CV + Lymph Flashcards
The tricuspid valve prevents the back flow of blood between which chambers of the heart?
Right atrium and right ventricle
The bicuspid valve prevents the back flow of blood between which chambers of the heart?
Left atrium & left ventricle
What is the purpose of the semilunar valves?
Prevent the back flow of blood between the aorta/pulmonary artery and the left and right ventricles respectively
Differentiate systole & diastole
Systole: ventricular contraction
Diastole: ventricular relaxation
What is end-systolic volume? What is its typical value?
Volume of blood remaining in the ventricles after ventricular contraction; ~50 mL
What is end-diastolic volume? What is its typical value?
Volume of blood remaining in the ventricles after diastole; ~120 mL
What is the atria kick? When does it occur & what is its purpose?
The atrial kick is the atrial contraction that occurs during the last 1/3 of diastole; completes ventricular filling; adds last 20-30% of end-diastolic volume
The right coronary artery supplies what structures of the heart?
- Right atrium
- Most of right ventricle
- inferior wall of L ventricle
- AV Node
- Bundle of His
- SA Node (60% of time)
The left coronary artery supplies what structures?
- Two divisions: LAD, Circumflex
- LAD: left ventricle, interventricular septum, inferior areas of apex
- Circumflex: lateral & inferior walls of L ventricle, portion of L atrium, SA node 40% of time
The SA node initiates an impulse at a rate of what? Which divisions of the nervous system can affect this?
60-100 beats per minute
Both sympathetic & parasympathetic innervations present
The AV node has an intrinsic firing rate of what?
40-60 beats per minute
Injury at what level of the spinal cord would impact a patient’s ability to reach their age-adjusted max heart rate?
T1-T4 and above
The purkinje fibers have an intrinsic firing rate of what?
20-40 beats per minute
Define stroke volume and the typical value in an adult
Amount of blood ejected with each contraction; 55-100 mL/beat
Stroke volume is influenced by what 3 factors?
- Contractility
- Pre-load
- After-load
The Frank-Starling Law refers to what?
The greater the pre-load, the greater the stroke volume
What is the typical cardiac output for a healthy adult at rest? How is this determined?
4-5 L/minute; HR x stroke volume
What is normal left ventricular end-diastolic pressure?
Pressure in the left ventricle during diastole; 5-12 mmHg
What is the ejection fraction? What is it’s typical value?
- % of blood emptied from ventricle during systole; clinically useful measure of L heart function
- stroke volume/left ventricular end diastolic volume
- Average > 55%
What ejection fraction indicates a patient in heart failure?
< 40%
What is the rate pressure product? How is it calculated?
RPP= measure of myocardial oxygen demand aka how much stress is on the heart muscle itself
Heart rate x systolic blood pressure
Normal RPP should not be > 10,000
Where is the primary site for vascular resistance?
Arterioles
What factors influence venous circulation?
- Muscle contraction (aka muscle pump)
- Gravity
- Respiration (increases venous return w/ inspiration)
- compliancy of R side of heart
Lymph fluid travels through the lymphatic system to eventually reach what structure where it is dumped back into circulation?
Left subclavian vein
True or false: Abdominal and thoracic cavity pressure does not change with normal breathing.
False
Major lymph nodes include what?
- Submaxillary, cervical, axillary, mesenteric, iliac, inguinal, popliteal, cubital
[Sccampii]
Discuss the parasympathetic pathway that influences the cardiac system
- Control center: medulla, cardioinhibitory center
- vagus nerve/cardiac plexus releases aCh at SA/AV node, myocardium (sparsely)
- Decreases: HR, contraction force, restricts coronary arteries
Discuss the sympathetic pathway that influences the cardiac system
- Control center: medulla, cardioaccelatory center
- T1-T4, upper thoracic-superior cervical chain ganglia: release epinephrine/NE at SA/AV node, conduction pathways, & myocytes
- Increases HR, contraction force, cardiac metabolism, coronary vasodilation
An increase in right atrial pressure will typically result in what?
Reflex acceleration of heart rate
What are the main mechanisms of controlling heart rate? (4)
- Baroreceptors sensing pressure –> triggers either a sympathetic or parasympathetic response
- Chemoreceptors –> high CO2, low pH trigger increase in HR; increased O2 triggers decrease in HR
- Body temp –> increase BT = increase HR; lower BT = lower HR
- Ion concentrations
Hyperkalemia can result in what consequences for cardiac function?
Decreased HR & contractility
ECG: widened PR interval & QRS; tall T-waves
Hypokalemia can result in what consequences for cardiac function?
ECG: flat T-wave, prolonged PR & QT intervals
arrhythmias, ventricular fibrillation
Hypercalcemia can result in what consequences for cardiac function?
increased heart actions
Hypocalcemia can result in what consequences for cardiac function?
Depressed heart actions
Hypermagnesemia can result in what consequences for cardiac function?
arrhythmia or cardiac arrest
Hypomegnesemia can result in what consequences for cardiac function?
coronary artery vasospasm, sudden death
What specific cardiovascular signs/symptoms should be screened for during the patient interview?
