Regional Myocardial Function and Response to Acute Afterload Increase in Chronically Anemic Fetal Sheep: Evaluation by Two-Dimensional Strain Echocardiography

Cardiac function and dysfunction in the fetus

“…33,34 In fetal sheep, chronic severe anemia leads to decreased longitudinal, radial, and circumferential strain with preservation of ejection fraction, possibly reflecting a state of very severe anemia with myocardial hypoxemia. 35 In adults, very severe anemia does result in decreased left ventricular systolic function. 36 It may be instructive to retrospectively review the ventricular function of human fetuses with anemia which resulted in fetal loss for evidence of similar decompensation in function.…”

“…cardiomegaly, ventricular dilation, and atrioventricular valve insufficiency, presumably when compensatory afterload reduction is overwhelmed. In fetal sheep, chronic severe anemia leads to decreased longitudinal, radial, and circumferential strain with preservation of ejection fraction, possibly reflecting a state of very severe anemia with myocardial hypoxemia 35. The development of increased A-wave reversal in the IVC, ductus venosus and finally pulsatility of the umbilical vein flow indicate progressively elevated diastolic pressure with further stages of severity 33,34.…”

Correlation Between Cardiac Tissue Doppler and Peripheral Vascular Doppler in the Anemic Fetus – An Additional Method to Determine the Transfusion Threshold?

“…The RV seems to compensate for stress. If there was great impairment of the myocardium, the PS should diminish [18,19]. It seems straightforward that the correlation of the PS with vascular Doppler parameters corresponds to the correlation of the PSV and PD with vascular Doppler parameters.…”

“…PSV (mm/s)18.7 (5.3 -63.9)15.8 (8.7 -41.5)24.7 (5.7 -72.8)25.5 (11.9 -50.1) PD (mm) 1.9 (0.8 -5.9) 1.9 (1.2 -4.5) 2.7 (1 -10.1) 2.3 (0.7 -6) relative PS -0.49 (-0.1 to -1.13) -0.29 (-0.07 to -0.47) 0.32 (0.04 -0.87) 0.34 (0.02 -1.34) Peak systolic tissue velocity (PSV), peak systolic displacement (PD), and relative peak systolic strain (PS) in various regions of interest (ROI). ROI 1, ROI 2: mid-segmental lateral wall of the right or left ventricle; ROI 3, ROI 4: basal segments of the right or left ventricle.…”

Fetal myocardial peak systolic strain before and after intrauterine red blood cell transfusion – a tissue Doppler imaging study

“…This means a massive volume challenge to the fetal heart [42] . Both the anemia and volume load of IUT can cause distress to the fetal heart [41] . Changes in V max and amount of blood fl ow have been proven in anemia [4,8,9,13,16,19,20,24,30] .…”