Diseased, replaced or repaired mitral valve can lead to restricted blood flow to left ventricle and inadequate flow in left ventricular assist device (LVAD). A middle age woman with 'burnt out' hypertrophic cardiomyopathy had mitral valve repair for mitral regurgitation. She needed LVAD to support severe decompensating heart failure. Repaired mitral valve posed a risk of restricted flow through the device. Mitral commissurotomy was performed on beating heart through the left ventricular apical hole created for insertion of inflow cannula of LVAD.