Difficulties to enter the left ventricle during percutaneous transvenous mitral commissurotomy (PTMC)- our experiences of 80 cases with modified techniques oleh Abdul Momen, Md Zulfikar Ali, Naharuma Aive Hyder Chowdhury, Reaz Mahmud Huda, ABM Nurun Nobi, Ashraf Ur Rahman, Iftequar Alam, Lima Asrin Sayami, Md Abul Alam, Md Delwar Hossain, Samia Tasneem