Module 6 - Chronic Cardiovascular Illness Flashcards
What are the 4 chambers of the heart?
Right and Left Atria // Right and Left Ventricles
What are the 2 types of heart valves?
Atrioventricular (tricuspid and mitral) and semilunar valves.
How can an aortic aneurysm cause a myocardial infarction?
A bulge of blood in the aorta can cause an MI by blocking blood flow
How can a coronary artery dissection cause a myocardial infarction?
Spontaneous tearing of the arterial wall can cause MI when fluid builds up between layers of the heart, preventing blood flow.
Starting with the vena cava, what is the pathway for blood?
Vena cavae –> right atrium –> tricuspid valve –> right ventricle –> pulmonary semilunar valve –> pulmonary arteries –> lungs –> pulmonary veins –> left atrium –> mitral valve –> left ventricle –> aortic semilunar valve –> aorta –> systemic circulation
What is the purpose of the SA node?
Initiate heartbeat and synchronize atrial and ventricular contractions
What is the purpose of the AV nodes?
To delay the signal from the SA node to allow the ventricles to fully fill and prevent atria and ventricles from contracting at the same time
What is the purpose of the bundle of His?
Rapid conduction of the signal to the ventricles
What is the purpose of the Purkinje fibres?
Rapid transmission of the signal through the ventricles, allowing them to contract simultaneously
How do we represent the electrical activity of the heart to determine any problems?
ECG
How do parasympathetic neurotransmitters affect heart rate and blood pressure?
Tend to lower heart rate and blood pressure (vasodilation)
How do sympathetic neurotransmitters affect heart rate and blood pressure?
Tend to increase heart rate and blood pressure (vasoconstriction)
What effect does the renin-angiotensin-aldosterone system have on blood pressure?
Work to increase BP
How do ACE inhibitors lower blood pressure?
They inhibit angiotensin converting enzyme from the lungs and prevent it from converting angiotensin I to angiotensin II. Angiotensin I is not active, therefore cannot increase blood pressure.
What is considered normal heart rate?
60-100 bpm
What is the danger of a slow heart rate?
Stasis and clots forming as blood does not move as quickly through the body
What is the danger of a high heart rate?
Can lead to fatigue that can eventually cause slowing of the heart rate
What does systolic blood pressure represent?
Contraction of the ventricles, opening of the semilunar valves to eject blood
What does diastolic blood pressure represent?
Relaxation of the ventricles, opening of the mitral valve to fill vents
What factors can increase systemic vascular resistance?
- smaller blood vessel diameter
- longer blood vessels
- increased blood viscosity
What is the formula for measuring systemic vascular resistance?
SVR = (MAP - CVP) / CO
MAP = mean arterial pressure
CVP = central venous pressure
What is stroke volume?
The amount of blood ejected by the left ventricle with each contraction, measured in mL
What factors can influence stroke volume?
Heart rate, contractility, preload
What is preload?
The initial stretching of cardiac myocytes before contraction, which depends on ventricular filling
How does increasing preload impact cardiac output?
Will increase cardiac output
Why would we give vasopressers to a patient experiencing hypovolemic shock?
To cause vasoconstriction, which increases the volume of blood during the filling phase (preload)
Would we give nitroglycerin to increase or decrease preload?
Decrease bc it causes vasodilation, which decreases venous return to the heart
What is afterload?
The pressure the heart must work against to eject blood –> resistance that needs to be overcome during contraction
What can increase afterload?
pulmonary HTN, valve issues
What can decrease afterload?
Drugs that decrease vascular resistance
What can happen if we have altered contractility in the heart?
Heart failure
What is cardiac output?
The amount of blood pumped out by each ventricle in one minute.
What formula do we use to measure cardiac output?
CO = HR x Stroke Volume
What does a blood pressure monitor tell us about hemodynamics?
Cardiac output and conditions of the vasculature
What does a pulse oximeter tell us about hemodynamics?
How efficiently the heart is pumping blood/oxygen to the rest of the body
What are 4 hemodynamic disorders?
1) hypertension –> can impair cardiovascular function
2) shock –> inadequate blood flow to organs
3) heart failure –> heart unable to pump enough blood to meet body needs
4) atherosclerosis –> plaques build up in blood vessels, reducing blood flow