Amy's lectures

Question 1

Thoracic Cage

Answer 1

• sternum (manubrium, body, xiphoid process)
• 12 pairs of ribs and their costal cartilages
• 12 thoracic vertebrae and their intervertebral discs
• collectively create the thoracic cavity

Question 2

Thoracic Wall

Answer 2

• aka chest wall
• thoracic cage plus all the associated skin, fascia, and muscles
• provides attachments for muscles of the neck, upper limbs, abdomen and back

Functions:

• protects the contents of the thoracic cavity (Heart, Great Vessels, Lungs, Liver, Trachea, Spleen)
• provide mechanical function of breathing

Question 3

Ribs

Answer 3

• True 1-7
• False 8-10
• Floating: 11 &12
• Typical 3-9
• Atypical 1-2, 10-12
• Hematopoetic

Question 4

Typical Ribs

Answer 4

Typical 3-9

• Head - 2 facets separated by crest of head
• Neck - connects head to body (aka shaft)
• Tubercle - junction of the neck and shaft
• shaft - thin, flat, curved (costal angle; costal groove)

Question 5

1st Rib

Answer 5

• Broadest, shortest, most angled
• single facet - T1
• Tubercle on superior surface
• 2 transverse grooves separated by scalene tubercle (for subclavian vessels)

Question 6

Ribs 2 and 10-12

Answer 6

Second RIb

• less curved and longer than the 1st
• 2 facets
• additional tubercle for muscle attachment

10-12

• only one facet

11-12 (floating)

• short
• no neck or tubercles

Question 7

Rib Injuries

Answer 7

• Fractures
• Flail Chest
• Thoracotomy

Question 8

Flail Chest

Answer 8

A flail chest is a life-threatening medical condition that occurs when a segment of the rib cage breaks under extreme stress and becomes detached from the rest of the chest wall. It occurs when multiple adjacent ribs are broken in multiple places, separating a segment, so a part of the chest wall moves independently. The number of ribs that must be broken varies by differing definitions: some sources say at least two adjacent ribs are broken in at least two places,[1] some require three or more ribs in two or more places.[2] The flail segment moves in the opposite direction as the rest of the chest wall: because of the ambient pressure in comparison to the pressure inside the lungs, it goes in while the rest of the chest is moving out, and vice versa. This so-called “paradoxical motion” can increase the work and pain involved in breathing. Studies have found that up to half of people with flail chest die. [3]

Flail chest is invariably accompanied by pulmonary contusion, a bruise of the lung tissue that can interfere with blood oxygenation.[4] Often, it is the contusion, not the flail segment, that is the main cause of respiratory failure in patients with both injuries.[5]

Question 9

Thoracotomy

Answer 9

A thoracotomy or thoracostomy is an incision into the pleural space of the chest.[1] It is performed by surgeons (or emergency physicians under certain circumstances) to gain access to the thoracic organs, most commonly the heart, the lungs, or the esophagus, or for access to the thoracic aorta or the anterior spine (the latter may be necessary to access tumors in the spine).

Thoracotomy is a major surgical maneuver—it is the first step in many thoracic surgeries including lobectomy or pneumonectomy for lung cancer—and as such requires general anesthesia with endotracheal tube insertion and mechanical ventilation.

Thoracotomies are thought to be one of the most difficult surgical incisions to deal with post-operatively, because they are extremely painful and the pain can prevent the patient from breathing effectively, leading to atelectasis or pneumonia.

Question 10

Supernumary Ribs

Answer 10

A cervical rib in humans is a supernumerary (or extra) rib which arises from the seventh cervical vertebra. Sometimes known as “neck ribs”,[1] their presence is a congenital abnormality located above the normal first rib. A cervical rib is present in only about 1 in 500 (0.2%) of people;[2] in even rarer cases, an individual may have two cervical ribs.

The presence of a cervical rib can cause a form of thoracic outlet syndrome due to compression of the lower trunk of the brachial plexus or subclavian artery. These structures are entrapped between the cervical rib and scalenus muscle.

Compression of the brachial plexus may be identified by weakness of the muscles around the muscles in the hand, near the base of the thumb. Compression of the subclavian artery is often diagnosed by finding a positive Adson’s sign on examination, where the radial pulse in the arm is lost during abduction and external rotation of the shoulder.

Extra lumbar ribs are the next most common, but don’t often result in any issues.

