The right ventricular systolic to diastolic duration ratio: a simple prognostic marker in congenital diaphragmatic hernia?

AIMS

(i) To compare the ratio of right ventricular systolic to diastolic duration (SD/DD) in infants with congenital diaphragmatic hernia (CDH) and normal controls and (ii) to examine its association, if any, with outcomes in CDH.

METHODS

  Retrospective chart and echocardiographic review of consecutive neonates (<1 month old) with CDH and term controls without structural heart defects. Right ventricular SD/DD was calculated by a single reader.

RESULTS

Infants with CDH (n = 29) were comparable to controls (n = 27) in their mean (SD) age [2.2 (3.3) vs. 2 (4.0) days], birthweight [3 (0.67) vs. 3 (0.69) kg] and proportion of males (48.2% vs. 72.4%). The DD and SD/DD were significantly abnormal in the CDH group, compared to controls. Among infants with CDH, those who died (n = 15) and those who died or required ECMO (n = 17) had significantly shorter DD and higher SD/DD ratio. At a cut-off of 1.3, SD/DD ratio had a sensitivity of 92.8 (95% CI 64-99%) and specificity of 61.5 (32-85%) for prediction of mortality. Significant independent associations with mortality were observed with antenatal diagnosis (p = 0.003) and higher SD/DD ratio (p = 0.04).

CONCLUSION

The right ventricular SD/DD ratio is a sensitive objective prognostic marker in infants with CDH. Further studies incorporating SD/DD ratio as a guide to intervention are warranted.

Ventricular atriopeptin. Unmasking of messenger RNA and peptide synthesis by hypertrophy or dexamethasone

Left ventricular hypertrophy or treatment with dexamethasone caused a 2.5-fold to threefold increase in both immunoreactive atriopeptin (AP) and AP messenger RNA (mRNA), primarily in left ventricular tissue. The combined treatments increased immunoreactive AP and AP mRNA more than either treatment alone. In the animals in which cardiac hypertrophy had been produced by abdominal aortic constriction, there was a decrease in atrial levels of AP and an increase in plasma levels of immunoreactive AP. The increase in left ventricular immunoreactive AP was confirmed by immunohistochemical staining of tissue from hypertrophied and/or dexamethasone-treated rats. The mRNA accumulated in the left ventricle was identical to atrial AP mRNA, as judged by transcriptional start site and by size on Northern blots. Because the mass of ventricular tissue is substantially greater than that of atrial tissue, the induced mRNA levels may represent a total abundance approaching one third of the total AP mRNA in the atria. High performance liquid chromatographic purification of ventricular extracts primarily demonstrated the presence of the high molecular precursor and small amounts of C-terminal peptide AP. Induction of ventricular AP (mRNA and peptide) may represent regression of the tissue to an earlier developmental form. These data provide a unique example of regulation of AP biosynthesis in nonatrial tissue.