Akhteruzzamanm, M, A Rahman, MA Rahman, R Amin, MNA Miah, AR Khan, TA Chowdhury, A Hossain, and MA Kashem. 2013. “Relationship Between Ventricular Asynchrony and QRS Duration in Patients With Left Ventricular Systolic Dysfunction”. Bangladesh Journal of Medicine 23 (2):52-58. https://doi.org/10.3329/bjmed.v23i2.14984.