Left ventricular systolic and diastolic function in term neonates after mild perinatal asphyxia.

To assess possible changes in myocardial contractile function and relaxation occurring after mild perinatal asphyxia, maximal blood pressure and M-mode echocardiograms were registered simultaneously in 32 normal full-term neonates and in 22 full-term asphyxiated neonates. The slope of the end-systolic pressure-dimension relation (ESPDR) was used as a reliable index for evaluation of myocardial contractility. A nonpharmacological afterload increase was performed to calculate this relation. The following most prominent changes were observed in asphyxiated neonates: slope of ESPDR 5.9 vs 14.4 mmHg/(cm/m2); normalized peak rate of left ventricular (LV) filling 2.14 vs. 4.11 s(-1); LV isovolumic relaxation period 63 vs 36 ms. These results suggest that ESPDR and parameters of LV relaxation and filling may serve as early and sensitive signs of hypoxic myocardial dysfunction.