A prospective of 30 patients with symptomatic severe congenital valvular pulmonary stenosis who are indicated for percutaneous balloon pulmonary valvuloplasty . the aim is to

1. - evaluate electrical and mechanical remodeling of RV 6 months following balloon dilation
2. - evaluate Functional capacity using 6MWT and SaO2 before and 6 months following BPV

Valvular pulmonary stenosis (PS), defined as an obstruction of blood flow at the level of the pulmonary valve, is a form of congenital heart disease, described in 0.6-0.8 out of 1000 live births.

The main physiologic effect of valvular pulmonary stenosis (PS) is an increase in Right ventricular pressure proportional to the severity of obstruction. This elevation of RV pressure is accompanied by an increase in muscle mass where hyperplasia of the muscle cells with a concomitant increase in the number of capillaries occurs. In contrast, the adult myocardium responds with hypertrophy of the existing fibers, with no change in the capillary network. Percutaneous balloon pulmonary valvuloplasty (PBPV) is the procedure of choice for uncomplicated severe or symptomatic pulmonary stenosis. the aim is to

1. - evaluate electrical and mechanical remodeling of RV 6 months following balloon dilation
2. - evaluate Functional capacity using 6MWT and SaO2 before and 6 months following BPV

Inclusion Criteria:

• 1-Adult population with an age more than or equal to 16 years of age at time of procedure 2-Severe valvular Pulmonary stenosis defined as a PG max more than or equal to 64 mmHg measured by 2d echo before Procedure

Exclusion Criteria:

1. Patients with isolated supra-valvular and sub valvular pulmonary stenosis
2. Patients with peripheral pulmonary stenosis.
3. Patients with pulmonary stenosis if part of another congenital heart disease .
4. Patients with organically diseased Tricuspid valve
5. Patients with any significant shunt lesion which result in dilation in RV such as atrial septal defect.
6. Patients with right ventricular dysfunction due to arrhythmogenic right ventricular dysplasia (ARVD) or non compaction

Adult population with an age more than or equal to 16 years of age at time of procedure