Heart Failure Flashcards
What does chronotropy mean?
Heart rate
What is vascular resistance/peripheral resistance?
Squeeze of blood vessels outside the heart resisting blood flow
What is Cardiac Output (CO) a measure of?
How much blood is pumped out of the left ventricle in 1 minute
What is Stroke Volume (SV) a measure of?
The volume of the blood ejected with each beat of the heart
Define: Ionotropy
Contractility
Define: Preload
Filling of ventricles and stretch of walls (dealing with the tension applied to the ventricular walls)
Stretch (IN)
What happens if we increase preload?
The tension on the walls increase which causes oxygen demand to increase as well.
Define: Afterload
The amount of pressure that is acting on the heart.
Squeeze (OUT)
Describe how low and high after loads affect the blood’s travels.
Low afterload: easy for blood to exit the heart
High afterload: hard for blood to exit the heart
What is stroke volume affected by?
Contractility (ionotropy)
Afterload (squeeze/resistance)
Preload (stretch/filling)
If stroke volume increases, cardiac output (CO) ______.
Increases
How would you increase stroke volume?
Increase contractility
Increase preload
Decrease afterload
How would you decrease stroke volume?
Decrease contractility
Decrease preload
Increase afterload
LVEDV (preload)
Left ventricular end diastolic volume (The volume at the end of rest-so when it is filling).
What two ways can heart failure occur?
- MI (myocardial infarction) - heart dies! One lane of blood traffic is shut down.
- High blood pressure acts as a traffic jam for blood
**Both of these things cause a decrease in stroke volume.
What 4 things can be done to compensate for heart failure?
- Increase heart rate
- Increase amount of blood (increases preload - RAAS)
- Redirect blood to heart (vasoconstriction of blood vessels, endothelin, RAAS, SNS)
- Construct more lanes (Ventricular hypertrophy & remodelling)
What are the pros and cons of:
1. increase heart rate
Pro:
Helps maintain cardiac output
Con:
short filling time, increase BP, increase oxygen demand, risk of arrhythmias, puts stress on the heart
What are the pros and cons of:
2. increase amount of blood
Pro:
Increase stroke volume (more stretch, more preload)
Con:
Pulmonary and or peripheral edema, increased oxygen demand, water retention
What are the pros and cons of:
3. redirect blood to the heart
Pro:
Helps maintain blood pressure, recruits blood to heart and brain.
Con: Increased afterload (resistance) which decreases stroke volume
What are the pros and cons of:
4. ventricular hypertrophy & remodelling
Pro:
Helps to maintain CO, decreases oxygen demand
Con:
Increased risk of ischemia, dysfunction, fibrosis and arrhythmias, ventricle becomes smaller
Describe natuiretic hormones and how they cause vasoconstriction.
- causes an increase in intracellular sodium and calcium (bad)
- inhibits the cellular Na/K ATPase (sodium builds up in the cell and it becomes more excitable and causes our vessels to constrict)
Describe natuiretic peptides and how they cause vasodilation.
- secreted by the brain and atria to try and counteract negative compensatory mechanisms in heart failure (good)
- promote water loss (diuresis which causes vasodilation) to decrease total peripheral resistance (TPR)
What is the difference between left and right sided heart failure?
Right-sided HF:
- right side is failing
- blood backed up in abdominal organs and periphery
Left-sided HF:
- left side is failing
- blood backed up in lungs
List some symptoms of heart failure.
Fluid retention and edema:
- rales (crackling sound upon auscultation with stethoscope)
- rapid weight gain
- pitting edema (squishy feet and ankles)
- elevated jugular venous pressure (JVP)
Shortness of Breath:
- orthopnea - difficulty breathing when lying down
- cough
- dyspnea - difficult breathing
Fatigue (especially with activity)
Confusion
Cyanosis (oxgen depletion) - blue lips, fingers or toes
