Heart Falliure

Heart Failure

• its simply the heart can not perform its function properly
• at the end of the filling period (diastolic period) we have the end-diastolic volume (EDV) in the left ventricle, which is also called the pre-load, after that pumping will start ejecting the blood, and that is the systole and at the end of the systolic period we still have some blood stay in the ventricle because not all blood will be ejected by systole, some of blood will stay between the papillary muscle and the wall of the left ventricle and those of the right ventricle and this volume will be the end-systolic volume (ESV), the difference between these two volumes is the stroke volume (cardiac output). 
• now if we dived the stroke volume by EDV we will be able to know how much of the EDV will be ejected and this is called the Ejection Fraction (E.F.)
• E.F. is the ratio between the stroke volume and the EDV normally must be over 50%. 
• when the E.F. is less than 50% this sign of heart faliure 
• note: the preload is the EDV, end diastolic pressure of the left ventricle and after load is the preipheral resistance
• types of heart failure: the first two types either the left ventricular failure or the right ventricular faliure and if both of them occur together we call this congestive heart failure or the second two types an acute or chronic. 
• acute: is something happen suddenly as in case of myocardial infraction 
• chronic or progressive as in case of patient with valvular disease or hypertension. 
• when the left ventricle fail, it can not pump, the blood will stay in the ventricle, the ventricle then can not receive the blood from the left atrium so the blood in the left atrium will increase and pressure will increase and then the blood will stay in the pulmonary circulation and this will lead to congestion of fluid in the lung in the alveoli so this will affect the exchange of oxygen in the alveoli and this will lead to dyspnea which is hunger of air.