Heart Failure Flashcards
Define heart failure.
What are the 3 “cardinal manifestations”?
Structural or functional cardiac defect that impairs the hearts ability to fill with or eject a sufficient amount of blood to supply the body or to do so only with elevated filling pressures.
- dyspnea- shortness of breath
- fatigue due to low CO
- volume overload (pulmonary or systemic edema)
In the majority of patients with HF, symptoms are due to ___________dysfunction.
LV
Heart failure is ALWAYS due to some underlying cardiac pathology. Defining this is important for management and treatment.
What “underlying pathology” accounts for 2/3 of patients with heart failure due to systolic dysfunction.?
CAD
What are the 7 etiologies of heart failure?
- coronary artery disease
- hypertension
- primary cardiomyopathy (restrictive, hypertrophic, dilated)
- valvular disease
- pericardial disease
- toxins (alcohol, chemo, radiation)
- inflammation (post-partum/ viral)
What is the primary inciting factor for patients with systolic dysfunction?
injury or stress to the myocyte
Acute stess - MI
Chronic stress - hypertension, adverse remodeling, hemodynamic stress due to valve disease)
What is remodeling?
What are the effects of remodeling on preload, afterload and CO?
Progressive changes in the ventricle in response to injury or stress (MI, hypertension, valvular defect, shunting)
- dilation
- hypertrophy
- more spherical shape
Enlargement of the ventricle will increase preload (which is initially helpful to maintain CO due to frank-starling forces)
Remodelling increases afterload negatively effecting ventricle performance.
CO is maintained at first but then starts to decline
In addition to changing the shape of the heart and eventually decreasing LV function and SV, what else can result from adverse ventricular remodeling?
What are the short term and long term effects?
It can activate endogenous neurohumoral systems like SNS and RAAS.
SNS- vasoconstriction and stimulation of myocardial growth (hypertrophy). This increases contractility in the short term, but in the long term has high O2 expenditure leading to more cell death.
RAAS- salt and water retention and increased PVR which in short term increases preload but long term increases myocardial energy expenditure–> cell death
Describe the neurohumoral activation of HF.
- myocardial injury
- decreased LV performance, increased wall stress
- activation of SNS and RAAS
- cell alterations lead to hypertrophy, fibrosis, apoptosis
- MORE remodeling- decrease LV function-> pump failure and arrhythmia
- Vasoconstriction and hemodynamic alterations lead to fatigue, DOE, pulm congestion, edema
What assessment is critical to establish the diagnosis of systolic or diastolic cardiac dysfunction?
LVEF= LVEDV-LVESV / LVEDV and it should be around 55%.
With systolic dysfunction, cardiac chambers are dilated and contraction is abnormal so you will see a LVEF less than 40%
With diastolic dysfunction, cardiac chambers have normal dimension and normal contraction, but decreased filling
With systolic dysfunction, what happens to the cardiac chambers and contraction?
They are dilated and contraction is abnormal. LVEF is less than 40%
With diastolic dysfunction, what happens to the cardiac chambers and contraction?
The cardiac chambers have relatively normal dimensions and normal contractile function but have stiff and noncompliant walls so there is increased filling pressure (LVEDP is increased)
What are the 3 most common causes of diastolic heart failure?
- hypertension
- ischemic heart disease
- hypertrophic cardiomyopathy
Both systolic and diastolic dysfunction show a decrease in ____________ leading to _________________.
Stroke volume - this leads to activation of SNS
How do systolic and diastolic dysfunction in HF differ in:
- EF
- Heart size
- common etiology
Systolic dysfunction:
- EF40
- normal
- hypertension, ischemic heart disease, hypertrophic cardiomyopathy
The most effective therapies for treatment of heart failure are those that ______________.
Interrupt the adverse neurohumoral activation
What are the AMA stages of heart failure?
A- high risk, but no structural/functional heart changes or symptoms
B- structural heart disease without symptoms
C- structural heart disease with prior or current symptoms
D- refractory HF requiring specialized intervention
What is the therapy for someone with Stage A heart failure?
- Lifestyle modification- smoking cessation, treat lipid disorder, regular exercise, diet modification, reduce alcohol/drugs
- ACEI in diabetics
What is therapy for someone with Stage B HF?
They have structural/functional changes but no symptoms.
- Lifestyle
- ACEI in diabetics
- BB in CAD/angina
What is therapy for someone with stage C HF?
Structural/functional heart changes with prior or current symptoms.
- lifestyle
- Diuretics
- ACEI or ARB
- BB
- Device therapy if at risk for arrhythmia