The incidence of aortic right coronary cusp (RCC) prolapse in outlet ventricular septal defect (VSD) is reported at 5%- 16%.
Detection of RCC prolapse is critical in patients with outlet VSD because this complication may cause permanent aortic regurgitation. Aortic regurgitation occurs due to a poorly supported RCC combined with the venturi effect due to the VSD jet resulting in cusp prolapse.
This is an indication for VSD closure even if VSD is small and restrictive.
Case
An 8 month old baby presented to us with poor weight gain and recurrent episodes of fast breathing. On examination a grade 4 pan-systolic murmur was present at the lower left sternal area with a grade 3 diastolic murmur at the second right intercostal space. Echocardiogram showed a restrictive outlet VSD with RCC prolapse resulting in significant aortic regurgitation (figures 1-3). The child was immediately sent for VSD closure.Apical 4 chamber view showing subaortic restrictive Ventricular septal defect (L-R shunt).Parasternal Long axis view showing significant RCC prolapse.Parasternal Long axis view showing Aortic Regurgitation through venturi effect created by RCC prolapse through VSD.