Cardiac system and Hyertension (Week 1) Flashcards
Where is the heart located anatomically?
the mediastinal space of the thoracic cavity
Where is the beating of the heart best felt?
The 5th intercostal space
Point of maximal impulse (PMI)
The point where the apex of the heart is closest to the chest wall. This is where you auscultate the apical pulse. The left ventricle is the closest chamber to this point.
The three layers of heart tissue
- Endocardium - Inner Lining
- Myocardium - Muscle tissue
- Epicardium - Fibrous outer layer
What is the heart surrounded by?
The pericardial sac (The fourth layer)
What is the function of the pericardial fluid?
Lubricates the space between the heart and the pericardial sac.
What is the septum?
Divides the left and the right sides of the heart.
Why are the walls of the ventricles thicker than that of the atria?
Because of the need for musculature to create blood pressure.
Afterload
The peripheral resistance against which the left ventricle must pump.
the force the heart must pump against
to push blood out of the LV. The greater the volume
(preload) the greater the pressure needed to expel it.
As afterload increases, stroke volume decreases.
Arterial Blood Pressure
A measure of the pressure exerted by blood against the walls of the arterial system.
Cardiac Index (CI)
A measure of the cardiac output of a patient per square meter of body surface area.
Cardiac Output (CO)
The total blood flow through the systemic or pulmonary circulation per minute; can be described as the stroke volume (amount of blood pumped out of the left ventricle per beat [~70 mL]) multiplied by the heart rate (HR) over 1 minute.
Cardiac Reserve
The ability to respond to physiological demands (exercise, stress, hypovolemia) by increasing or decreasing cardiac output as much as three-fold or four-fold.
Diastole
Relaxation of the myocardium.
Relaxation=filling
• Atria fill
• Ventricles fill
Diastolic Blood Pressure
The residual pressure of the arterial system during ventricular relaxation.
Ejection Fraction (EF)
The percentage of end-diastolic blood volume that is ejected during systole.
Mean Arterial Pressure (MAP)
A measurement related to BP; calculated by adding the diastolic pressure to one third of the pulse pressure.
Murmurs
Sounds produced by turbulent blood flow through the heart or the walls of large arteries.
Point of Maximal Impulse (PMI)
The site on the chest wall at the fifth intercostal space, at which the thrust or pulsation of the left ventricle is most prominent.
Preload
The volume of blood in the ventricles at the end of diastole, before the next contraction.
The force used to stretch the muscle fibers
at end diastole, the heart’s maximum fill point.
Preload is determined by venous return (volume) and
fiber length and ability to stretch. The amount a
balloon stretches when inflated represents preload.
Pulse Pressure
The difference between the systolic and the diastolic pressures.
Systole
Contraction of the myocardium.
• Atrial systole blood ejects
into ventricles
• Ventricular systole blood
ejects from ventricles to
enter into:
• pulmonary artery
• aortaSystolic Blood Pressure
The peak pressure exerted against the arteries when the heart contracts.
baroreceptors
Specialized nerve cells, located in the carotid arteries and arch of the aorta, that are sensitive to stretching and, when stimulated by an increase in BP, send inhibitory impulses to the sympathetic vasomotor centre in the brainstem.
Blood Pressure
The force exerted by the blood against the walls of the blood vessel; must be adequate for tissue perfusion to be maintained during activity and rest.
Hypertension
Sustained elevation of blood pressure over more than one reading; in adults. Exists when systolic blood pressure (SBP) is equal to or greater than 140 mm Hg or diastolic blood pressure (DBP) is equal to or greater than 90 mm Hg.
Hypertensive crisis
A severe and abrupt elevation in blood pressure, arbitrarily defined as a diastolic blood pressure above 120 to 130 mm Hg.
Isolated Systolic Hypertension
A sustained elevation in systolic blood pressure equal to or greater than 160 mm Hg with a diastolic blood pressure less than 90 mm Hg.
Orthostatic Hypotension
A decrease of 20 mm Hg (or more) in systolic pressure or a decrease of 10 mm Hg (or more) in the diastolic pressure that occurs when an individual assumes a standing position.
Primary (Essential) Hypertension
Elevated blood pressure without an identified cause; accounts for about 90 to 95% of all cases of hypertension.
Secondary Hypertension
Hypertension for which there is a known cause; accounts for about 5 to 10% of all hypertension cases.
Systemic Vascular Resistance (SVR)
The force opposing the movement of blood within the blood vessels; the radius of the small arteries and arterioles is the principal factor determining vascular resistance.
Which of the following instructions given to a patient who is about to undergo Holter monitoring is most appropriate?
A) “You may remove the monitor only to shower or bathe.”
B) “You should connect the monitor whenever you feel symptoms.”
C) “You should refrain from exercising while wearing this monitor.”
D) “You will need to keep a diary of all your activities and symptoms.”
“You will need to keep a diary of all your activities and symptoms.”
A Holter monitor is worn for at least 24 hours while a patient continues with usual activity and keeps a diary of activities and symptoms. The patient should not take a bath or shower while wearing this monitor.
