CVPR Week 9: Heart Failure Flashcards
Objectives
Heart failure definition
Heart failure epidemiology
Causes of heart failure results in disorders of?
6 listed
What are cardiomyopathies?
- diseases or conditions that affect the myocardium
- can lead to LV dysfunction and possibly heart failure
Cardiomyopathy types
Causes of heart failure
Assessment of function of heart
What is the first test to evaluate heart failure?
Echocardiography
EF AKA
Ejection fraction
EF description
percentage of blood volume in the ventricle pumped out with each beat
EF =
LVEDV - LVESV
LVEDV
Echocardiography
Types of heart failure
- heart failure w/ reduced ejection fraction
- heart failure w/ preserved ejection fraction
What is systolic HF?
systolic heart failure
HF with Left Ventricular (LV) ejection fraction (LVEF) <= 40%
What is diastolic HF
diastolic heart failure is Heart failure with a preserved ejection fraction
Diastolic HF =
LV EF >= 50%
Borderline diastolic HF =
LVEF 41 - 49%
Systolic HF =
LVEF <= 40%
Prevalence of diastolic HF =
~50%
Heart failure types and ejection fraction equations
Pathophysiology of heart failure
- an index event damages the heart muscle and produces a decline in the pumping capacity of the heart (LV dysfunction)
- Neurohumoral systems are activated
- Initially this increased activity maintains perfusion of vital organs and systems attempt to compensate for the damage of the index event but with time damage the heart
- Heart failure progresses as a result of the overexpression of these systems
Neurohumoral systems that attempt to compensate for heart failure
- Sympathetic nervous system
- Renin-Angiotensin-Aldosterone-System
- Vasopressin release
- Cytokine release
The pathways of pathology in heart failure
Deleterious neurohormones involved with the pathogenesis of heart failure
- increased preload (increased volume) and afterload (increased pressure)
- sodium and water retention
- vasoconstriction
- Impaired diastolic and systolic function
- myocyte hypertrophy and myocardial fibrosis
- These lead to ventricle remodeling and eventually cell death
Ventricular remodeling occurs in heart failure as a response to?
Increased preload and afterload (increased volume and pressures) from sodium and water retention as well as vasoconstriction causes ventricular hypertrophy and cell death
These changes in myocardial size and shape are associated with cell death
What is the result of ventricular remodeling in heart failure?
These changes in myocardial size and shape are associated with cell death
Why does cell death occur in heart failure?
the conditions and ventricular remodeling that takes place causes a cycle of increased stress leading to further acceleration of cell death and fibrosis
Describe how the sympathetic nervous system is involved in the pathophysiology of heart failure
sympathetic activation initially helps to maintain cardiac output
The initial increase in NE levels causes
- increased cardiac contractility
- increased heart rate
- helps maintain the glomerular filtration rate
The long-term increase in NE levels causes
- Increased afterload (vasoconstriction)
- Fibrosis
- Arrhythmias
The long-term increase in NE levels from sympathetic activation in heart failure causes
- Increased afterload (vasoconstriction)
- Fibrosis
- Arrhythmia
The initial increase in NE levels from sympathetic activation in heart failure causes
- increased cardiac contractility
- increased heart rate
- helps maintain the glomerular filtration rate
Describe the role of the RAAS in heart failure pathophysiology
Poor cardiac output causes reduced renal perfusion which stimulates renin release
The increased renin produces angiotensin II which causes
- efferent glomerular arteriolar vasoconstriction
- vasoconstriction
- increases aldosterone synthesis which causes
- more Na+ reabsorption and K+ excretion
The overall effect results in an increased afterload leading to further reduction in cardiac output and even worse renal perfusion and increased preload due to the Na+ and water retention
Describe the role of vasopressin iin heart failure
Vasopressin is released from the posterior pituitary gland which is a potent vasoconstrictor causing increased afterload and also it promotes water reabsorption in the renal tubules