- Chest pain
- Fatigue
- Palpitations
- Dizziness, syncope
- Edema
Discuss non-modifiable risk factors for cardiovascular disease
- Age: Men > 45, women > 55
- Family history
- Race: African American
- Gender: men > risk than pre-menopausal women; after menopause risk equalizes
Discuss modifiable risk factors for cardiovascular disease
- Cholesterol (total < 200 mg/dL; LDL < 160; HDL > 40)
- Diabetes: A1C < 7%
- Diet: low fat, low sodium, balanced
- Hypertension
- Obesity
- Physical inactivity (30 min +/day/5-6x/wk)
- Tobacco
What are considered appropriate values for cholesterol? Total? LDLs? HDLs? Triglycerides?
Total < 200 mg/dL
LDL < 160
HDL > 40
Triglycerides < 150 mg/dL
Cyanosis, pallor, and diaphoresis are all potential signs of what?
decreased cardiac output, and low oxygen saturation
What pulse is best when examining infants?
brachial pulse
Describe the grading scale for peripheral pulses
0= absent
1+= diminished
2+= easily palpable
3+=full pulse
4+= bounding
What are the typical heart rate ranges for adults, children, and newborns?
Adult/teen= 60-100 bpm
Children 60-140 bpm
Newborns= 90-164 bpm, avg, 127
Postural tachycardia syndrome is defined as
Sustained HR increase ≥ 30 beats per minute w/in 10 minutes of standing
Irregular pulse may be associated with what condition(s)?
arrhythmia, myocarditis
Weak, thready pulse may be associated with what condition(s)?
low stroke volume, cardiogenic shock
Bounding, full pulse may be associated with what condition(s)?
shortened ventricular systole, decreased peripheral pressure, aortic insufficiency
Auscultation landmark: aortic valve
2nd right intercostal space @ sternal border
Auscultation landmark: pulmonary valve
2nd left intercostal space @ sternal border
Auscultation landmark: tricuspid valve
4th left intercostal space @ sternal border
Auscultation landmark: mitral valve
5th left intercostal space @ mid clavicle area
S1 heart sound indicates what?
- Normal
- Closure of mitral/tricuspid valves
- Marks beginning of systole
- Decreased in 1st degree heart block
S2 heart sound indicates what?
- Normal
- Closure of aortic/pulmonary valves
- Marks end of systole
- Decreased in aortic stenosis
A systolic murmur falls between what heart sounds? What might it indicate?
- Between S1 & S2
- Valvular disease or may be normal
A diastolic murmur falls between what heart sounds? What does it indicate?
- Between S2 and S1
- Usually indicates valvular disease
Discuss the following terms related to heart sounds:
Thrill
Bruit
Gallop rhythm
- Thrill: abnormal tremor accompanying a vascular or cardiac murmur, felt on palpation
- Bruit: adventitious sound (blowing sound); common in carotid/femoral arteries; indicates atherosclerosis
Discuss a gallop rhythm
- Abnormal rhythm with three sounds in each cycle
- S3: associated w/ ventricular filling; may indicate CHF
- S4: associated w/ ventricular filling & atrial contraction; indicative of pathology e.g. CAD, MI, aortic stenos, or chronic hypertension
Discuss the following ECG segments & what event they are linked to:
P wave
PR interval
QRS wave
ST segment
T wave
QT interval
P wave: atrial depolarization
PR interval: impulse traveling from atria —> purkinje fibers
QRS complex: ventricular depolarization
ST segment: beginning of ventricular repolarization
T wave: ventricular repolarization
QT interval: time for electrical systole
How do you calculate heart rate from an ECG, assuming a normal rhythm?
count interval between QRS complex on 6 second strip and multiply by 10
Ventricular arrhythmias often result from what?
ectopic cells in the ventricles affecting rhythm; these cells are outside of the normal conduction system
Atrial arrhythmias often result from what?
ectopic foci in the atria outside of the SA node
Discuss heart blocks
Abnormal delays or failure to conduct through normal conducting system
Recognition of which heart block would negate a medical emergency?
Third-degree
When would a PVC indicate the potential for a medical emergency?
> 6 per minute
Metabolic & drug influences on ECG: Hyper & hypokalemia
Hyperkalemia: widen QRS, flatten p wave, peak T wave
Hypokalemia: flattens T wave (or inverts), produces U wave
Metabolic & drug influences on ECG: Hyper & hypocalcemia
Hypercalcemia: widens QRS, shortens QT interval
Hypocalcemia: prolongs QT interval
Metabolic & drug influences on ECG: Hypothermia
elevates ST segment, slows rhythm
Review BP normative values for adults
Review BP normative values for peds
Discuss Mean Arterial Pressure (MAP)
- Arterial pressure in large arteries over time
- Dependent upon avg blood flow & arterial compliance
- Important clinical measure in critical care
- Normal: 70-110 mmHg
- < 50 = hypotension
Review normal respiration rates:
Adult
Child
Newborn
Adult: 12-20 bpm
Child: 20-30 bpm
Newborn: 30-40 bpm
Define paroxysmal nocturnal dyspnea
Sudden inability to breath occurring during sleep; result of LV failure causing pulmonary congestion
Adventitious lung sounds: crackles (rales)
Rattling, bubbling sounds
May be d/t secretions in lungs
Adventitious lung sounds: Wheezes (ronchi)
Whistling sounds
d/t: pneumonia, bronchitis, COPD
Normal SpO2 levels vs. hypoxic SpO2 levels
Normal: 98%-100%
Hypoxemia: <90%
Cardiac-associated pain in women is most likely to present in what pattern?
Indigestion, gas-like pain, dizziness, nausea, unexplained weakness/fatigue, pain between shoulder blades, sense of impending doom