The nurse is admitting a patient who is scheduled to undergo a cardiac catheterization. Which of the following allergies is most important for the nurse to assess before this procedure? A. Iron B. Iodine C. Aspirin D. Penicillin
Iodine
The physician usually will use an iodine-based contrast to perform this procedure. Therefore it is imperative to know whether or not the patient is allergic to iodine or shellfish
The blood pressure of a 71-year-old patient admitted with pneumonia is 160/70 mm Hg. Which of the following is an age-related change that contributes to this finding?
A. Stenosis of the heart valves
B. Decreased adrenergic sensitivity
C. Increased parasympathetic activity
D. Loss of elasticity in arterial vessels
Loss of elasticity in arterial vessels
An age-related change that increases the risk of systolic hypertension is a loss of elasticity in the arterial walls. Because of the increasing resistance to flow, pressure is increased within the blood vessel and hypertension results
The nurse is providing care for a patient who has decreased cardiac output related to heart failure. The nurse recognizes that cardiac output is
A. calculated by multiplying the patient’s stroke volume by the heart rate.
B. the average amount of blood ejected during one complete cardiac cycle.
C. determined by measuring the electrical activity of the heart and the patient’s heart rate.
D. the patient’s average resting heart rate multiplied by the patient’s mean arterial blood pressure.
calculated by multiplying the patient’s stroke volume by the heart rate.
Cardiac output is determined by multiplying the patient’s stroke volume (SV) by heart rate (HR), thus identifying how much blood is pumped by the heart over a one-minute period. Electrical activity of the heart and blood pressure are not direct components of cardiac output.
Auscultation of a patient’s heart reveals the presence of a murmur. This assessment finding is a result of
A. increased viscosity of the patient’s blood.
B. turbulent blood flow across a heart valve.
C. friction between the heart and the myocardium.
D. a deficit in heart conductivity that impairs normal contractility.
Turbulent blood flow across a heart valve.
Turbulent blood flow across the affected valve results in a murmur. A murmur is not a direct result of variances in blood viscosity, conductivity, or friction between the heart and myocardium.
While assessing the cardiovascular status of a patient, the nurse performs auscultation. Which of the following practices should the nurse implement into the assessment during auscultation?
A. Position the patient supine.
B. Ask the patient to hold his or her breath.
C. Palpate the radial pulse while auscultating the apical pulse.
D. Use the bell of the stethoscope when auscultating S1 and S2.
Palpate the radial pulse while auscultating the apical pulse.
In order to detect a pulse deficit, simultaneously palpate the radial pulse when auscultating the apical area. The diaphragm is more appropriate than the bell when auscultating S1 and S2. A sitting or side-lying position is most appropriate for cardiac auscultation. It is not necessary to ask the patient to hold his or her breath during cardiac auscultation.
A 59-year-old man has presented to the emergency department with chest pain. Which of the following components of his subsequent blood work is most clearly indicative of a myocardial infarction (MI)? A. CK-MB B. Troponin C. Myoglobin D. C-reactive protein
Troponin
Troponin is the biomarker of choice in the diagnosis of myocardial infarction (MI), with sensitivity and specificity that exceed those of CK-MB and myoglobin. CRP levels are not used to diagnose acute MI.
A nurse is caring for a patient immediately following a transesophageal echocardiogram (TEE). Which of the following assessments are appropriate for this patient? (Select all that apply.)
A. Assess for return of gag reflex.
B. Assess groin for hematoma or bleeding.
C. Monitor vital signs and oxygen saturation.
D. Position patient supine with head of bed flat.
E. Assess lower extremities for circulatory compromise.
Assess for return of gag reflex.
The patient undergoing a TEE has been given conscious sedation and has had the throat numbed with a local anaesthetic spray, thus eliminating the gag reflex until the effects wear off. Therefore it is imperative that the nurse assess for gag reflex return before allowing the patient to eat or drink. Vital signs and oxygen saturation are also important assessment parameters resulting from the use of sedation. A TEE does not involve invasive procedures of the circulatory blood vessels. Therefore it is not necessary to monitor the patient’s groin or lower extremities in relation to this procedure.
Which of the following cardiovascular effects of aging should the nurse anticipate when providing care for older adults? (Select all that apply.)
A. Arterial stiffening
B. Increased blood pressure
C. Increased maximal heart rate
D. Decreased maximal heart rate
E. Increased recovery time from activity
A. Arterial stiffening
B. Increased blood pressure
D. Decreased maximal heart rate
E. Increased recovery time from activity
Well-documented cardiovascular effects of the aging process include arterial stiffening, possible increased blood pressure, and an increased amount of time that is required for recovery from activity. Maximal heart rate tends to decrease rather than increase with age.
Cardiac Valves
Tricuspid
Pulmonic
Mitral
Atrial
Chordae Tendonae
Strands of fibrous tissue that anchor the cusps of the mitral and tricuspid valves into the papillary muscles of the ventricles. This prevents eversion of the leaflets into the atria during ventricular contraction.
Semilunar valves
Pulmonic and aortic valves
What do the semilunar valves do
Prevent blood from regurgitating into the ventricles at the end of each ventricular contraction.
Order of Blood flow through the heart
- Right Atrium from vena cava and coronary sinus
- Through Tricuspid Valve into right ventricle
- Pulmonic Valve into pulmonary artery
- Left atrium from the pulmonary veins
- Mitral Valve
- Left Ventricle
- Aorta
Stroke Volume
amount of blood pumped out of the LV
with each beat, depends on preload, afterload, and
contractility
