Cardiac remodeling in preterm infants with prolonged exposure to a patent ductus arteriosus

Abstract

The preterm PDA induces early and significant remodeling of the left heart. A compensated cardiac physiology was seen with preserved systolic function, suggesting adaptive rather than pathological remodeling changes with prolonged exposure to a PDA.

Left atrium function and deformation in very preterm infants with and without volume load

“…Early diastolic flow velocities were not reported in this study, but the presence of an enlarged LA would suggest high blood flow over the mitral valve and thus a higher Ee’ ratio. Our group explored prolonged exposure to a PDA in preterm infants and found significant LA and LV remodeling and increased Ee’ ratio from 3 days up to 8 weeks after preterm birth . Systolic function was maintained throughout the period of exposure, suggesting that echocardiography evidence of LA dysfunction precedes ventricular dysfunction in PDA volume overload.…”

“…Several neonatal diseases are associated with increased ventricular filling pressure and atrium dysfunction. Volume overload due to a patent ductus arteriosus (PDA) is the commonest cause in preterm infants <30 weeks of gestation . The ductus arteriosus is a fetal vessel that connects the aorta and pulmonary artery, and supposed to close soon after birth.…”

Effect of patent ductus arteriosus on the heart in preterm infants

“…The left heart remodels to a larger and more spherical shape and thus significantly increases in volume with both left atrial and left ventricular dilation (Figure ). Most changes occur and peak in the first 4 weeks of volume overload, then plateau and return to the normal size, and shape over a 10‐week course . The wall thickness increases after 4 weeks of increased volume exposure.…”

“…The first mechanism is by lowering the afterload. In preterm infants with a PDA, the arterial blood pressure and effective arterial elastance are lower, but the ventricular elastance is unchanged . This leads to the decoupling of the ventricular and arterial systems.…”

“…Infants with a PDA have decoupling with reduced ventriculo‐arterial coupling with no changes in left ventricular stiffness. Hence, the PDA itself may be serving as an adaptation when the heart is incapable of increasing the contractility to maintain function . The second mechanism in managing the preload without increasing the contractility is possibly related to the patent foramen ovale (PFO) which is present in most preterm infants .…”