA). The possible impact of such a finding in lung perfusion has not been completely clarified. We evaluated Doppler flow velocities and lung perfusion in patients submitted to that procedure. METHODS: After transcatheter closure of PDA with coils, 70 patients (mean age 8.6+/-3.4 years) were followed for a period of 3.6+/-0.9 years (range 2.1-5.9) and compared to 22 controls. Peak flow velocities and coil protrusion were assessed by Doppler echocardiography. A Doppler velocity index (DVI) was calculated by the difference between the LPA and right pulmonary artery (RPA) peak flow velocities relative to the pulmonary trunk (PT) expressed in percentage, as follows: DVI=(LPA velocity - RPA velocity)/PT velocity x 100. Lung scintigraphy was performed using (99m)Tc-labelled macro-aggregated albumin. RESULTS: Device protrusion was observed in 94% of the patients, 10% of whom presented abnormal left lung perfusion. Peak LPA velocity and DVI were significantly greater in patients (p=0.001) and correlated negatively with left lung perfusion values (R(2)=0.21 and R(2)=0.65, respectively). A cut-off value of 50% for the DVI showed high sensitivity and specificity for reduced lung perfusion. CONCLUSION: Impaired left lung perfusion may appear following transcatheter closure of PDA with coils and the determination of DVI may anticipate such alteration.

Morphology of the internal elastic lamina in arteries from pulmonary hypertensive patients: a confocal laser microscopy study.

The development and progression of pulmonary hypertension lesions involve continuous remodeling of the arterial wall, including the extracellular matrix components. The integrity of the internal elastic lamina may represent a barrier to cell migration and formation of intimal proliferative lesions. Some patients with congenital cardiac shunts develop precocious intimal occlusive lesions,whereas others evolve with isolated medial hypertrophy. We studied the 2-D and 3-D morphology of the internal elastic lamina of peripheral pulmonary arteries to search for any difference regarding the type of histological lesion. Fifteen lung biopsies collected for diagnostic purposes from patients with congenital shunts and 6 control lungs (mean ages, 15.8 and 14.7 mo) were studied using the confocal laser scanning microscope, under predetermined conditions of laser intensity, brightness and contrast. We measured the thickness of the internal elastic lamina and determined the number of gaps and projections of elastic tissue towards the medial and intimal layers. The mean internal elastic lamina thickness was significantly higher in arteries from cases with isolated medial hypertrophy when compared with controls and to those with proliferative lesions (P <.05). The number of gaps of the internal elastic lamina was higher in arteries >100 micro m in diameter from the group with intimal lesions when compared to the cases presenting with isolated hypertrophy, but did not differ from the controls. There was a positive linear correlation between the external arterial diameter and the thickness of the internal elastic lamina (r =.74, P <.001) in cases presenting isolated medial hypertrophy. The increased thickness and smaller number of gaps of the internal elastic lamina may act as a barrier that prevents smooth muscle cell migration in patients with pulmonary hypertension without intimal proliferative lesions. On the other hand, a greater number of gaps does not represent, by itself, unrestrained migration, because controls also showed fenestrated laminae.

Agenesia de valva pulmonar. Avaliação clínico-cirúrgica de 32 pacientes / Absent Pulmonary Valve. Clinical and Surgical Evaluation of 32 Patients

PURPOSE--To study the surgical and clinical evolution of 32 cases with absent pulmonary valve to propose the ideal period of time for surgical correction. METHODS--Clinical and laboratorial analysis were performed in 32 infants, under 12 months of age, between 1980 an 1993, in an evolutive character. From the clinical viewpoint, hypoxic and/or congestive features were considered in previous and late periods related to surgical repair. Laboratorial studies as ECG (cavities overload), chest X-ray (cardiac size and pulmonary vascular markings) and echocardiogram (associated defects, pressure gradients and anatomical aspects of pulmonary arteries) were also analyzed. Cardiac catheterization was performed in 15 patients. RESULTS--Early cyanosis in 84 of cases and "to and for "murmur in 90 of them facilitate clinical diagnosis in whom tetralogy of Fallot was associated in 30 patients. Refractory respiratory and cardiac insufficiency were responsible for operative indication in 12 patients, half of them, operated on under 12 months of age, died. Survival patients were repaired between two to 11 years old. Four deaths occurred early in life, before any surgical consideration and the 16 remaining patients will electively be considered for an opportune repair. CONCLUSION--Conservative clinical treatment is indicated, waiting for a more rigid bronchial wall can support the pressure of the dilated pulmonary arteries. This way, surgical repair is postponed for at least two years of age.