Cardiopulmonary Flashcards

1
Q

Cardiac Output/Blood Flow Equation

A

HR x Stroke Volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What type of blood is found in fetal circulation?

A

Mixed Blood (both oxygenated and deoxygenated)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Fetal Circulation Anatomy

A

1) Ductus Venosus: shunts oxygenated blood from liver to inferior vena cava
2) Foramen Ovale: mixed blood travels from right to left atrium
3) Ductus Arteriosus: mixed blood shunted from pulmonary artery to aorta to send out to body
4) Umbilical Arteries: bring oxygenated blood back to placenta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Cardiac Muscle Anatomy/Physiology

A

1) Intercalated discs (increase closeness of fibers for transmitting excitation quickly)
2) Syncytial (“all or nothing” function, all fibers twitch at same time)
3) Larger T-tubules (propogate action potentials)
4) Calcium induced calcium release ( unique bc K+ drives skeletal muscle)
5) Less work required vs skeletal muscle
6) Twitches generate output
7) Never fatigues or rests

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Tissue Layers of Heart (Superficial to Deep)

A

1) Pericardium (fibrous layer)
2) Myocardium (contractile layer)
3) Endocardium (endothelial layer)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Landmarks for
1) Listening to HR
2) Apex location

A

1) Listening to HR: second intercostal space
2) Apex location: midclavicular line of 5th intercostal space

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Right vs Left Side of Heart

A

· Left Side: receives oxygenated blood from lungs and pumps to body
· Right Side: Receives deoxygenated blood from body and pumps to lungs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Systemic vs Pulmonary Circulation

A

· Systemic:
- delivers oxygenated blood to organs and muscles
- returns deoxygenated blood to heart
· Pulmonary:
- delivers deoxygenated blood to lungs
- returns oxygenated blood to heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Opening and Closing of Valves (passively)

A

· Open: upstream pressure > downstream
· Close: downstream pressure > upstream

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Chordae Tendinae Function

A

Provide tension for AV Valves (Tricuspid and Mitral) to prevent prolapse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Clinical Relevance of Heart Valve Sounds

A

·S1 (Lub): End of Diastole/ventricular filling
- Tricuspid and Mitral Valves close

·S2 (Dub): End of blood ejection
- Pulmonary and Aortic Valves close

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Cardiac Cycle Events

A

1) AV Valves Open (Diastole)
- ventricles fill
2) AV Valces Close (Systole)
- Isovolumetric Ventricular Contraction (all valves close)
3) Semilunar Valves Open (Systole)
- ventricular ejection
4) Semilunar Valves Close (Diastole)
- Isovolumetric Ventricular Relaxation (all valves closed)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Cardiac Performance Factors

A

1) Volume
2) Pressure
3) Flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Starling’s Law/ Length- Tension Relationship

A

↑ Volume (Preload/EDV) then ↑ Stretch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Contractility

A

· Intrinsic property of cardiac muscle and therefor NOT effected by volume or pressure
· Does effect preload/EDV
· Can change based on preload and what is needed to reach a certain SV
- ex: If contractility is ↓ then preload must be ↑ to achieve a certain SV
* Usually assumed as a constant measure but realistically functions to help balance what is needed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Hydrostatic Pressure

A

Change in Pressure relative to gravity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Transmural Pressure

A

· Difference in pressure between the inside and outside of a vessel
· Pressure must be greater inside > outside or else vessel would collapse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Type of relationship between cross-sectional area and velocity?

A

· Inverse relationship
· Ex: If ↑ CSA then ↓ Velocity (in capillaries)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Relationship between Flow and Driving Pressure, Radius, Viscosity, and Length

A

· Flow is directly proportional to driving pressure and radius but inversely proportional to viscosity and length
· Ex: ↑ Flow :
- ↑ Driving Pressure
- ↑ Radius
- ↓ Viscosity
- ↓ Length

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Is pressure greater in systemic or pulmonary circulation?

A

· Systemic (left side of heart) > Pulmonary (right side of heart)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Relationship between Resistance to Blood Flow and Radius

A

· Resistance is directly proportional to viscosity and length but inversely proportional to (fourth power) radius
· Ex: ↑ Resistance :
- ↑ Viscosity
- ↑ Length
- ↓ radius ^4
·

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

STEMI vs. NSTEMI

A

1) STEMI (ST Elevation Myocardial Infarction): transmural, full thickness ischemia
* Myocardial injury more severe usually

2) Non-ST Elevation Myocardial Infarction: subendocardial, partial ischemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What can happen during the super-normal refractory period?

A

Another impulse can cause ventricles to depolarize again

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What happens if QT Interval is greater than half the R-R Interval?

