Pathology of the Cardiovascular System 2

Question 1

Coarctation of the aorta

Answer 1

defined as a constricted aortic segment (congenital)|

The localized constriction may form a shelf-like structure with an eccentric opening or maybe a membranous structure with a central or eccentric opening.

Question 2

The classic coarctation of the aorta is located in the…

Answer 2

thoracic aorta distal to the origin of the left subclavian artery at about the level of the ductal structure.

Question 3

Coarctation of the aorta can cause…

Answer 3

can increase blood pressure in your arms and head, reduce pressure in your legs and seriously strain your heart leading to LVH and possibly heart failure.

Question 4

Treatment of coarctation of the aorta

Answer 4

Surgery may be needed to correct the defect, depending on the severity of the coarctation, and the presence of other congenital defects.

Another option may be a balloon angioplasty or implantation of a stent using cardiac catheterization.

Question 5

Cyanotic heart disease

Answer 5

refers to a group of many different structural heart defects that are present at birth (congenital).

They result in a low blood oxygen level as deoxygenated blood enters the systemic circulation.

Cyanosis refers to a bluish colour of the skin and mucous membranes.

Question 6

Types of Cyanotic heart disease:

Answer 6

Coarctation or complete interruption of the aorta

Ebstein anomaly = The tricuspid valve sits lower than normal in the right ventricle and the tricuspid valve’s leaflets are abnormally formed

Question 7

Hypoplastic left heart syndrome

Answer 7

The left side of the heart (LA, LV and Aorta) are small and underdeveloped and the mitral valve and aortic valve is atretic (unformed and fails to open).

The heart can’t pump enough blood to the body.

The right ventricle, which is only supposed to pump blood to the lungs, pumps blood to the lungs and the body through a connection called a patent ductus arteriosis (PDA).

Babies with HLHS are almost always born with an atrial septal defect (ASD)

Question 8

Patent ductus arteriosis (PDA)

Answer 8

Lets blood reach the aorta and go out to the body from the right ventricle.

Usually, babies don’t need this connection after they’re born so it closes. But a baby with hypoplastic left heart syndrome needs this connection to get blood to the body. Because the right ventricle is pumping blood to the lungs and the body, it is doing extra work.

Question 9

Atrial septal defect (ASD)

Answer 9

This is a hole between the atria that lets blood with oxygen mix with blood low on oxygen.

This way, the blood that the right ventricle pumps out to the body has some oxygen in it.

Question 10

Treatment for HLHS involves…

Answer 10

Give medicine called prostaglandin to keep the ductus open so the right ventricle can continue pumping blood out to the body.

Connecting the superior vena cava and inferior vena cava directly to the pulmonary arteries.

The main pulmonary artery is connected to the aorta and becomes a systemic vessel from a systemic right ventricle.

Question 11

What Causes Hypoplastic Left Heart Syndrome?

Answer 11

HLHS is a birth defect that happens when a baby is growing in the womb. No one knows exactly what causes it, but it could have a mix of causes, including a baby’s genes

Question 12

A baby born with hypoplastic left heart syndrome may have:

Answer 12

fast breathing

blue or grayish coloring of the skin and nails

trouble feeding

low energy and activity

fewer than normal wet diapers

Question 13

Tetralogy of Fallot

Answer 13

combination of 4 heart defects present at birth, includes:

• ventricular septal defect (VSD)
• narrow pulmonary valve
• thickening of the right ventricle
• misplaced aortic valve

Causes oxygen-poor blood to flow out of the heart and to the rest of the body

Question 14

Treatment of Tetralogy of Fallot involves…

Answer 14

patching the VSD and either bypassing the narrowed pulmonary valve with a conduit or ballooning the valve

Question 15

symptoms of Tetralogy of Fallot:

Answer 15

A bluish coloration of the skin caused by low blood oxygen levels (cyanosis)

Tet spells = develop deep blue skin, nails and lips after crying or feeding, or when agitated due to drop in O2 in blood

Shortness of breath and rapid breathing

Poor weight gain

Heart murmur

An abnormal, rounded shape of the nail bed in the fingers and toes (clubbing)

Question 16

Tetralogy of Fallot defect: pulmonary valve stenosis

Answer 16

Narrowing of the valve that separates the lower right chamber of the heart (right ventricle) from the main blood vessel leading to the lungs (pulmonary artery) reduces blood flow to the lungs. The narrowing might also affect the muscle beneath the pulmonary valve. Sometimes, the pulmonary valve doesn’t form properly (pulmonary atresia).

