Test 2 AH Cardiac Flashcards
(104 cards)
How does blood flow through the heart?
- Vena Cava
- Right Atrium
- Tricuspid valve
- Right Ventricle
- Pulmonic valve
- Lungs
- Left Atrium
- Mitral valve
- Left Ventricle
- Aortic valve
- Systemic Circulation
Diastole
relaxation, blood fills ventricles
Systole
when the ventricles contract
Normal Cardiac Output
4-6 L/Min
Preload
- volume coming into the ventricle (end diastolic pressure)
- increased in hypervolemia
Frank Starling Law
as a larger volume of blood flows into the ventricle, the blood will stretch the walls of the heart, causing a greater expansion during diastole, which in turn increases the force of the contraction and thus the quantity of blood that is pumped into the aorta during systole.
Afterload
- resistance the left ventricle must overcome to circulate the blood
- increased in hypertension
Stroke Volume
amount of blood ejected by the left ventricle in one contraction (can be left or right)
Positive Inotropic Agents
- medicines that increase the force of your heart’s contractions
- digoxin, calcium, dopamine, epinephrine, norepinephrine
Negative Inotropic
- weaken the force of the heartbeat
- Acetylcholine from Vagus nerve
P Wave
- atrial depolarization
- ## SA Node Initiates this
QRS
- Ventricles contract
- 0.04
QT
- repolarization (recovery)
- 0.42
Cardiac Output
- the amount of blood pumped by each ventricle in 1 minute (normal 4-8 L/min)
- CO = HR x Stroke Volume
Cardiac Index
- Cardiac Output/Body Surface Area
- Normal is 2.8-4.2 L/min/m2)
Sympathetic Nervous System: Effects on the Heart
increases heart rate by the beta adrenergic receptors
Peripheral Nervous System: Effects on the Heart
decreases heart rate by the vagus nerve
Sympathetic Nervous System: Effect on Blood Vessels
increases vasoconstriction by a1-adrenergic receptors, decreases vasodilation by a1-adrenergic receptors
Baroreceptors
sensitive to stretch or pressure with the arterial system (aortic arch and carotid sinus) Fast response in changes in blood pressure
Chemoreceptors
capable of causing changes in respiratory rate and BP in response of increased CO2 (aortic/carotid bodies and medulla)
Cardiovascular Disease Risk Factors
- elevated BP
- diabetes
- obesity
- smoking
- nutrition
- sedentary lifestyle
- family history
- adverse lipid profile
Hypertension
- may need to measure both arms
- often symptom free
- typically the primary disease
Hypertension: Patient Evaluation
- two consecutive blood pressure measurements over 2 weeks
- assess lifestyle and identify other CV risk factors
- reveal identifiable causes of high BP
- Assess the presence of absence of target organ damage and CVD
Values: Mild Hypertension
140/90