In: Anatomy and Physiology
What do you expect may happen to the heart rate in individuals with DCM and HCM in an attempt to compensate for decreased ejection fraction? Why?
In dilated cardiac myopathy the hearts ability to pump blood forcefully from left ventricle decreases because of the weakened and dilated ventricular chamber .Therefore in order to maintain ejection fraction heart increase the heart rate in beats per minute compared to normal people. Prolonged period of DCM can lead to heart failure, sudden cardiac death etc.
hypertrophic cardio myopathy is a decease with a characteristic thick and enlarged left ventricle of the heart .it's an asymmetric thickening and also the most common cardiac disease. In HCM stiffness and scaring of heart prevent its proper pumping function .The thickened muscle wall make the inside of the chamber smaller which results in inability to hold much blood inside it. That means less oxygenated blood is pumped throughout the body. This results in arrhythmia and heart rate will be faster to increase the supply of oxygenated blood throughout the body. Ejection fraction usually remains normal for years in HCM .