Week 11: Cardiorespiratory Care - Clinical Anatomy Flashcards
(152 cards)
1
Q
What level of vertebra is said to be heart shaped?
A
thoracic vertebra.
2
Q
The vertebral foramen is surrounded by how many pedicles and laminae?
A
The vertebral foramen is surrounded by two pedicles and two laminae
3
Q
At what vertebral level do the spinous process projects posteriorly (they are long and slope downwards)?
A
thoracic vertebra.
4
Q
On thoracic vertebrae, the superior articular facets are flat and face directly posteriorly, while the inferior articular facets face anteriorly.
What movement(s) does this vertical orientation limit? What movement(s) does it help facilitate
A
Limits flexion and extension of the vertebral column, but facilitates rotation.
5
Q
On thoracic vertebrae, how many demifacets does a typical vertebral body have? What articulates at these demifacets?
A
4 total: 2 demifacets on each side of the vertebral body (a superior and inferior costal facet) for the ribs to articulate.
6
Q
thoracic vertebrae - Look at the transverse process of the vertebra and the articular facet there – what specific portion of the rib articulates at this area?
A
Tubercle of the rib.
7
Q
What three anatomical structures can be found in the costal grooves?
A
Intercostal vein, artery and nerve.
8
Q
Which rib articulates at the manubriosternal joint?
A
2nd rib
9
Q
Fill in the blanks with the words inferior or superior.
Rib 5 articulates with the ____ costal facet of Vertebra 5 and the ______ costal facet of Vertebra 4.
A
superior
inferior
10
Q
What forms the boundaries of the superior thoracic aperture?
A
T1 vertebral body, Rib 1, and the superior manubrium
11
Q
What forms the boundaries of the inferior thoracic aperture?
A
T12 vertebral body, Rib 12, distal end of rib 11, cartilaginous ends of ribs 7-10, and xiphoid process. It is closed by the muscular diaphragm.
12
Q
When you take a breath in, the dimensions of the thorax change. As the diaphragm contracts, it descends, and this increases the vertical dimension of the thoracic cavity. What causes the anteroposterior and lateral dimensions of the thorax to change during inspiration?
A
rib elevation
When you take a breath in, the dimensions of the thorax change. As the diaphragm contracts, it descends, and this increases the vertical dimension of the thoracic cavity. The increase in anteroposterior and lateral dimensions of the thorax are the result of rib elevation.
13
Q
When you take a breath in, what causes the vertical dimension of the thoracic cavity to increase?
A
diaphragm
When you take a breath in, the dimensions of the thorax change. As the diaphragm contracts, it descends, and this increases the vertical dimension of the thoracic cavity. The increase in anteroposterior and lateral dimensions of the thorax are the result of rib elevation.
14
Q
The diaphragm is the primary muscle of inspiration. Why might isometric contraction of the intercostal muscles be important as intrathoracic pressure falls?
A
Isometric contraction is when you have muscular tension without contraction, so this helps to keep the thorax open, even when pressure falls, so that you create a zone of negative pressure which allows air to flow into the thorax during inspiration with little effort
15
Q
Why is the sterno-costal joint an important bony landmark?
A
A clinically useful feature of the manubriosternal joint is that it can be palpated easily. This is because the manubrium normally angles posteriorly on the body of sternum, forming a raised feature referred to as the sternal angle. This elevation marks the site of articulation of rib II with the sternum. Rib 1 is not palpable because it lies inferior to the clavicle and is embedded in
tissues at the base of the neck. Therefore, rib 2 is used as a reference for counting ribs and can be felt immediately lateral to the sternal angle. You can then use this rib reference to count ribs inferiorly to correctly place chest
drains or perform a thoracostomy/thoracotomy.
16
Q
True or false?
the pleural cavity projects above the first costal cartilage
A
True.
17
Q
the subclavian veins pass over the first rib, separated from the subclavian artery by what structure?
A
Scalenus anterior
18
Q
Why is this close relationship between the veins, arteries and the lung important when placing a cannula into the subclavian vein by the sub-clavicular route?
A
You do not want to perforate/puncture the subclavian artery that resides immediately deep to this vein. You also want to avoid puncturing the apex of the lung so that you don’t cause a pneumothorax or a mediastinal hematoma.
19
Q
A 60-year-old man attended A/E with pain in the left arm. An x-ray of his shoulder was requested, it showed Mass left apex likely to be carcinoma – Pancoast tumour.
