Human Anatomy: Heart
Read the content under "Chamber and circulation through heart," "Disorders of heart: heart defects," "Heart valves," "Congenital heart diseases" and "Myocardial infraction." (22 minutes)
OpenStax
Click https://cnx.org/contents/wpkg_88R@2.57:Y5T_wVSC@4/Heart-Anatomy link to open resource.