A

Another Heartbeat can happen before ventricles have repolarized which can lead to lethal arrhythmias

23
What part of the EKG would reflect damage to the atria conduction system?
P-wave
24
What dysfunction would a widened QRS complx represent?
His-Purkinje network
25
Normal Capillary Pressure Factors
Maintained when pre-capillary resistance> post-capillary resistance
26
How do you increase capillary pressure?
Decrease pre-capillary resistance which leads to more flow and thus an increase in pressure
27
· What happens to pre-capillary resistance during Arteriole Dilation (or venular constriciton) · Arteriole Constriction?
· Arteriole Dilation: ↓ Pre-capillary Resistance · Arteriole Constriction: ↑ pre-capillary resistance thus decreasing flow and decreasing pressure in the capillary
28
Distensibility
Describes the change in volume for a given change in pressure
29
Convection
· Capillary exchange of water · Dependent upon the balance of pressures between capillary and interstitial
30
Cardiac Action Potentials
· Na+ Current: rapid depolarization · Ca2+: triggers cardiac contraction · K+ Current: repolarization
31
Nitroglycerin (Cardiac Medication)
· Powerful vasodialator that decreases afterload thus decreasing the work of the heart
32
How do pacemakers decrease heart rate? (3 ways)
1) Decrease rate of depolarization 2) Shift maximum daistolic potential to start out more negative 3) Increase threshold (thus more time required to reach a positive threshold)
33
Inotropic Agents (Cardiac Medications)
· Modify contractility independent of pre/afterload and by raising/lowering Ca+ levels · Positive Inotropic Agent: ↑ contractility and work of the heart by ↑ Ca+ · Negative Inotropic Agent: ↓ contractility and work of the heart by ↓ Ca+
34
Where does gas exchange occur?
· Blood-air barrier (due to vessels lining the alveoli) · Type 1 Cells · Lung parenchyma
35
Visceral vs Parietal Pleura and Plueral Space
· Visceral Pleura: covers surface of lung and is inseperable from lung tissue · Parietal Pleura: covers inner surface of chest wall and exposed part of diapragm · Pleural Space: thin serous film that separates the 2 pleura and has an airtight seal to enhance lung expansion
36
Bohr's Method
· Expired CO2 comes from alveolar gas not dead space · Ex: Increase dead space means decreased expired CO2
37
How to decrease pulmonary vascular resistance (PVR)
· 2 Methods 1) Recruitment- opening of previously closed vessels 2) Distention- increase in the caliber of vessels that were already open
38
Alveolar Hypoxia
· Constriction of small pulmonary arteries as a way to direct blood flow away from poorly ventilated areas of the lungs
39
Hypoxemia
Drop in partial pressure of O2 in arterial blood
40
What can change ventilation or perfusion?
1) Intrapulmonary Shunt- no ventilation occurs 2) Alveolar Dead Space- no perfusion occurs
41
Respiratory Alkalosis
· Result of Hyperventilation causing a decrease in CO2 and thus an increase in pH
42
Compliance
· Ability to generate a certain volume at a certain pressure
43
Hysteresis
· Amount of pressure generated for a given volume · At a given pressure, volume during expiration > inspiration
44
What does surfactant affect?
· Reduces Surface tension to equalize pressure · Produced by Type 2 Pneumocytes · Decreased surfactannt can lead to difficulty inflating the lungs and potential of atelectasis (alveolar collapse)
45
Regulated variables in breathing?
Arterial blood gases (O2 and CO2) and pH
46
What has a greater influence of changing breathing- CO2 or O2?
CO2> O2
47
Obstructive vs Restrictive Patterns
1) Obstructive: decrease in expiratory airflow - decreased elastic recoil results in air trapping in lungs 2) Restrictive: decrease in lung volume
48
COPD Characteristics and 2 Main Types
Characteristics · ↓ elasticity · ↑ airway resistance · Air trapping 2 Main Types: 1) Chronic Bronchitis 2) Emphysema
49
Atherosclerosis
· Progressive hardening and narrowing of the arteries, occurs within the arterial walls * Cause of most heart and vascular diesases
50
Orthostatic Hypotension Diagnostic Requirements
· Drop in SBP >20 mm Hg · Drop in DBP >10 mm Hg · Increase in HR > 15bpm
51
Composition of Whole Blood
· Plasma (liquid) (47-64%) · Red Blood Cells (formed elements) · WBCs and platelets (buffy coat)
52
Hemoglobin vs Hemotocrit
· Hemoglobin: O2 carrying protein · Hemotocrit: % of whole blood that is composed of RBCs
53
Thrombocytopenia vs Thrombocytosis
· Thrombocytopenia: decrease in platelet count below 70,000 - increased risk for bruising · Thrombocytosis: increase in platelet count - due to hemostasis problem
54
Erythrocyte Function
1) Carry O2 to tissues 2) Carry CO2 to lungs 3) Buffer to maintain pH balance * Key factor is Hb
55
Oxygen Saturation
· Amount of Hb actually bound to O2 · Females: ~ 14.0 g/dL · Males: ~ 15.5g/dL
56
Screening for a DVT (Wells Clinical Decision Rules:DVT)
· Scored based on clinical liklihood of a DVT · Score of 0 or less = DVT unlikely · Score of 3+ = DVT highly likely
57
Normal Hb Ranges, Hematocrit, pH, PaCO2, PaO2
· Male: 14-18 g/dL · Female: 12-16 g/dL Hematocrit: · Males: 42-52% · Females: 37-47% pH: · 7.35-7.45 PaCO2: · 35-45 mm Hg PaO2: · 80-100 mg Hg