J Vis Exp. 2026 Jul 14;(233). doi: 10.3791/70686.
ABSTRACT
Premature birth is strongly associated with cardiac dysfunction, including impaired ventricular function and altered cardiac structure, which can lead to progressive heart failure and other short- and long-term morbidities. However, the natural history of cardiac dysfunction in infants born prematurely is not well defined. In the lamb model of bronchopulmonary dysplasia with associated pulmonary hypertension (BPD-PH), lambs are delivered at 110-128 days gestation (full term is approximately 145 days) and mechanically ventilated. The lambs develop cardiopulmonary complications of prematurity, including alveolar simplification on lung histology, the hallmark of BPD, and signs of increased pulmonary vascular resistance on echocardiography, consistent with evolving BPD-PH. This article describes a protocol for serial assessment of cardiac morphometry and function by echocardiography in preterm and former preterm lambs (up to approximately two months postnatal age). The protocol was developed by adapting guidelines from the American Society of Echocardiography. Echocardiography is serially performed on intubated and moderately sedated lambs using a bedside ultrasound system. Atrial and ventricular dimensions, right and left ventricular function, and PH-related measurements are obtained at each echocardiographic assessment. Measurements are reproducible and correlate with clinical status. This echocardiography protocol for assessing cardiac structure and function in lambs enables characterization of BPD-PH and evaluation of therapeutic approaches.
PMID:42546058 | DOI:10.3791/70686