CVD - Chronic heart failure Flashcards
What is Chronic Heart Failure (CHF)
Syndrome of the inability of the heart to deliver adequate blood/oxygen to the body
What are the different heart failure (HF) - for each side
Left sided HF = failure to properly pump blood out to the body - systolic and diastolic failure
Right sided HF = back ups in the area that collects used blood
Congestive heart failure
Systolic HF is
Less blood pumped out of ventricles
Weakened heart muscle cant squeeze as well
Diastolic HF is
Less blood fills the ventricles
Stiff heart muscle cant relax normally
When does CHF occur
When heart is unable to pump sufficiently to maintain blood flow to meet body demands
What is affected by CHF
Reduced cardiac output - due to left/right ventricular dysfunction
Systolic dysfunction - due to impairment of left ventricle
Diastolic dysfunction - due to resistance to filling of one or both ventricles
Systolic dysfunction is when
The ventricles fill with blood and then can only pump out less than 40-50% of the blood
Diastolic dysfunction is when
The stiff ventricles fill with less blood
The ventricles then only can pump out 60% of the blood
What are the most common causes of CHF (3)
Conornary artery disease
Hypertension
Myocardial infarction
What causes systolic dysfunction (reduced ejection fraction)
Afterload
Impaired contractility
What is Afterload
What causes it
Chronic pressure overload
Advanced aortic stenosis
Uncontrolled severe hyptertension
What causes impaired contractility
Cononary artery disease
Chronic volume overload
Dilated cardiomyopathies
What causes diastolic dysfunction (preserved ejection fraction)
Impaired diastolic filling
Myocardial injury results in
Reduced cardiac output
Decreased carotid baroreceptor stimulation
Decreased renal perfusion
Reduced carotid BR stimulation and Renal perfusion results in
Activation of SNS and renin angiotensin aldosterone system (RAAS)
Activation of the SNS (from reduced carotid BR stimulation and Renal perfusion) results in
Increase HR and inotropy (contraction/force of muscle)
Myocardial toxicity
Activation of the RAAS results in
B type natriuretic peptides (BNP) released
A type natriuretic peptides (ANP) released
Vasconstriction - increases Afterload
Hemodynamic alterations - increases Preload
What causes vasoconstriction
Increased angiotensin 2
What causes hemodynamic alterations
Increased aldosterone
What does BNP and ANP both do
Decrease TPR and Central venous pressure
Where is BNP secreted and in response to what
By the ventricles in response to excessive stretching of cardiomyocytes
Where is ANP secreted and in response to what
By atria in response to high blood volume
What is the SNS then inhibited by
Which results in
Beta blockers
Negative remodeling
Worsened LV function
What is the RAAS inhibited by
ACE inhibitors
Angiotensin receptor blockers
Aldosterone antagonists
ADH antagonists
Negative remodeling and worsened LV function result in
Symptoms of HF
During exercise the neural pathway consists of
Arterial baroreceptors and skeletal muscle mechano receptors go brain
Brain creates sympathetic or parasympathetic to change HR and SV, also vasculature in muscle
Changes cardiac output
Changes in total vascular conductance
Resets BP
The rein angiotensin aldosterone system is made up of
Liver
Kidneys
Liver produces
Angiotensinogen
Kidney produces
Renin when there is a decrease in renal perfusion
Angiotensinogen and Renin create
Angiotensin 1
ACE is produced
On the surface of pulmonary and renal endothelium
Angiotensin 1 and ACE create
Angiotensin 2
Angiotensin 2 causes
Increase Sympathetic activity
Increase Tubular NA and CL reabsorption and K excretion = H2O retention
Stimulation of Adrenal gland cortex
Stimulation of arteriolar vasoconstriction - increases blood pressure
Stimulation of pituitary gland posterior lobe
All the stimulations of angiotensin cause what
Water and Salt retension
Effective circulating volume to increase
Perfusion of the juxtaglomerular apparatus to increase - inhibitatory signal to stop renin from being produced in kidney
What does the stimulation of the adrenal gland cortex cause
Aldosterone secretion
Which stimulates H2O retention
What does the stimulation of the pituitary gland posterior lobe cause
ADH secretion
Which stimulates H2O absorption in collecting duct
Regulation of stroke volume includes
EDV
Aortic blood pressure
Contractility of ventricles
What is EDV
End diastolic volume
Volume of blood in ventricles = preload
What is aortic blood pressure
Pressure that heart must pump against to eject blood = afterload
What enhances contractility
Circulating Epi and NeoEpi
Direct sympathetic stimulation of heart
Coronary artery disease (CAD) is a result of
Ischemic heart disease (IHD)
Build up of plaque in the coronary arteries
Risk factors
What is the most common cause of death
Coronary artery disease
What does the build up of plaque in coronary arteries cause
Leads to limited blood flow to the heart (ischemia)
Leads to heart attack (MI)
What are the risk factos of CAD
High LDL
Low HDL
Hypertension
Family history
Diabetes
Smoking
Obesity