Why might he have pain in his arm?
A
Infiltration of the brachial plexus.
20
Q
A 60-year-old man attended A&E with pain in the left arm. An x-ray of his shoulder was requested, it showed Mass left apex likely to be carcinoma – Pancoast tumour.
What should you examine his face for?
A
Ptosis left eye
Small pupil
21
Q
A 60-year-old man attended A/E with pain in the left arm. An x-ray of his shoulder was requested, it showed Mass left apex likely to be carcinoma – Pancoast tumour. You notice his left eye has ptosis and a small pupil.
What has happened to cause these signs?
A
Horner’s syndrome is characterized by a triad of symptoms - miosis (constriction of the pupil), partial ptosis (drooping of the superior eyelid), and anhydrosis (absence of sweating).
The mnemonic MAP is helpful in remembering the symptoms (M, miosis; A, anhydrosis; P, ptosis). The cause of these symptoms is disruption of the sympathetic
outflow to the dilator pupillae, smooth muscle of the levator palpebrae, and sweat glands.
This disruption is caused when the tumour involves the superior part of the sympathetic trunk and the first thoracic and inferior cervical ganglion. The inferior cervical ganglion is at level of the transverse process of vertebra CVII and is frequently fused with the first thoracic ganglion to form the cervicothoracic (stellate) ganglion.
22
Q
On chest x ray, you see that the horizontal fissure is raised. This is an indication of what?
A
Horizontal fissure raised. Collapse of right upper lobe – volume loss elevating the horizontal fissure.
23
Q
On CXR, you see opacity in right mid zone. What imaging would you ask for next if you saw this on an X-ray?
A
CT Thorax, likely to be neoplastic
24
Q
What is consolidation?
A
Consolidation is a radiological sign that refers to non-specific air-space opacification on a chest radiograph or chest CT. Many things can fill the alveolar spaces, including fluid (heart failure), pus (pneumonia), blood
(pulmonary haemorrhage) and cells (lung cancer).
25
A 48-year-old woman presents to the GP with increasing shortness of breath. CXR shows opacification in left lower zone and a meniscus fluid level.
What is the diagnosis?
pleural effusion.
26
What are the common causes of pleural effusion? (Divide the causes into: exudates and transudates)?
Transudates occur when there is an increase of hydrostatic pressure or a decrease of capillary oncotic pressure
· cardiac failure
· nephrotic syndrome
· cirrhosis
```
Exudates occur due to the increase in permeability in
microcirculation or alteration in the pleural space drainage to lymph nodes.
· bronchial carcinoma
· secondary (metastatic) malignancy
· pulmonary embolism and infarction
· pneumonia
· tuberculosis
· mesothelioma
· rheumatoid arthritis
· SLE
· lymphoma
```
27
A 70-year-old man presents with malaise, loss of appetite and weight loss. The GP arranges a chest X-ray that shows multiple opacities. What is the most likely diagnosis?
most likely multiple pulmonary metastases.
28
CXR hows sternal wires and a raid right hemi-diaphragm. Can you explain a posible link between the two findings?
Thoracic surgery (sternal wires) and raised right hemidiaphragm – injury to right phrenic nerve.
29
The interior of the right atrium is divided into a smooth part (derived from the right horn of the sinus venosus} and a part covered in ridges - pectinate muscles. What structure divides these types of muscle?
the smooth muscular ridge (crista terminalis) marks this division.
30
What chamber forms the most anterior surface of the heart?
the right ventricle forms most of the anterior surface of the heart. The right ventricle lies anteriorly to the right atrium.
31
Function of papillary muscles in the heart
There are three papillary muscles (anterior, posterior and septal). Contraction of the papillary muscles prevent cusp eversion into the right atrium during ventricular contraction.
32
the walls of the inflow portion of the right ventricle have
| muscular structures called...
trabeculae carneae
LV trabeculae carneae are similar to those in the
right ventricle.
33
The free edges of the tricuspid valve are attached to..
the chordae tendineae which arise from the tips of the papillary muscles.
34
True or false: The pulmonary valve has two semilunar cusps.
False. The pulmonary valve has three semilunar cusps.
35
What chamber of the heart forms the posterior surface?
the left atrium forms most of the posterior surface of the heart
36
Which three surfaces of the heart are formed by the left atrium?
The left ventricle forms the anterior, diaphragmatic and left pulmonary surfaces of the heart. It also forms the apex.
Note the left ventricle is somewhat posterior to the right ventricle.
