Assessment of Cardiac Function- Exam 1 Flashcards
3 layers of the heart muscle
Endocardium, myocardium, epicardium
4 chambers of the heart
R atrium and ventricle, L atrium and ventricle
2 atrioventricular valves
tricuspid and mitral
2 semilunar valves
aortic and pulmonic
What is the primary pacemaker for the myocardium?
sinoatrial node
What is the secondary pacemaker of the heart?
atrioventricular node
What kind of cells are the SA and AV node made of?
nodal cells
Electrical activation of cell caused by influx of sodium and potassium exits cell
depolarization
Return of cell to resting state caused by reentry of K+ into cell while NA+ exits
Repolarization
2 types of refractory periods
effective/absolute refractory period
relative refractory period
3 parts of a Cardiac Action Potential
Depolarization
Repolarization
Refractory Periods
Type of refractory period that describes the phase in which cells are incapable of depolarizing
effective/absolute refractory period
Type of refractory period describing the phase in which cells require stronger-than-normal stimulus to depolarize
Relative refractory period
Phase 1 of the Cardiac Action Potential Cycle
Rapid repolarization
Phase 0 of the Cardiac Action Potential Cycle
Rapid depolarization
Phase 3 of the Cardiac Action Potential Cycle
Final repolarization
Phase 4 of the Cardiac Action Potential Cycle
Resting
Refers to the events that occur in the heart from the beginning of one heartbeat to the next
cardiac cycle
The number of cardiac cycles depends on what?
heart rate
Each cardiac cycle has what 3 major sequential events?
Diastole
Atrial systole
Ventricular systole
Percent of end diastolic volume ejected with each heart beat (L ventricle)
ejection fraction
The ejection fraction refers to what chamber of the heart?
left ventricle
The amount of blood pumped by ventricle in L/min
cardiac output
Equation for Cardiac Output
CO = SV x HR
The amount of blood ejected with each heartbeat
Stroke volume
The degree of stretch of cardiac muscle fibers at end of diastole
Preload
The resistance to ejection of blood from ventricle
Aferload
The ability of cardiac muscle to shorten in response to electrical impulse
Contractility
3 parts of stroke volume
Preload
Afterload
Contractility
What are the influencing factors of cardiac output?
Control of heart rate
Control of stroke volume
What systems control heart rate?
Autonomic nervous system
Baroreceptors
The Frank-Starling Law refers to controlling what part of the stroke volume?
Preload
What specifically affects the control of the afterload?
Affected by systemic vascular resistance, pulmonary vascular resistance
Contractility is increased by what?
Catecholamines, SNS, and certain medications
Increased contractility results in increased ?
stroke volume
Decreased contractility is caused by ?
Hypoxemia, acidosis, and certain medications
Which of the following best defines stroke volume?
a. the amount blood ejected with each heartbeat
b. amount of blood pumped by the ventricle in liters per min
c. degree of stretch of the cardiac muscle fibers at the end of diastole
d. ability of the cardiac muscle to shorten in response to an electrical impulse
a. the amount of blood ejected with each heartbeat
What information do you want to collect as the nurse assessing the cardiovascular system?
-health hx, demos, family/genetic hx, cultural/social factors, risk factors
2 types of risk factors in cardiac health
modifiable
nonmodifiable
Common symptoms associated with cardiac health
Chest pain/discomfort
Pain/discomfort in other areas of the body
SOB/dyspnea
Peripheral edema
Weight gain
Abdominal distention
Palpitations
Unusual fatigue
Dizziness
Syncope
Change in LOC
What is assessed during the physical assessment portion of the cardiac assessment?
(how many times can you say assess in one sentence?)
General appearance
Skin/extremities
Pulses
BP and orthostatic changes
Jugular vein pulses
Heart inspection, palpation, auscultation