Question 11

Thoracic Outlet Syndrome

Answer 11

Thoracic outlet syndrome (TOS) is a syndrome involving compression at the superior thoracic outlet[1] wherein excess pressure placed on a neurovascular bundle passing between the anterior scalene and middle scalene muscles.[2] It can affect one or more of the nerves that innervate the upper limb and/or blood vessels as they pass between the chest and upper extremity; specifically in the brachial plexus, the subclavian artery, and - rarely - the subclavian vein, which does not normally pass through the scalene hiatus.

TOS may occur due to a positional cause - for example, by abnormal compression from the clavicle (collarbone) and shoulder girdle on arm movement. There are also several static forms, caused by abnormalities, enlargement, or spasm of the various muscles surrounding the arteries, veins, and/or brachial plexus, a fixation of a first rib, or a cervical rib. A Pancoast tumor (a rare form of lung cancer in the apex of the lung) can lead to thoracic outlet syndrome in the progressive stages of the disease. The most common causes of thoracic outlet syndrome include physical trauma from a car accident, repetitive strain injury from a job such as frequent non-ergonomic use of a keyboard, sports-related activities and anatomical defects such as having an extra rib. In pregnancy, if a narrow superior thoracic outlet exists previously, the patient can have symptoms for the first time. Joints loosen during pregnancy, making it easier to develop bad posture.[3]

Question 12

Dermatomes

Answer 12

Question 13

Shingles

Answer 13

Herpes zoster (or simply zoster), commonly known as shingles and also known as zona, is a viral disease characterized by a painful skin rash with blisters in a limited area on one side of the body (left or right), often in a stripe. The initial infection with varicella zoster virus (VZV) causes the acute, short-lived illness chickenpox which generally occurs in children and young adults. Once an episode of chickenpox has resolved, the virus is not eliminated from the body but can go on to cause shingles — an illness with very different symptoms — often many years after the initial infection. Herpes zoster is not the same disease as herpes simplex, despite the name similarity; both the varicella zoster virus and herpes simplex virus belong to the same viral subfamily Alphaherpesvirinae.

The earliest symptoms of herpes zoster, which include headache, fever, and malaise, are nonspecific, and may result in an incorrect diagnosis.[5][10] These symptoms are commonly followed by sensations of burning pain, itching, hyperesthesia (oversensitivity), or paresthesia (“pins and needles”: tingling, pricking, or numbness).[11] The pain may be mild to extreme in the affected dermatome, with sensations that are often described as stinging, tingling, aching, numbing or throbbing, and can be interspersed with quick stabs of agonizing pain.[12]

Herpes zoster in children is often painless, but older people are more likely to get zoster as they age, and the disease tends to be more severe.[13]

In most cases after one to two days, but sometimes as long as three weeks, the initial phase is followed by the appearance of the characteristic skin rash. The pain and rash most commonly occurs on the torso, but can appear on the face, eyes or other parts of the body. At first the rash appears similar to the first appearance of hives; however, unlike hives, herpes zoster causes skin changes limited to a dermatome, normally resulting in a stripe or belt-like pattern that is limited to one side of the body and does not cross the midline.[11] Zoster sine herpete (“zoster without herpes”) describes a patient who has all of the symptoms of herpes zoster except this characteristic rash.[14]

Later the rash becomes vesicular, forming small blisters filled with a serous exudate, as the fever and general malaise continue. The painful vesicles eventually become cloudy or darkened as they fill with blood, crust over within seven to ten days; usually the crusts fall off and the skin heals, but sometimes, after severe blistering, scarring and discolored skin remain

Question 14

Cardiac Tamponade

Answer 14

Cardiac tamponade, also known as pericardial tamponade, is an acute type of pericardial effusion in which fluid accumulates in the pericardium (the sac in which the heart is enclosed).

Cardiac tamponade is pressure on the heart muscle which occurs when the pericardial space fills up with fluid faster than the pericardial sac can stretch. If the amount of fluid increases slowly (such as in hypothyroidism) the pericardial sac can expand to contain a liter or more of fluid prior to tamponade occurring. If the fluid occurs rapidly (as may occur after trauma or myocardial rupture) as little as 100 ml can cause tamponade.[1]

Causes of increased pericardial effusion include hypothyroidism, physical trauma (either penetrating trauma involving the pericardium or blunt chest trauma), pericarditis (inflammation of the pericardium), iatrogenic trauma (during an invasive procedure), and myocardial rupture. One of the most common cause is after heart surgery, when post operative bleeding fails to be cleared by clogged chest tubes.