37
How many cusps are there on the aortic valve?
consists of three semilunar cusps.
38
Describe the origin and course of the right coronary artery
RCA arises from the right aortic sinus of the ascending aorta. It descends in the sulcus between the right atrium and right ventricle.
39
List 4 structures supplied by the right coronary artery.
The right coronary artery supplies: right atrium, right
ventricle, SA node / AV node, Interatrial septum, part of left atrium, posterior inferior 1/3 of interventricular septum, posterior part of the left ventricle).
40
Describe the origin and course of the left coronary artery
LCA comes from left coronary sinus and passes between the pulmonary trunk and left auricle.
41
two terminal branches of left coronary artery
1. Anterior interventricular (LAD – left anterior
descending)
2. Circumflex branch (in the coronary sulcus)
42
What coronary artery branch is found in the coronary sulcus?
Circumflex branch
43
List 3 structures supplied by the left coronary artery.
The left coronary supplies left atrium, left ventricle,
| interventricular septum including AV bundle and branches.
44
ECG changes: Marked ST elevation in II, III and aVF with early Q-wave formation.
Reciprocal changes in aVL.
ST elevation in Lead III > II with reciprocal change present in lead I and ST
elevation in V1-2.
Which part of the heart is affected?
Which artery is most likely to be occluded?
Inferior
| The vast majority are the result of the occlusion of the right coronary artery
80%) (Circumflex 20%
45
ECG changes: Marked ST elevation in II, III and aVF with early Q-wave formation. Reciprocal changes in aVL.
ST elevation in Lead III > II with reciprocal change present in lead I and ST elevation in V1-2.
You decide the inferior part of the heart is affected.
The patient receives intravenous nitrates and becomes severely hypotensive. i) Why might this have happened? Ii) What repeat ECG would you perform?
Right ventricular infarction.
ECG with right sided leads.
ST elevation in VR3-6.
46
Patient has inferior STEMI. The patient receives intravenous nitrates and becomes severely
hypotensive. The ECG monitor now shows Inferior STEMI with third degree heart block and slow junctional escape rhythm.
What has happened and why?
Up to 20% of patients with inferior STEMI will develop either second- or third degree heart block.
There are two presumed mechanisms for this:
Ischaemia of the AV node due to impaired blood flow via the AV nodal artery. This artery arises from the RCA 80% of the time, hence its involvement in inferior STEMI due to RCA occlusion.
Bezold-Jarisch reflex = increased vagal tone secondary to ischaemia. The conduction block may develop either as a step-wise progression from 1st degree heart block via Wenckebach to complete heart block (in 50% of cases) or as abrupt onset of second or third-degree heart block (in the remaining 50%).
47
Patient has inferior STEMI and undergoes an angiogram performed via the right wrist.
1. What test do you perform to ensure the blood supply is intact to the hand prior to this procedure?
2. What two arteries is it testing?
Allen’s test.
Ulnar artery and Radial artery.
48
When performing a coronary arteriogram from the right wrist which arteries does the guidewire traverse from beginning to “end”?
Radial, brachial, axillary, subclavian, brachiocephalic, ascending aorta
49
The heart is found in the middle mediastinum, name 2 structures that are found in the posterior mediastinum.
Posterior: oesophagus, thoracic aorta, thoracic duct, azygous veins, splanchnic nerves, sympathetic nerves.
50
The heart is found in the middle mediastinum, name 2 structures that are found in the anterior mediastinum.
Anterior: Internal mammary arteries (internal thoracic artery), lymphatics, fat, thymus gland.
51
A 75-year-old man was admitted following a myocardial infarction. Five days later he became severely short of breath. On examination, he had a loud pan
systolic murmur loudest at the apex and radiating to the axilla. His respiratory rate was 28.min-1. He was using accessory muscles of respiration. He had bilateral crepitations extending midway up the lung fields.
What is likely to be the valve defect causing the murmur, and what two ventricles is this valve found between?
Mitral regurgitation.
Valve between the Left atrium and ventricle
52
List FOUR different accessory muscles of respiration?
Sternomastoid, scalenus anterior, pectoralis major, pectoralis minor, inferior fibres of serratus anterior and latissimus dorsi.
53
What is the "Bat Wings" sign on CXR?
Bilateral peri-hilar shadowing likely to be pulmonary oedema. “Bat wings”
Usually the result of cardiogenic sudden onset pulmonary oedema.
