Persistence of pulmonary arterial hypertension after relief of left sided obstructive lesions in small infants: our experience

Abstract

Background: Infants with critical left sided obstructive lesions usually present with left ventricle dysfunction and pulmonary arterial hypertension (PAH). Left ventricular dysfunction and pulmonary artery pressures usually normalize after relief of obstruction. In some, PAH persists despite adequate relief of obstruction.

Patients and methods: We retrospectively reviewed records of infants (less than 3 months) who underwent intervention for left sided obstruction (n=50) over four years (May 2012-May 2016).

Result: We report four infants who had persistent of PAH despite relief of left sided obstruction. The causes of PAH were found to be high left ventricular end diastolic pressure(n=1), severe hypoplasia of pulmonary veins (n=1), stenosis of the lower branch of the right pulmonary artery (n=1) and non-regression of pulmonary vascular resistance (n=1).

Conclusion: That persistence of PAH after relief of obstruction should be investigated and other, less common causes should be sought.

Figure 1a

Suprasternal short axis view with color Doppler interrogation showing mosaic flow in lower branch of right pulmonary artery (arrow) suggestive of stenosis. 1b: Continuous wave Doppler interrogation of lower branch of RPA showing velocity of 316 cm/sec (peak gradient of 40 mmHg with pandiastolic spilling) suggestive of severe stenosis of that branch.

Figure 2a

Post balloon dilatation of lower branch of right pulmonary artery, color Doppler interrogation showing laminar flow (arrow) suggestive of normal pattern. 2b: Continuous wave Doppler interrogation of lower branch of RPA showing velocity of 122 cm/sec (peak gradient of 6 mmHg) suggestive of no stenosis

Figure 3

Three Dimensional reconstruction of CT angiography of pulmonary veins showing: A. Severe stenosis of right superior pulmonary vein (RSV) and B. Severe stenosis of left inferior pulmonary vein (LIV).