Percutaneous Transvenous Mitral Commissurotomy (PTMC) is the first line treatment for rheumatic mitral stenosis (MS). We sought to evaluate (1) changes in 2-dimensional (2D) echocardiographic and strain values and (2) differences in these values for patients in atrial fibrillation (AF) and sinus rhythm (SR) pre, immediately and 6months post PTMC. Retrospective study of 136 patients who underwent PTMC between 2011 and 2021. We analyzed their 2D echocardiogram, Global Longitudinal Strain (GLS), Left Atrial Reservoir Strain (LAr-S) and Right Ventricle Free Wall Strain (RVFW-S) pre, immediately and 6months post PTMC. At 6months, mitral valve area increases from 0.94 ± 0.23cm2 to 1.50 ± 0.42cm2. Ejection fraction (EF) did not change post PTMC (pre; 55.56 ± 6.62%, immediate; 56.68 ± 7.83%, 6months; 56.28 ± 7.00%, p = 0.218). Even though EF is preserved, GLS is lower pre-procedure; -11.52 ± 3.74% with significant improvement at 6months; -15.16 ± 4.28% (p < 0.001). Tricuspid annular plane systolic excursion (TAPSE) improved at 6months from 1.95 ± 0.43 to 2.11 ± 0.49 (p = 0.004). RVFW-S increases at 6months from -17.37 ± 6.03% to -19.75 ± 7.19% (p = 0.011). LAr-S improved from 11.23 ± 6.83% pre PTMC to 16.80 ± 8.82% at 6months (p < 0.001) post PTMC. Pre-procedure patients with AF have lower strain values (More LV, RV and LA dysfunction) with statistically significant difference for LAr-S (p < 0.001), GLS (p < 0.001) and RVFW-S (p < 0.001) than patients in SR. Patients with severe rheumatic MS have subclinical left and right ventricle dysfunction despite preserved EF and relatively normal TAPSE with significant improvement seen at 6months post PTMC. AF patients have lower baseline strain values than SR patients.