54
What are the irregular muscular columns which project from the inner surface of the right and left ventricles of the heart called?
irregular muscular columns which project from the inner surface of the right and left ventricles of the heart.
55
Explain how a ruptured papillary muscle, an arteriogram showing 90% obstruction of LAD and a CXR showing "bats wings" are all connected.
Occlusion of coronary artery – leads to myocardial infarction – this then leads to ischaemia of the papillary muscle – a rupture of the papillary muscle – then this causes the valve to fail, thus mitral regurgitation – then an acute left ventricular failure – which led to severe pulmonary oedema.
56
A 55-year-old man presents to the Emergency Department with severe “ripping” chest pain radiating to his back. He is pale and sweaty. On examination he has a tachycardia, unequal blood pressures in his upper limbs and a diastolic murmur over the left sternal edge.
What are you suspecting or concerned about?
You think he has an aortic dissection and arrange a CT scan.
57
A 55-year-old man presents to the Emergency Department with severe “ripping” chest pain radiating to his back. He is pale and sweaty. On examination he has a tachycardia, unequal blood pressures in his upper limbs and a diastolic murmur over the left sternal edge. You think he has an aortic
dissection and arrange a CT scan.
Looking at the CT scan, is the ascending aorta anterior or posterior to the descending aorta?
ascending aorta is anterior to the descending aorta.
58
Describe the layers of the wall of the aorta?
The aorta is composed of the tunica intima, media, and adventitia. The intima, the innermost layer, is thin, delicate, lined by endothelium, and easily
traumatized. The outermost layer of the aorta is adventitia. This largely consists of collagen. The vasa vasorum, which supplies blood to the outer half of the aortic wall, lies within the adventitia.
59
How does the structure of the aorta differ from peripheral arteries?
The tunica media is responsible for imparting strength to the aorta and consists of laminated but intertwining sheets of elastic tissue. The arrangement of these sheets in a spiral provides the aorta with its maximum
allowable tensile strength. The aorta’s tunica media contains very little smooth muscle and collagen between the elastic layers and thus has increased distensibility, elasticity, and tensile strength. This contrasts with
peripheral arteries, which, in comparison, have more smooth muscle and collagen between the elastic layers.
60
What is a dissection of the aorta and how does it occur?
Aortic dissection is defined as separation of the layers within the aortic wall. Tears in the intimal layer result in the propagation of the dissection (proximally or distally) with secondary to blood entering the intima-media space
61
How is aortic dissection classified according to the: DeBakey Classification and the Stanford Classification?
The DeBakey Classification:
· type 1 originates in ascending aorta, propagates at least to the aortic arch and often beyond it distally
· type 2 originates in and is confined to the ascending aorta
· type 3 originates in descending aorta, rarely extends proximally but will extend distally
The Stanford Classification:
· type A is any dissection that involves the ascending aorta (proximal)
· type B is any dissection does not involve the ascending aorta (distal)
62
What purposes might classification of aortic dissections have?
Guide treatment
Guide prognosis
Aid research/audit compare - “apples with apples”
63
What are the branches coming off of the Ascending aorta?
Right and left coronary arteries.
64
What are the branches coming off of the arch of the aorta?
Brachiocephalic, left common carotid, left subclavian arteries.
65
What are the branches coming off of the descending aorta in the thorax?
Intercostal branches
66
Name 1 structure that travels through the diaphragm alongside the aorta?
Thoracic duct, azygous vein.
67
A 55-year-old man presents to the Emergency Department with severe “ripping” chest pain radiating to his back. He is pale and sweaty. On examination he has a tachycardia, unequal blood pressures in his upper limbs and a diastolic murmur over the left sternal edge. You think he has an aortic dissection and arrange a CT scan.
Why can you hear a diastolic murmur in this patient? (two words)
Aortic regurgitation
68
A 55-year-old man presents to the Emergency Department with severe “ripping” chest pain radiating to his back. He is pale and sweaty. On examination he has a tachycardia, unequal blood pressures in his upper limbs and a diastolic murmur over the left sternal edge. You think he has an aortic dissection and arrange a CT scan.
Whilst waiting for transfer to the cardio-thoracic surgeons he becomes drowsy. He is hypotensive, heart sounds are muffled and you notice distended neck veins. What has happened? Explain your reasoning.