The outer layer of the heart is made of fibrous tissue[7] which does not easily stretch, and so once fluid begins to enter the pericardial space, pressure starts to increase.[2]

If fluid continues to accumulate, then with each successive diastolic period, less and less blood enters the ventricles, as the increasing pressure presses on the heart and forces the septum to bend into the left ventricle, leading to decreased stroke volume.[2] This causes obstructive shock to develop, and if left untreated then cardiac arrest may occur (in which case the presenting rhythm is likely to be pulseless electrical activity).

Question 15

Pneumothorax

Answer 15

A pneumothorax (pl. pneumothoraces) is an abnormal collection of air or gas in the pleural space that separates the lung from the chest wall and which may interfere with normal breathing.

A primary pneumothorax is one that occurs without an apparent cause and in the absence of significant lung disease, while a secondary pneumothorax occurs in the presence of existing lung pathology. In a minority of cases, the amount of air in the chest increases markedly when a one-way valve is formed by an area of damaged tissue, leading to a tension pneumothorax. This condition is a medical emergency that can cause steadily worsening oxygen shortage and low blood pressure. Unless reversed by effective treatment, these sequelae can progress and cause death.

Pneumothoraces can be caused by physical trauma to the chest (including blast injury), or as a complication of medical or surgical intervention. Symptoms typically include chest pain and shortness of breath. Diagnosis of a pneumothorax by physical examination alone can be difficult or inconclusive (particularly in smaller pneumothoraces), so a chest X-ray or computed tomography (CT) scan is usually used to confirm its presence.

Small spontaneous pneumothoraces typically resolve without treatment and require only monitoring. This approach may be most appropriate in subjects who have no significant underlying lung disease. In larger pneumothoraces, or when there are marked symptoms, the air may be extracted with a syringe or a chest tube connected to a one-way valve system. Occasionally, surgical interventions are required when tube drainage is unsuccessful, or as a preventive measure, if there have been repeated episodes. The surgical treatments usually involve pleurodesis (in which the layers of pleura are induced to stick together) or pleurectomy (the surgical removal of pleural membranes).

Question 16

Hydrothorax

Answer 16

Hydrothorax is a condition that results from serous fluid accumulating in the pleural cavity. This specific condition can be related to cirrhosis with ascites in which ascitic fluid leaks into the pleural cavity. Hepatic hydrothorax is often difficult to manage in end-stage liver failure and often fails to respond to therapy.

In similar pleural effusions, the fluid is blood in hemothorax (as in major chest injuries), pus in pyothorax (resulting from chest infections), and lymph in chylothorax (resulting from rupture of the thoracic duct).

Question 17

Hemothorax

Answer 17

Its cause is usually traumatic, from a blunt or penetrating injury to the thorax, resulting in a rupture of the serous membrane either lining the thorax or covering the lungs. This rupture allows blood to spill into the pleural space, equalizing the pressures between it and the lungs. Blood loss may be massive in people with these conditions, as each side of the thorax can hold 30–40% of a person’s blood volume. Even minor injury to the chest wall can lead to significant hemothorax.

Question 18

Atelectasis (primary vs. secondary)

Answer 18

Failure of the lung to expand fully at birth. In contrast to secondary atelectasis in which there is partial or complete collapse of a lung that once had expanded, as may happen after chest surgery.

Question 19

Foreign Body Aspiration

Answer 19

Foreign body aspiration can be a life-threatening emergency. An aspirated solid or semisolid object may lodge in the larynx or trachea. If the object is large enough to cause nearly complete obstruction of the airway, asphyxia may rapidly cause death. Lesser degrees of obstruction or passage of the obstructive object beyond the carina can result in less severe signs and symptoms.

Chronic debilitating symptoms with recurrent infections might occur with delayed extraction, or the patient may remain asymptomatic. The actual aspiration event can usually be identified, although it is often not immediately appreciated. The aspirated object might even escape detection. Most often, the aspirated object is food, but a broad spectrum of aspirated items has been documented over the years. Commonly retrieved objects include seeds, nuts, bone fragments, nails, small toys, coins, pins, medical instrument fragments, and dental appliances.

