Table 1

Cardiac function and shunt changes in persistent pulmonary hypertension of the newborn (PPHN) (see figure 1)

ParameterNormalMild-to-moderate PPHNSevere PPHN
RV afterloadNormal↑↑↑
RV contractilityNormal↑↑ with RV hypertrophy↓↓ (uncoupling) with RV dilation
RV diastolic functionNormalNormal/↓↓↓*
Septal positionBulging to the rightMidlineBulging to the left
PFO shuntLeft-to-rightBidirectional or right-to-leftRight-to-left (or left-to-right with LV dysfunction)†
PDA shunt (if open)Left-to-rightBidirectional or right-to-leftRight-to-left (or closing ductus)
LV preloadNormalNormal/↓Normal/↓
Systemic blood pressureNormalNormal/↓↓↓↓↓
  • *In the presence of moderate to severe PPHN, RV diastolic function (lusitropy) is significantly reduced. In such states, it is important to avoid chronotropic agents (which will exacerbate diastolic dysfunction) and to use agents which specifically target diastolic function (eg, milrinone).

  • †In some patients with severe PPHN, a bidirectional atrial shunt or a left-to-right shunt may be observed even in the absence of LV dysfunction.55

  • LV, left ventricular; PDA, patent ductus arteriosus; PFO, patent foramen ovale; RV, right ventricular.