Dissection proximally leading to bleeding into the pericardial space. Resulting in reduced ventricular filling (due to pressure being put on the heart from the outside) and subsequent hemodynamic compromise by
reducing venous return and cardiac output. The pericardium, which is the membrane surrounding the heart, is composed of 2 layers. The thicker parietal pericardium is the outer fibrous layer; the thinner visceral
pericardium is the inner serous layer. The pericardial space normally contains 20-50mL of fluid.
69
What structures make up the right border extending upwards from the heart on CXR?
trachea
SVC
right atrium
70
At which rib level is the cardiac notch?
around rib 5
71
Between which ribs are the costo-diaphragmatic recesses in the anterior view?
Posterior view?
Anteriorly, lungs covered in visceral pleura stop around rib 8, parietal pleura extends to 10
Posteriorly, lungs covered in visceral pleura stop around rib 10, parietal pleura extends to beginnings of rib 12
72
A 27-year-old man presents to the Emergency Department with a sudden onset of sharp left sided chest pain. He is mildly short of breath at rest. On examination, his respiratory rate is 28/min, pulse 100 and blood pressure 130/70. There are reduced breath sounds on the left and the left side is more resonant than the right. He has had a chest x-ray. What might you expect to see on chest X-ray?
Left side – no lung markings (likely a collapsed lung).
| Large pneumothorax.
73
A 27-year-old man presents to the Emergency Department with a sudden onset of sharp left sided chest pain. He is mildly short of breath at rest. On examination, his respiratory rate is 28/min, pulse 100 and blood pressure 130/70. There are reduced breath sounds on the left and the left side is more resonant than the right. He has had a chest x-ray, which shows no lung markings on the left side.
Following a procedure, a repeat x ray is normal. What procedure has been performed?
Left sided chest drain with inflation of the lung.
74
Anatomically, where should a chest drain be inserted?
Normally inserted in 5th intercostal space along the anterior axillary line
Safe triangle - This is the triangle bordered by the anterior border of the latissimus dorsi, the lateral border of the pectoralis major muscle.
SA - a line superior to the horizontal level of the nipple, and an apex below the axilla.
75
List five possible complications of chest drain insertion?
· Haemothorax, usually from laceration of intercostal vessel
· Lung laceration
· Diaphragm / Abdominal cavity penetration (placed too low – the
diaphragm lies surprisingly high)
· Stomach / colon injury (diaphragmatic hernia not recognised)
· Tube placed subcutaneously (not in thoracic cavity)
· Tube placed too far
· Tube falls out (not secured properly)
76
Does a normal liver extend above the xiphisternum?
Yes, normal liver is found behind this landmark
77
You are working in the Emergency Department and a 70-year-old man with known bullous COPD who presents with sudden shortness of breath. On examination, you find they have no air entry on the left side of their chest,
and it is hyper resonant to percussion, their trachea is shifted to the right.
What is the diagnosis?
Tension pneumothorax.
78
You are working in the Emergency Department and a 70-year-old man with known bullous COPD who presents with sudden shortness of breath. On examination, you find they have no air entry on the left side of their chest,
and it is hyper resonant to percussion, their trachea is shifted to the right. You diagnose tension pneumothorax.
Explain, in terms of the anatomy of the lung, what has happened and why this has resulted in these clinical signs.
It is likely that a bulla has burst resulting in a pneumothorax where air has leaked between the visceral and parietal pleura of the lung compressing the lung. This is why there are no air sounds when you listen over the lung and the air is hyper-resonant when you percuss over it. A one-way valve has been created that lets air out but does not let air back into the parenchyma of the lung. Therefore, as time goes on more and more air is building up in the parietal space and starting to compress midline structures in the mediastinum. This is why the trachea has shifted away from the side of the pneumothorax
79
What are the anatomical borders of the superior mediastinum?
Superior: The thoracic inlet, the upper opening of the thorax.
Inferior: The transverse thoracic plane.
Laterally: The pleurae.
Anterior: The manubrium of the sternum.
Posterior: The first four thoracic vertebral bodies.
80
Name 3 visceral organs found in the superior mediastinum
oesophagus, trachea, thymus
81
Name 3 nerves that run through the superior mediastinum
phrenic nerve, vagus nerve, left recurrent laryngeal nerve
82
Name 2 nerve plexuses that run through the superior mediastinum
cardiac plexus branches, pulmonary plexus branches
Note: phrenic nerve, vagus nerve, left recurrent laryngeal nerve run through the superior mediastinum as well.