Question 20

Pleuritis

Answer 20

Pleurisy (also known as pleuritis) is an inflammation of the pleura, the lining surrounding the lungs.[1] There are many possible causes of pleurisy but viral infections spreading from the lungs to pleural cavity are the most common.[2] The inflamed pleural layers rub against each other every time the lungs expand to breathe in air.[3] This can cause sharp pain when breathing, also called pleuritic chest pain.[4][5]

Question 21

Pulmonary Embolism

Answer 21

Pulmonary embolism (PE) is a blockage of the main artery of the lung or one of its branches by a substance that has travelled from elsewhere in the body through the bloodstream (embolism). PE most commonly results from deep vein thrombosis (a blood clot in the deep veins of the legs or pelvis) that breaks off and migrates to the lung, a process termed venous thromboembolism (VTE). A small proportion of cases are due to the embolization of air, fat, or talc in drugs of intravenous drug abusers or amniotic fluid. The obstruction of the blood flow through the lungs and the resultant pressure on the right ventricle of the heart lead to the symptoms and signs of PE. The risk of PE is increased in various situations, such as cancer or prolonged bed rest.[1]

Symptoms of pulmonary embolism include difficulty breathing, chest pain on inspiration, and palpitations. Clinical signs include low blood oxygen saturation and cyanosis, rapid breathing, and a rapid heart rate. Severe cases of PE can lead to collapse, abnormally low blood pressure, and sudden death.[1]

Diagnosis is based on these clinical findings in combination with laboratory tests (such as the D-dimer test) and imaging studies, usually CT pulmonary angiography. Treatment is typically with anticoagulant medication, including heparin and warfarin. Severe cases may require thrombolysis with drugs such as tissue plasminogen activator (tPA) or may require surgical intervention via pulmonary thrombectomy.

Question 22

COPD

Answer 22

Chronic obstructive pulmonary disease (COPD), also known as chronic obstructive lung disease (COLD), chronic obstructive airway disease (COAD), chronic airflow limitation (CAL) and chronic obstructive respiratory disease (CORD), is the occurrence of chronic bronchitis or emphysema, a pair of commonly co-existing diseases of the lungs in which the airways narrow over time.[1] This limits airflow to and from the lungs, causing shortness of breath.

COPD is caused primarily by tobacco smoke, with an number of other factors playing a less common role.[2] This triggers an inflammatory response in the lung.[3] COPD is often defined based on low airflow on lung function tests.[4] In contrast to asthma, this limitation is poorly reversible and usually gets increasingly worse over time.

Management involves quiting smoking, vaccinations, rehabilitation, and often inhaled bronchodilators. Some people require long-term oxygen therapy or lung transplantation.[3]

Worldwide, COPD ranked as the sixth leading cause of death in 1990. Mortality is expected to increase due to an increase in smoking rates and an aging population in many countries.[5] COPD is the third leading cause of death in the U.S., and the economic burden of COPD in the U.S. in 2007 was $42.6 billion in health care costs and lost productivity.

tachypnea, a rapid breathing rate
 wheezing sounds or crackles in the lungs heard through a stethoscope
 breathing out taking a longer time than breathing in
 enlargement of the chest, particularly the front-to-back distance (hyperaeration)
 active use of muscles in the neck to help with breathing
 breathing through pursed lips
 increased anteroposterior to lateral ratio of the chest (i.e. barrel chest).

Question 23

Thoracentesis

Answer 23

Thoracentesis /ˌθɔrəsɨnˈtiːsɨs/, (from Greek, thorax + centesis, puncture) also known as thoracocentesis or pleural tap, is an invasive procedure to remove fluid or air from the pleural space for diagnostic or therapeutic purposes. A cannula, or hollow needle, is carefully introduced into the thorax, generally after administration of local anesthesia.

Question 24

Chest Tube

Answer 24

A chest tube (chest drain, thoracic catheter, tube thoracostomy, or intercostal drain) is a flexible plastic tube that is inserted through the chest wall and into the pleural space or mediastinum. It is used to remove air (pneumothorax[2]) or fluid (pleural effusion, blood, chyle), or pus (empyema) from the intrathoracic space. It is also known as a Bülau drain or an intercostal catheter.

