Case - HIE and LV Dysfunction

Case by Gabriel Altit

December 23rd, 2023

In this case report with clips, we detail the clinical course of a term neonate delivered at 39 weeks and 4 days with perinatal asphyxia (birth weight of 3840 grams). The baby was born in the context of meconium-stained amniotic fluid with severe acidosis on cord blood gas analysis (pH < 6.5), and high lactate. The pregnancy history was uneventful, with no reported gestational diabetes or hypertension. Occasional decelerations were noted before delivery, but there were no signs of abruptio or maternal bleeding. At birth, the baby was limp with no respiratory efforts. Immediate resuscitation efforts were initiated, including drying, stimulation, positive pressure ventilation, intubation and chest compressions due to a heart rate persistently below 60 bpm. The patient was admitted to the NICU and therapeutic hypothermia was initiated due to moderate encephalopathy.

The patient presented a clinical picture corresponding to persistent pulmonary hypertension with FiO2 at 100% and pre-post ductal differential of saturation.

An echocardiography was requested due to ongoing hypotension and concern for pulmonary hypertension. On echocardiography, the patent foramen ovale was left to right and restrictive, and the ductus was shunting mostly right to left. LV dysfunction was noticed (predominantly) with some mild RV dysfunction. Ventilation parameters were optimized to maintain pre-ductal oxygen saturation >95%. Epinephrine was initiated to provide inotropy and iNO was weaned in the context of the concern for post-capillary congestion.

Repeat echocardiography the day following epinephrine initiation demonstrated normalization of the biventricular function and epinephrine was weaned. The baby was extubated to room air one day following inotrope wean.

Initial echocardiographic evaluation

Subcostal view

Long axis subcostal outlining that the LV systolic function seems depressed, at least quatitatively.

Subcostal view with double panel. The PFO is left to right and resitrictive. This indicates that the LA pressure is higher than the RA pressure. This could be related to underlying increased LV end-diastolic pressure.

Subcostal view outlining some mitral insufficiency (mild) possibly secondary to papillary muscle subendocardial ischemia, often noticed in the newborns after an asphyxial event.

Trivial pulmonary insufficiency. The body and outflow tract of the right ventricle are observed in this subcostal view. This is a good sweep to outline part of the RV function, which is tripartite.

Parasternal long axis view

Parasternal long axis. Despite velocity filter at 55 cm/s (Nyquist) one may appreciate that there is minimal colour observed in the colour box. This outlines that the LV does not generate high velocities, a marker of decrease LV performance. One may also appreciate the mitral insufficiency that has an eccentric jet.

Mitral insufficiency observed in the PLAX

One may appreciate the significant LV dysfunction from the PLAX. The Mitral valve and Aortic valve are opening and closing, indicating flow through these valves. However, there is significant diskenesis of the septum and the posterior wall of the LV.

Parasternal short axis view

Aortic valve is opening and closing (no 2D signs of aortic stenosis). The pulmonary valve is opening and closing, outling that the RV is able to generate output.

The PDA is indicating a bidirectional shunt, mostly right to left. This indicates that the PA pressure are higher than the systemic pressure for a significant portion of the cardiac cycle (systolic).

Left coronary artery with normal anatomical configuration with flow in diastole. The coronary looks mildly dilated, often the case in newborns with asphyxia and increased right atrial pressure, increasing the coronary sinus pressure connected to the right atrium.