83
Name the major veins in the superior mediastinum
svc, brachiocephalic veins
84
Name the major arteries in the superior mediastinum
Aortic arch, brachiocephalic artery, common carotid artery, left subclavian artery
85
Name the major lymphatic structure in the superior mediastinum
Thoracic duct
86
You are working in the Emergency Department and a 70-year-old man with known bullous COPD who presents with sudden shortness of breath. On examination, you find they have no air entry on the left side of their chest,
and it is hyper resonant to percussion, their trachea is shifted to the right. You diagnose tension pneumothorax.
Due to this mediastinal shift, you must perform an emergency procedure to release the air. What is this procedure called?
Needle thoracostomy
87
How are Needle thoracostomy performed to treat tension pneumothorax?
Place a 14-16G IV cannula into the second rib space in the midclavicular line. Be sure to insert it on the top of the third rib, not at the bottom of the second rib, to avoid damaging the neurovascular bundle. Advance the needle until you can aspirate air into a syringe that is connected to the needle, withdraw the needle and leave the cannula open to air and air should rush out converting the tension pneumothorax into a simple pneumothorax.
88
You place a chest drain on the left side of the chest in the 5th intercostal space. What layers will the chest drain pass through and in what order?
Skin, fat, external intercostal muscle, internal intercostal muscle, innermost intercostal muscle, endothoracic fascia, and parietal pleura.
89
After placing a chest drain it fills with blood that is coming out in a pulsatile manner- where do you think you have placed it?
What should you do next?
In the left ventricle.
Don’t panic. Clamp the drain to prevent loss of blood and call cardiothoracic surgeons.
90
A ten-week-old infant attends the GP with failure to thrive and blue episodes whilst crying and feeding. Tetralogy of Fallot is suspected and the child is referred to the paediatric cardiologists.
What FOUR cardiac abnormalities make up the Tetralogy of Fallot?
Pulmonary stenosis
Septal defect
Overriding aorta
RV hypertrophy
91
A ten-week-old infant attends the GP with failure to thrive and blue episodes whilst crying and feeding. Tetralogy of Fallot is suspected and the child is referred to the paediatric cardiologists.
Why is the infant blue?
Right to left shunt – deoxygenated blood into systemic circulation.
During feeding or crying, Cyanosis “Tet Spells”
due to taxing the pulmonary
and vascular system
92
A ten-week-old infant attends the GP with failure to thrive and blue episodes whilst crying and feeding. Tetralogy of Fallot is suspected and the child is referred to the paediatric cardiologists.
What non-invasive test is used to help determine the anatomical abnormalities?
Echocardiogram.
93
What is the equivalent adult structure of the umbilical artery?
Medial umbilical ligament
note: umbilical vein becomes ligamentous teres
94
What is the equivalent adult structure of the umbilical vein ?
Ligamentum teres
Note: umbilical artery becomes medial umbilical ligament
95
What is the equivalent adult structure of the ductus venosus?
Ligamentum Venosum
96
What is the equivalent adult structure of the foramen ovale?
Fossa ovalis
97
What is the equivalent adult structure of the ductus arteriosum?
Ligamentum arteriosum
98
In foetal life what factors keep the ductus arteriosus patent?
1. low oxygen tension (nonfunctioning lungs)
2. High levels of circulating prostaglandins acting to keep the ductus open. The high levels of prostaglandins result from low metabolism of prostaglandins in the lung and the high levels of production in the placenta.
99
What factors promote duct closure of the ductus arteriosus at birth?
a. the placenta is removed, eliminating a major source of
prostaglandin production.
b. lungs expand activating prostaglandin metabolism.
c. onset of normal respiration increasing oxygen tension.
d. pulmonary vascular resistance decreases.
Functional closure of the ductus arteriosus occurs by about 15 hours of life in healthy infants born at term. This occurs by abrupt contraction of the muscular wall of the ductus arteriosus, which is associated with increases in
the pO2. Shift of blood flow from the ductus and directly from the right ventricle into the lungs. True anatomic closure, in which the ductus loses the ability to reopen, may take several weeks.
100
What is patent ductus arterioles and why is it important?
True anatomic closure, in which the ductus loses the ability to reopen, may take several weeks after birth. Patency after 3 months is considered abnormal, and
treatment should be considered. Left untreated, patients with a large patent ductus arteriosus are at risk of
developing Eisenmenger Syndrome, in which the pulmonary vascular resistance can exceed systemic vascular resistance and the usual left-to-right
shunting reverses to a right-to-left direction.
101
What nerve hooks around the ductus arteriosus?
