Tissue Doppler Assessment of Systolic Right Ventricular Function before and after Balloon Pulmonary Vulvuloplasty

Abstract
Background: The incidence of valvular pulmonary stenosis has been reported to be 0.6 to 0.8 per 1000 live births, and when associated with other congenital heart diseases as many as 50% of all patient with congenital heart diseases. The magnitude of right ventricular pressure and the pressure across the pulmonary valve are generally proportional to the degree of obstruction. Under usual circumstances, proportional right ventricular hypertrophy maintains normal pulmonary flow. If the normal output isn't maintained, right sided heart failure ensues. This occur in neonates with critical pulmonary stenosis and in patient with severe obstruction that occur in childhood or adulthood.
Aim of Study: To assess the right ventricular systolic function by tissue Doppler in patients with critical valvular pulmonary stenosis before, immediately and three months after successful Balloon Pulmonary Valvuloplasty (BPV).
Methods: This study is a prospective study, it included 20 patients with critical stenosis who attended to the Cardiology Department in Tanta University Hospital and subjected to balloon pulmonary valvuloplastyfrom August 2016 to March 2017. The patients are subjected to balloon valvuloplasty and full echocardiography assessment and tissue Doppler to the right ventricle.
Results: The transcutaneous BPV showed high efficacy in reducing the pressure gradient across the pulmonary valve denoting successful and effective dilatation, where the max-imum pulmonary PG ranged from 68-120mmHg. With a mean ± SD value of 82.47±16.3 at base line, and 12-30mmHg with a mean value of 20.26±5.43 immediately after intervention, and 15-35mmHg, with a mean ± SD value of 22.37±5.05 mmHg three months after intervention. There was statistically significant decrease in maximum pulmonary PG immediately after BPV (p=0.001), but there was no statistically significant difference in the maximum pulmonary PG immediately after intervention and after three months. TAPSE ranged from 11- 16mm with a mean ± SD value of 13.48±1.43 at base line, and 13-17mm with a mean ± SD value of 15.87±1.08 imme-diately after intervention.and 20-24mm with a mean ± SD value of 21.74±1.163 three months after intervention. There was statistically significance increase in TAPSE immediately after intervention and also three months after intervention. Right Ventricular Systolic wave (RVs) ranged from 8-11cm/s with a mean ± SD value of 9.24±0.77 at base line, and 8-11 cm/s with a mean ± SD value of 9.24±0.67 immediately after intervention and ranged from 11-14cm/s with a mean ± SD value of 12.41±0.67 three months after intervention. There was no statistically difference in RVs before intervention and immediately after intervention but RVs was statistically significance increased after three months from both before intervention and immediately after intervention.
Conclusion: BPV is safe and effective to relieve critical pulmonary stenosis. The balloon promotes advantageous changes in both, pulmonary annulus and pressure gradient across the RVOT, in addition, the Doppler gradient observation during the follow-up support the expectation that BPV is a curative therapy. The right ventricular systolic function changed favorably in children with moderately-severe pulmonary stenosis after successful balloon valvuloplasty. These changes provide a good insight for early intervention in the children with pulmonary stenosis to avoid progression to permanent cardiac deformation and heart failure.