Question 25

Thoracoscopy

Answer 25

Thoracoscopy is a medical procedure involving internal examination, biopsy, and/or resection of disease or masses within the pleural cavity and thoracic cavity.[1] Thoracoscopy may be performed either under general anaesthesia or under sedation with local anaesthetic. thoracoscopy is performed using specialized thoracoscopes. These instruments include a light source and a lens for viewing and may have ports through which other instruments may be inserted for the purpose of tissue removal and manipulation.

Question 26

Pleurectomy

Answer 26

Pleurectomy is a type of surgery in which part of the pleura is removed. This procedure helps to prevent fluid from collecting in the affected area and is used for the treatment of mesothelioma, a pleural mesothelial cancer.[1] Pleurectomy provides symptomatic relief but does not appear to benefit survival rates.

Malignant pleural effusions generally result from metastatic spread of disease to the pleura and are commonly seen in the course of many tumors. Less frequently, effusions are associated with primary tumors of lung, pleura, or mediastinum.

Many nonsurgical methods have been proposed to control effusion and to improve respiratory function. Nonetheless, many studies have demonstrated the benefits of pleurectomy in patients with malignant effusions secondary to various cancers.[2]

Pleurectomy reduces the risk of symptomatic pleural effusions and recurrence of spontaneous pneumothorax.[3]

Question 27

Pleurodesis

Answer 27

Pleurodesis is a medical procedure in which the pleural space is artificially obliterated.[1] It involves the adhesion of the two pleurae.
Pleurodesis is performed to prevent recurrence of pneumothorax or recurrent pleural effusion. It can be done chemically or surgically. It is generally avoided in patients with cystic fibrosis, if possible, because lung transplantation becomes more difficult following this procedure.

Question 28

Pneumonectomy

Answer 28

A pneumonectomy (or pneumectomy) is a surgical procedure to remove a lung. Removal of just one lobe of the lung is specifically referred to as a lobectomy, and that of a segment of the lung as a wedge resection (or segmentectomy).

The most common reason for a pneumonectomy is to remove tumourous tissue arising from lung cancer. In the days prior to the use of antibiotics in tuberculosis treatment, tuberculosis was sometimes treated surgically by pneumonectomy.

The operation will reduce the respiratory capacity of the patient; before conducting a pneumonectomy, the surgeon will evaluate the ability of the patient to function after the lung tissue is removed. After the operation, patients are often given an incentive spirometer to help exercise their remaining lung and to improve breathing function.

A rib or two is sometimes removed to allow the surgeon better access to the lung.

Question 29

Lobectomy

Answer 29

Lobectomy of the lung is a surgical operation where a lobe of the lung is removed.[1] It is done to remove a portion of diseased lung, such as early stage lung cancer.[2]

Question 30

Segmentectomy

Answer 30

In a segmentectomy procedure, a small portion of the lung is removed.

Question 31

Tracheostomy

Answer 31

Among the oldest described surgical procedures, tracheotomy (tray-kee-AH-tow-mee), also known as tracheostomy, consists of making an incision on the anterior aspect of the neck and opening a direct airway through an incision in the trachea (windpipe). The resulting stoma (hole) can serve independently as an airway or as a site for a tracheostomy tube to be inserted; this tube allows a person to breathe without the use of his or her nose or mouth. Both surgical and percutaneous techniques are widely used in current surgical practice.

Question 32

Pulmonary Fibrosis

Answer 32

Pulmonary fibrosis is the formation or development of excess fibrous connective tissue (fibrosis) in the lungs. It is also described as “scarring of the lung”.[1]

Question 33

Pulmonary Fibrosis

Answer 33

Pulmonary fibrosis is the formation or development of excess fibrous connective tissue (fibrosis) in the lungs. It is also described as “scarring of the lung”.[1]

Question 34

Pericarditis

Answer 34

Pericarditis is an inflammation of the pericardium (the fibrous sac surrounding the heart). A characteristic chest pain is often present.

The causes of pericarditis are varied, including viral infections of the pericardium, idiopathic causes, uremic pericarditis, bacterial infections of the pericardium (e.g., Mycobacterium tuberculosis), post-infarct pericarditis (pericarditis due to heart attack; within 24-hours or if weeks-months after: Dressler’s syndrome’s).

