15. Heart Failure Flashcards
Define heart failure
Inability of heart to supply blood to tissues sufficient to meet their metabolic needs, or achieved at the expense of elevated filling pressures
Simply put what is heart failure?
Inability of the heart to keep up with demand
Leads to inadequate perfusion of organs
List the different types of heart failure
Left vs Right
Chronic vs Acute
HFrEF vs HFpEF
Describe left heart failure
Dysfunction associated with left ventricle
Ejection or filling issue
Blood backs up into the lungs causing congestion, increases pressure in lungs, hydrostatic pressure increased, fluid leaks into 3rd space, causes respiratory symptoms
(Breathlessness, coughing, dizziness)
Describe right heart failure
Dysfunction associated with the right ventricle
Ejection or filling issue
Increased afterload of the pulmonary circulation (pulmonary hypertension) means Right ventricle has to contract with more force, cardiac myocytes need more O2 which they don’t have. Causes cell death
Often secondary to left heart failure
Describe chronic heart failure
Slow onset
Infection, pulmonary embolism, myocardial infarction or surgery
Describe acute heart failure
Rapid onset
Symptoms similar to chronic HF, except the timing of onset and worsening is much more severe
Describe heart failure with reduced ejection fraction (HFrEF)
Abnormal systolic function: left ventricle unable to pump blood into aorta
Impaired contraction of the ventricles which despite an increase in HR results in decreased cardiac output
Typically, weakness is caused by damage or destruction of the ventricular myocytes
Weaker ejection leads to higher diastolic pressures
Describe EDV, SV and EF in HFrEF
EDV remains high/ increases
SV decreases
EF decreases
Describe heart failure with preserved ejection fraction (HFpEF)
Abnormal diastolic function
Normal contraction of the ventricle
Increased stiffness of ventricle, impaired relaxation or impaired filling
the reduced stroke volume is masked when looking at ejection fraction
Describe EDV, SV and EF in HFpEF
EDV inherently reduced (less space for blood to fill ventricles)
SV decreases (but is masked in EF because EDV also decreases)
EF stays normal/ mild reduces
Incidence of heart failure through ages
Increases >60
Peaks between 75-84
Then decreases
List 6 causes of heart failure
Valve disease (hardening of valve reduces ventricular filling or ejection)
Ischaemic Heart Disease (IHD) (narrowing of coronary arteries, causes ischaemia in myocytes)
Myocardial Infarction (significant occlusion in coronary artery, causes death of myocytes)
Hypertension (increases after load, decreased CO)
Dilated cardiomyopathy (dilated LV, reduces generable pressures, can’t eject blood out)
Hypertrophic cardiomyopathy (increased LV thickness, reduces internal volume, impedes filling)
Describe coronary artery disease (Ischaemic Heart Disease)
Occlusion of coronary arteries Less O2 to myocytes Myocytes die Less heart to perform same function Need more O2 (which they don’t have)
List 3 presenting features of a patient with heart failure
Fatigue
Exertional breathlessness
Weight loss
List 4 clinical features of a patient with heart failure
Tachycardia
Pitting oedema
Increased jugular venous pressure (JVP)
Ascites
Why is raised jugular venous pressure a hallmark sign of heart failure?
Increased pressure in right side of heart leads to pressures backing up into systemic veins, especially visible in jugular vein.
What is pitting oedema? (a hallmark sign of heart failure)
Fluid accumulation in tissue (especially of lower extremities) leads to a pitting effect when physically depressed.
The indentation is visible for a short period
Why is ascites a hallmark sign of heart failure?
Fluid accumulation in peritoneal cavity due to rise in hydrostatic pressure and fluid leakage into 3rd space
Causes increase in size of abdomen
When and where is B-type natriuretic peptide (BNP) released?
from ventricular myocytes in response to stretch
What BNP ranges for under and over 70s is suggestive of heart failure?
Under 70: >100pg/mL
Over 70: >300ph/mL
What is the action of BNP?
Reduces blood pressure: Vasodilation of micro-vessels (reduction in afterload, ventricles don’t have to work so hard) Reduced aldosterone secretion Reduced sodium reabsorption Inhibits renin secretion
What lifestyle changes are suggested to treat heart failure?
Weight loss
Stop smoking
Exercise
Less alcohol
What are the 2 first line drugs used to treat heart failure?
ACE inhibitors: block aldosterone production
Beta blockers: Slow HR, Heart requires less energy and O2
Why are diuretics used to treat heart failure? Give an example
Remove excess fluid
Decrease pressure
Afterload decreases
E.g. Spironolacetone
Describe the ‘donkey’ analogy of treatment for heart failure
Diuretics and ACE inhibitors reduce the load
Beta-blockers reduce the speed, which saves energy and makes it easier
Non pharmacological treatment for heart failure:
Fluid control
Haemofiltration
Peritoneal dialysis
Haemodialysis
Non pharmacological treatment for heart failure:
Devices
Intra-aortic balloon pumping
Resynchronisation
VAD/ Total artificial heart
Non pharmacological treatment for heart failure:
Surgical
Coronary artery bypass graft
Valve surgery
Transplantation
Considering the Law of LaPlace, how does compensatory hypertrophy effect cardiac function
Wall thickness increases
Wall stress decreases
Less space for blood to pool in ventricles
Considering the Law of LaPlace, how does dilated cardiomyopathy effect cardiac function
Wall thickness decreases
Wall stress increases
Heart unable to contract with enough force to eject blood
Describe the hormonal changes that occur in heart failure (when the heart is beating less effectively?
Reduced renal perfusion Activates RAAS Rise in aldosterone production Causes vasoconstriction Raises BP Increases sodium retention Increases water reabsorption
How is the nervous system involved in regulating BP?
Aldosterone and mechanoreceptors stimulate sympathetic nervous system
Increases release of ADH
Increases heart rate and contractility
Life of a person with heart failure
Breathless and tired
Heart is damaged and a less effective pump
QoL is poor
Life expectancy is reduced
Progression in heart failure
Generally from mild to moderate to severe
Sudden death is rare
What speeds up progression of heart failure?
Coronary events