Left recurrent laryngeal nerve.
102
A term baby develops cyanosis a couple of hours after delivery. It is thought he has transposition of the great vessels.
Anatomically, what has happened in this condition?
The aorta arises from the right ventricle and pulmonary artery arises from the left ventricle.
103
A term baby develops cyanosis a couple of hours after delivery. It is thought he has transposition of the great vessels.
1. How is the baby able to survive until the abnormality is surgically corrected?
2. What drug might be useful while waiting for surgical correction?
The aorta arises from the RV and pulmonary artery arises from the LV.
Transposition results in two circuits in parallel, not in series, unless blood is able to mix between the circuits the baby will die from lack of oxygen.
Mixing can occur through a VSD, ASD or PDA
IV Prostaglandin- to keep the duct open.
104
Where is the Safe triangle for chest drain insertion?
Safe triangle - This is the triangle bordered by the anterior border of the latissimus dorsi, the lateral border of the pectoralis major muscle.
105
Define the Mediastinum
Region between the lungs, extending from the sternum to the bodies of the vertebrae & from the superior thoracic
aperture (thoracic inlet) to the diaphragm
106
The sternal angle aligns with the junction of which two vertebrae?
T4 and T5
107
The posterior mediastinum extends inferiorly to which
| vertebrae?
12th thoracic
108
Where is the best place to auscultate the aortic valve?
2nd R ICS
109
Where is the best place to auscultate the pulmonary valve?
2nd L ICS
110
Where is the best place to auscultate the mitral valve?
5th L ICS MCL
111
Where is the best place to auscultate the tricuspid valve?
4/5th L ICS
112
What is a normal heart size?
less than 50% width of cXR
about the size of patients fist
113
innervation of oesophagus
Sensory & motor nerve supply from Vagus n.
114
Which mediastinal compartments is the oesophagus found in?
Sits in superior & posterior mediastinum
115
To what is the Fibrous pericardium bound inferiorly?
Fibrous pericardium
| - Binds to the central diaphragmatic tendon
116
Cardiac autonomic plexus located between which two structures?
aorta & trachea
117
What anatomical relationship allows for transoesophageal cardiac ultrasound?
part of the oesophagus sits behind
| the left atrium in the posterior mediastinum
118
Vagal fibres form a plexus around the oesophagus. Are these anterior or posterior? Explain.
Vagal trunks travel through diaphragm on the anterior (left vagus) & posterior (right vagus) surfaces of oesophagus
119
Describe the different positions of
the recurrent laryngeal nerves
on L & R sides
```
R= loops under right subclavian artery
L= loops under aortic arch
```
120
Describe the course of vagal nerves through the thorax
Vagus nerves (CN X) run anterior to subclavian vessels and descend through mediastinum
CN X travels posterior to the
lung root on both sides
Vagal trunks travel through diaphragm on the anterior (left vagus) & posterior (right vagus) surfaces of oesophagus
121
How do vagal and phrenic nerves differ in their relationship to lungs?
CN X travels posterior to the
lung root on both sides
Phrenic nerve in front of root of lung towards diaphragm
122
Sympathetic Supply to the Heart
Increases Heart Rate & Contractility
Arise from T1-T4 derived-parts of the sympathetic chain (give off splanchnic nerves)
Cardiac nerves descend through the neck to heart
Cardiac visceral sensory fibres travel back to the CNS with sympathetic
nerves –referred cardiac pain occurs in the medial upper limb &
superolateral thoracic wall
123
What is the Pericardium?
fibroserous sac surrounding the heart and the roots of the great vessels
2 components: Fibrous Pericardium & Serous Pericardium
Serous pericardium consists of TWO parts: Parietal and visceral
124
What is the nerve supply to the pericardium?
Phrenic nerve
125
Serous pericardium consists of which TWO parts:
1. Parietal layer (lines inner surface of the Fibrous pericardium)
2. Visceral Layer (EPICARDIUM) Adheres to heart and forms outer covering
Two layers are continuous at the roots of the great vessels
Small space between the 2 layers = Pericardial Cavity
Cavity contains small amount of fluid
126
Common categories of causes of pericardial effusion
Excess fluid in the Pericardial cavity
Result of: Inflammatory disease, trauma
127
Treatment for cardiac tamponade?
pericardiocentesis
128
Causes of pericarditis
Bacterial, viral or fungal infections
Post-myocardial infarction
Malignancy
Systemic illnesses (autoimmune, chronic renal failure)
129
Symptoms of pericarditis
Pain (received by sitting up and leaning forward)
| Pericardial Friction Rub
130
Nerve supply to pericardium,
phrenic nerve
131
What is Pericardial Friction Rub?