Substernal or left precordial pleuritic chest pain with radiation to the trapezius ridge (the bottom portion of scapula on the back), which is relieved by sitting up and bending forward and worsened by lying down (recumbent or supine position) or inspiration (taking a breath in), is the characteristic pain of pericarditis.[2] The pain may resemble the pain of angina pectoris or heart attack, but differs in that pain changes with body position, as opposed to heart attack pain that is pressure-like, and constant with radiation to the left arm and/or the jaw. Other symptoms of pericarditis may include dry cough, fever, fatigue, and anxiety. Due to similarity to myocardial infarction (heart attack) pain, pericarditis can be misdiagnosed as an acute myocardial infarction (a heart attack) solely based on the clinical data and so extreme suspicion on the part of the diagnostician is required. Acute myocardial infarction (heart attack) can also cause pericarditis, but the presenting symptoms often differ enough to warrant diagnosis. The following table organises the clinical presentation of pericarditis:

Question 35

Pericardial Effusion

Answer 35

Pericardial effusion (“fluid around the heart”) is an abnormal accumulation of fluid in the pericardial cavity. Because of the limited amount of space in the pericardial cavity, fluid accumulation leads to an increased intrapericardial pressure which can negatively affect heart function. A pericardial effusion with enough pressure to adversely affect heart function is called cardiac tamponade. Pericardial effusion usually results from a disturbed equilibrium between the production and re-absorption of pericardial fluid, or from a structural abnormality that allows fluid to enter the pericardial cavity.

Normal levels of pericardial fluid are from 15 to 50 mL.

Chest pain or pressure are common symptoms. A small effusion may be asymptomatic. Larger effusions may cause cardiac tamponade, a life-threatening complication; signs of impending tamponade include dyspnea, low blood pressure, and distant heart sounds.

The so-called “water-bottle heart” is a radiographic sign of pericardial effusion, in which the cardiopericardial silhouette is enlarged and assumes the shape of a flask or water bottle.

It can be associated with dullness to percussion over the left subscapular area due to compression of the left lung base. This phenomenon is known as Ewart’s sign.

Pericardial effusion is often related to inflammation of the pericardium that’s caused by disease or injury, but pericardial effusion can also occur without inflammation. Sometimes, pericardial effusion can be caused by the accumulation of blood after a surgical procedure or injury.

Question 36

Pericardiocentesis

Answer 36

a procedure where fluid is aspirated from the pericardium

Question 37

Congestive Heart Failure

Answer 37

congestive heart failure (CHF) or congestive cardiac failure (CCF), occurs when the heart is unable to provide sufficient pump action to maintain blood flow to meet the needs of the body.[1][2][3] Heart failure can cause a number of symptoms including shortness of breath, leg swelling, and exercise intolerance. The condition is diagnosed by patient physical examination and confirmed with echocardiography. Blood tests help to determine the cause. Treatment depends on severity and cause of heart failure. In a chronic patient already in a stable situation, treatment commonly consists of lifestyle measures such as smoking cessation, light exercise, dietary changes, and medications. Sometimes, depending from etiology, it is treated with implanted devices (pacemakers or ventricular assist devices) and occasionally a heart transplant is required.

Question 38

Edema

Answer 38

Edema (American English) or oedema (British English) (/ɪˈdimə/; from the Greek οἴδημα—oídēma, “swelling”[1]), formerly known as dropsy or hydropsy, is an abnormal accumulation of fluid in the interstitium, which are locations beneath the skin or in one or more cavities of the body. It is clinically shown as swelling. Generally, the amount of interstitial fluid is determined by the balance of fluid homeostasis, and increased secretion of fluid into the interstitium or impaired removal of this fluid may cause edema.

Question 39

Patent Foramen Ovale

Answer 39

A patent foramen ovale (PFO) is a hole in the heart that didn’t close the way it should after birth.

During fetal development, a small flap-like opening — the foramen ovale (foh-RAY-mun oh-VAY-lee) — is usually present between the right and left upper chambers of the heart. It normally closes during infancy. When the foramen ovale doesn’t close, it’s called a patent foramen ovale.

Although it’s common to have a patent formen ovale, most people with the condition never know they have it. A patent foramen ovale is often discovered during tests for other problems. Learning that you have a patent foramen ovale is understandably worrisome, but most people never need treatment for this disorder.

Question 40

Left to Right Shunt

Answer 40

A patent foramen ovale (PFO) is a hole in the heart that didn’t close the way it should after birth.

