Altered biventricular function in neonatal hypoxic-ischaemic encephalopathy: a case-control echocardiographic study

Background: In newborns with hypoxic-ischaemic encephalopathy, more profound altered right and left ventricular function has been associated with mortality or brain injury. Mechanisms underlying cardiac dysfunction in this population are thought to be related to the persistence of increased pulmonary vascular resistance and myocardial ischaemia. We sought to compare cardiac function in newborns with hypoxic-ischaemic encephalopathy to controls using echocardiography. Methods: We did a retrospective case-control study with moderate or severe hypoxic-ischaemic encephalopathy between 2008 and 2017. Conventional and speckle-tracking echocardiography measures were extracted to quantify right and left ventricular systolic and diastolic function. Fifty-five newborns with hypoxic-ischaemic encephalopathy were compared to 28 controls. Results: Hypoxic-ischaemic encephalopathy newborns had higher estimated systolic pulmonary pressure (62.5 +/- 15.0 versus 43.8 +/- 17.3 mmHg, p < 0.0001) and higher systolic pulmonary artery pressure/systolic blood pressure ratio [101 +/- 16 (iso-systemic) versus 71 +/- 27 (2/3 systemic range) %, p < 0.0001]. Tricuspid annular plane systolic excursion was decreased (7.5 +/- 2.2 versus 9.0 +/- 1.4 mm, p = 0.002), E/e' increased (7.9 +/- 3.3 versus 5.8 +/- 2.0, p = 0.01), and right ventricle-myocardial performance index increased (68.1 +/- 21.5 versus 47.8 +/- 9.5, p = 0.0001) in hypoxic-ischaemic encephalopathy. Conventional markers of left ventricle systolic function were similar, but e' velocity (0.059 +/- 0.019 versus 0.070 +/- 0.01, p = 0.03) and left ventriclemyocardial performance index were statistically different (77.9 +/- 26.2 versus 57.9 +/- 11.2, p = 0.001). The hypoxic-ischaemic encephalopathy group had significantly altered right and left ventricular deformation parameters by speckle-tracking echocardiography. Those with decreased right ventricle-peak longitudinal strain were more likely to have depressed left ventricle-peak longitudinal strain. Conclusion: Newborns with hypoxicischaemic encephalopathy have signs of increased pulmonary pressures and altered biventricular systolic and diastolic function.