Very specific for pericarditis
Normally: layers of the serous pericardium make no detectable sound during auscultation
In Pericarditis: surfaces become rough make a rustling silk, scratchy, squeaky sound
132
How does normal jugular pulse change during inspiration?
Normal jugular pulse decreases when you inspire, due to increased volume of thorax. Rush of venous return.
Kussmauls' sign - Kussmaul’s sign - JVP goes up during inspiration. No venous return due to constriction of heart by fibrous pericardium in pericarditis.
133
What is Kussmauls' sign?
Normal jugular pulse decreases when you inspire, due to increased volume of thorax. Rush of venous return.
Kussmauls' sign - Kussmaul’s sign - JVP goes up during inspiration. No venous return due to constriction of heart by fibrous pericardium in pericarditis.
134
During development the heart is a midline structure that rotates to the left. As a result, Right sided structures
sit _____
anteriorly
135
During development the heart is a midline structure that rotates to the left. As a result, left sided structures
sit _____
posteriorly
136
What is the Transverse pericardial sinus?
passageway between the arterial output and the venous input
Can be used in surgery to clamp arterial outflow
137
What innervates the parietal pleura?
Highly innervated by intercostal nerves can feel pain
138
What are the three most likely locations of coronary artery occlusion?
left anterior descending (LAD)
right coronary artery proximal
circumflex artery branch of left coronary
139
Clinically significant ASDs Cause:
– Oxygenated blood to be shunted from LA through defect into RA
– Enlargement of right atrium and ventricle
– Dilation of pulmonary trunk (outflow tract)
140
Clinically significant VSDs Cause:
Increased volume load to RV
thus increased pressures in the pulmonary arteries and lungs LV hypertrophy
Increased pulmonary blood flow/venous pressure
Hypertension, Pulmonary Disease and possible cardiac failure.
141
What two valves are out commonly affected in valvular heart disease?
Mitral and Aortic valve most commonly affected
142
Mitral Valve Prolapse
Insufficient or incompetent valve one or both leaflets are enlarged or FLOPPY. Results in leaflets extending back into the LA during systole
Blood regurgitates into LA, when LV contracts Late systolic murmur
Most common type of congenital heart disease in adults
143
Clinical consequences of Mitral Valve Prolapse
```
LV hypertrophy
LA dilation
Increased pulmonary pressure
Pulmonary edema
Shortness of breath
Right sided heart failure
```
144
Why do patients feel pain during an MI?
Heart is insensitive to touch/cold/pain/heat
However, ischemia triggers visceral pain endings in the myocardium
Visceral afferent pain fibers run through sympathetic trunk into spinal cord from
T1-T5* especially on the LEFT side!
145
Why does cardiac pain refer to the upper limb?
Cardiac pain is referred to the upper limb because the visceral “pain” fibers of the heart that run through the
sympathetic trunk use ganglia and posterior roots to get into the spinal cord that are the same ganglia and posterior roots as the sensory nerves that are coming in from the arm. Thus the sensory nerve endings that are coming in from the arm are coming into the same ganglia and posterior roots of the spinal cord that the visceral pain fibers of the heart are…thus the signals get crossed and we can perceive a MI as a painful left arm!
146
True or false?
Aortic Dissection results from a tear in the aortic media
False - Results from a tear in the aortic intima
147
Aortic dissection Typically presents with:
Chest pain
Can be associated with syncope
Symptoms of stroke/MI
148
Risk factors for aortic dissection
Age
Male
Systemic hypertension
Preexisting aortic aneurysm
149
Coarctation of the Aorta
Congenital abnormality
Aortic lumen is constricted just distal to the origin of the
left subclavian artery
150
Consequences of coarctation of aorta
Diminished blood flow to the lower limbs and abdomen
Higher pressure needed to maintain peripheral perfusion
Cardiac failure due to increased stress
151
How might the ductus arteriosus be involved in coarctation of the aorta?
ductus arteriosus becomes ligamentum arteriosum
| this process irregular, causes pinching of aorta
152
Why is rib notching a sign of coarctation of the aorta?
To compensate collateral routes are used, collateral vessels develop. Any forces pulling on bone over time will reshape it, resulting in Rib notching
