Pediatric research
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BackgroundPostnatally, the immature left ventricle (LV) is subjected to high systemic afterload. Hypothesizing that LV pumping would change during transition-adaptation, we analyzed the LV in preterm infants (GA≤32+6), clinically stable or with a hemodynamically significant patent ductus arteriosus (hPDA) by applying a pump model. MethodsPumping was characterized by EA (effective arterial elastance, reflecting afterload), EES (end-systolic LV elastance, reflecting contractility), EA/EES coupling ratios, descriptive EA:EES relations, and EA/EES graphs. ⋯ Therefore, LV pumping was characterized by a lower EA/EES coupling ratio (P=0.088) throughout transition-adaptation. ConclusionsIn stable infants, facing high afterload, the immature LV, enhanced by the physiological PDA, increases its contractility. In hPDA, facing low afterload, the overloaded immature LV exhibits a consistently lower contractility.