Pathophysiology of Heart Failure Flashcards
How does contractility shift the Frank-Starling curve?
Decreased contractility shifts the curve downward
HF can cause a decrease in contractility and an increase in the workload of the heart
Higher and higher levels of preload lead to:
An increase in the workload of the heart
A non-normal SV
What does aldosterone do to blood volume?
Regulates sodium (increases retention)
Leads to an increase in water retention/volume retention
What does vasopressin/ADH do to blood volume?
Regulates water
Increases retention of water –> increase in volume
What do ANP and BNP do to blood volume?
Regulate sodium
Increase excretion –> decreased water retention –> decreased volume
What are the two types of HF based on heart function?
Systolic: Heart Failure with Reduced Ejection Fraction (HFrEF)
Diastolic: Heart Failure with Preserved Ejection Fraction (HFpEF)
What are the two types of HF based on heart anatomy?
Left HF
Right HF
What is heart failure defined as?
The inability of the heart to produce enough cardiac output to meet the needs of the body
What is ejection fraction?
The % of blood volume in the LV at EDV that is actually ejected into the systemic circulation
Blood pumped out/total blood in the ventricle
What is systolic heart failure? What is it also called?
Impaired ability of the ventricle to contract, reducing stroke volume and ejection fraction to <40%
Generally occurs due to a thinned, weakened heart wall
Known as HFrEF: “Heart Failure with Reduced Ejection Fraction”
What has happened to the heart during HFrEF/systolic heart failure? Why has this happened?
The ventricle things
Chamber gets larger
Myocytes apoptose and are eventually replaced with stiff fibrotic tissue
Ventricles dilate
No longer has a good shape or structure for contracting/pumping
Occurs due to chronically increased preload and associated chronically elevated end-diastolic pressures
Etiology of systolic/HFrEF:
- Coronary artery disease/MI
- HTN
- Valve disorders
- Smoking
- Diabetes
- Toxic damage to the heart
- Dilated cardiomyopathy
- Idiopathic
The heart and chamber become ____ in HFrEF:
Bigger
What is diastolic heart failure? What is it also known as?
Impaired relaxation of the ventricle decreases the amount of filling and end-diastolic volume (SV)
Also called HFpEF: “Heart Failure with Preserved Ejection Fraction”
What happens to stroke volume, contractility, afterload, and ejection fraction in diastolic/HFpEF?
Contractility and EF are fairly normal
Afterload increases
Stroke volume is decreased due to poor filling and increased pressure (afterload)
How is the heart remodeled in diastolic/HFpEF? Why does this happen?
Ventricular wall hypertrophy, thickening (w/ accompanying stiffness)
Usually a response to chronically increased afterload, such as uncontrolled HTN
The chambers in diastolic/HFpEF become ___:
What does this cause?
Smaller
Less blood fills the chamber, decreased SV