During fetal development, a small flap-like opening — the foramen ovale (foh-RAY-mun oh-VAY-lee) — is usually present between the right and left upper chambers of the heart. It normally closes during infancy. When the foramen ovale doesn’t close, it’s called a patent foramen ovale.

Although it’s common to have a patent formen ovale, most people with the condition never know they have it. A patent foramen ovale is often discovered during tests for other problems. Learning that you have a patent foramen ovale is understandably worrisome, but most people never need treatment for this disorder.

Question 41

Right sided chamber dilation and mycardial hypertrophy

Answer 41

Unhealthy cardiac hypertrophy (pathological hypertrophy) is the response to stress or disease such as hypertension, heart muscle injury (myocardial infarction), heart failure or neurohormones. Valvular heart disease is another cause of pathological hypertrophy. It has also been suggested that the root cause of many heart ailments is cardiac hypertrophy, which in turn is caused by hypoxia due to atmospheric CO, particulate matter, and peroxyl acyl nitrates, which reduces ATP synthesis in cardiac mitochondria.[6][7] Pathological hypertrophy also leads to an increase in muscle mass, but the muscle does not increase its pumping ability, and instead accumulates myocardial scarring (collagen). In pathological hypertrophy, the heart can increase its mass by up to 150%.

Question 42

Ventricular Septal Defects

Answer 42

During ventricular contraction, or systole, some of the blood from the left ventricle leaks into the right ventricle, passes through the lungs and reenters the left ventricle via the pulmonary veins and left atrium. This has two net effects. First, the circuitous refluxing of blood causes volume overload on the left ventricle. Second, because the left ventricle normally has a much higher systolic pressure (~120 mm Hg) than the right ventricle (~20 mm Hg), the leakage of blood into the right ventricle therefore elevates right ventricular pressure and volume, causing pulmonary hypertension with its associated symptoms.

In serious cases, the pulmonary arterial pressure can reach levels that equal the systemic pressure. This reverses the left to right shunt, so that blood then flows from the right ventricle into the left ventricle, resulting in cyanosis, as blood is by-passing the lungs for oxygenation.[4]

This effect is more noticeable in patients with larger defects, who may present with breathlessness, poor feeding and failure to thrive in infancy. Patients with smaller defects may be asymptomatic. Four different septal defects exist, with perimembranous most common, outlet, atrioventricular, and muscular less commonly.[5]

Question 43

Aortic Aneurysim Repair

Answer 43

Endovascular abdominal aortic aneurysm repair is surgery to repair a widened area in your aorta, called an aneurysm. The aorta is the large artery that carries blood to your belly, pelvis, and legs.

The doctor uses x-rays to guide the stent graft up into your aorta, to where the aneurysm is located. The doctor will open the stent using a spring-like mechanism and attach it to the walls of the aorta. Your aneurysm will eventually shrink around it.

Question 44

Pulmonary Valve Stenosis

Answer 44

Pulmonary valve stenosis is a heart valve disorder in which outflow of blood from the right ventricle of the heart is obstructed at the level of the pulmonic valve. This results in the reduction of flow of blood to the lungs. Valvular pulmonic stenosis accounts for 80% of right ventricular outflow tract obstruction.[1] While the most common cause of pulmonary valve stenosis is congenital heart disease, it may also be due to rheumatic heart disease or a malignant carcinoid tumor.[1] Both stenosis of the pulmonary artery and pulmonary valve stenosis are causes of pulmonic stenosis.

Symptoms include jugular vein distension, cyanosis (usually visible in the nailbeds), right ventricular hypertrophy, and general symptoms of lowered oxygenation of the blood. When the stenosis is mild, it can go unnoticed for many years and have no negative symptoms. If stenosis is severe, sudden fainting or dizziness many occur when exercising. An enlarged liver (hepatomegaly) and swelling in the legs (edema) may also be apparent.

Question 45

Pulmonary Valve Incompetance

Answer 45

Pulmonary valve insufficiency (or incompetence, or regurgitation) is a condition where the pulmonary valve is not strong enough to prevent backflow to the right ventricle. If it is secondary to pulmonary hypertension it is referred to as a Graham Steell murmur.The three primary pathological mechanisms causing Pulmonary Valve insufficiency are dilatation of the pulmonic valve ring, acquired alteration of pulmonic valve leaflet morphology, or congenital absence or malformation of the valve.