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Rheumatic fever and rheumatic heart disease continue to be the major health problem in all developing countries including Bangladesh. Mitral stenosis (MS) affects right ventricular (RV) function as a result of myocardial and haemodynamic factors. Functional analysis of the right ventricle cannot be reliably evaluated by conventional echocardiography, because of its complex geometry and load dependence of ejection phase indices.
To assess right ventricular function before and after successful percutaneous mitral commissurotomy.
A prospective study was done in NICVD, Dhaka, Bangladesh during the period of August2007 to May2011. 225 patients with rheumatic mitral stenosis who underwent PTMC were evaluated by Doppler echocardiography during and 24-48 hours after procedure to assess right ventricular function. A group of 30 healthy age and gender-matched subjects served as controls. Multiple parameters of global and longitudinal RV function were assessed by conventional and tissue Doppler imaging echocardiography. The RV function was evaluated using the Tricuspid Annular Plane Excursion (TAPSE), the RV Tei index, and systolic myocardial velocities by Doppler tissue imaging peak isovolumic contraction (DTI(IVC)) and peak systolic (DTI(S)) at the lateral tricuspid annulus.
After PTMC Mitral Valve Area increased from 0.82 +/- 0.11 cm2 to 1.75 +/- 0.27 cm2 (p <0.01). LA size decreased from 48.27 +/-07.76 mm to 30.25 +/-08.52mm (p <0.05) and Mitral Valve Gradient (MVG) reduced from 26.23+/-5.69 mm Hg to 11.73 +/- 4.25 mm Hg (p<0.01). RV outflow tract fractional shortening (RVOTfs) increased from 55 +/-13% to 71 +/- 13% (P = 0.002). There was a significant decrease in systolic pulmonary artery pressure from 47.8 +/- 22.5 mmHg to 23.1 +/-11.4 mmHg (P = 0.02), in the RV Tei index from 0.42+/-0.026 to 0.27+/-0.11 (P = 0.021), in myocardial acceleration during isovolumic contraction (IVA) at the lateral tricuspid annulus from 0.35+/-0.12 m/s2 to 0.24+/-0.08 m/s2 (P = 0.022), and in isovolumic contraction velocities at the lateral tricuspid annulus from 12.06+/-2.67 cm/s to 9.42+/-2.93 cm/s (P=0.033). In contrast, tissue Doppler velocities at the septal tricuspid annulus remained unchanged.
Immediately after successful PTMC, significant decrease in RV contractility as assessed by IVA was observed whereas other parameters of infundibular and global RV function as assessed by RVOTfs and Tei index showed significant improvement.