Question 17

Tetralogy of Fallot defect: ventricular septal defect

Answer 17

A hole in the wall (septum) that separates the two lower chambers of the heart (left and right ventricles). The hole causes oxygen-poor blood in the right ventricle to mix with oxygen-rich blood in the left ventricle. This causes inefficient blood flow and reduces the supply of oxygen-rich blood to the body. The defect eventually can weaken the heart.

Question 18

Tetralogy of Fallot defect: misplaced aortic valve

Answer 18

Normally the aorta branches off the left ventricle. In tetralogy of Fallot, the aorta is in the wrong position. It’s shifted to the right and lies directly above the hole in the heart wall (ventricular septal defect). As a result, the aorta receives a mix of oxygen-rich and oxygen-poor blood from both the right and left ventricles.

Question 19

Tetralogy of Fallot defect: right ventricular hypertrophy

Answer 19

When the heart’s pumping action is overworked, the muscular wall of the right ventricle becomes thick. Over time this might cause the heart to stiffen, become weak and eventually fail.

Question 20

Total anomalous pulmonary venous return:

Answer 20

the veins bringing blood back from the lungs (pulmonary veins) don’t connect to the left atrium like usual. Instead they go to the heart by way of an abnormal (anomalous) connection.

oxygen-rich blood does not return from the lungs to the left atrium. Instead, the oxygen-rich blood returns to the right side of the heart. Here, oxygen-rich blood mixes with oxygen-poor blood. This causes the baby to get less oxygen than is needed to the body. To survive with this defect, babies with TAPVR usually have a hole between the right atrium and the left atrium (an atrial septal defect) that allows the mixed blood to get to the left side of the heart and pumped out to the rest of the body.

Question 21

Transposition of the great arteries

Answer 21

The great vessels are transposed so that the aorta arises from RV and the pulmonary valve arises from the LV. A septal defect (ASD/ VSD) or patent ductus arteriosus must be present for survival. Treatment involves surgically switching the arteries.

Question 22

Symptoms of Cyanotic Heart Disease

Answer 22

• blue lips, fingers and toes
• Breathing problems
• Tiredness
• Sweating
• Poor weight gain
• Fainting and chest pain may occur

Question 23

cyanotic defects:

Answer 23

tetralogy of fallot

transposition of the great arteries

result in mixing of blood, obstructed pulmonary blood flow

Question 24

hypothermia

Answer 24

core body temperature of less than 35 degrees centigrade

Question 25

Hypothermia changes seen on the ECG:

Answer 25

Bradycardias, including: - Sinus bradycardia (may be marked) - Atrial fibrillation with slow ventricular response - Slow junctional rhythms - Varying degrees of AV block Osborn wave (J wave) Long QT interval

Question 26

Osborn wave (J wave)

Answer 26

a positive deflection at the J point (negative in aVR and V1). It is usually most prominent in the precordial leads. The height of the Osborn wave is roughly proportional to the degree of hypothermia.

Question 27

Dextrocardia

Answer 27

heart condition characterized by abnormal positioning of the heart. The apex is positioned on the right side of the chest may be associated with the condition situs inversus where other organs are in a mirror image

Question 28

In the more common types of dextrocardia, other heart defects are also present...

Answer 28

* Double outlet right ventricle * Endocardial cushion defect * Pulmonary stenosis or atresia * Single ventricle * Transposition of the great vessels * Ventricular septal defect

Question 29

ECG findings of dexocardia include:

Answer 29

1. Predominantly negative P wave, QRS complex, and T wave in lead I 2. Low voltage in leads V3-V6 (since these leads are placed on the left side of the chest)

Question 30

Modified ECG Procedure for dexocardia:

Answer 30

A standard 12 lead ECG should be performed followed by a second ECG with right sided chest electrodes applied. Limb electrodes should not be reversed. The resultant modified ECG will show normalised R wave progression but with a negative lead I.

Question 31

Aortic valve stenosis

Answer 31

Valve leaflets of not open completely. The area through which blood moves out of the heart to the aorta is narrowed (stenosis) heart must work harder to pump enough blood into the aorta and to the rest of the body extra work of the heart can cause the left ventricle to thicken and enlarge Eventually the strain can cause a weakened heart muscle and can ultimately lead to heart failure and other serious problems may require valve replacement

Question 32

Aortic valve stenosis symptoms

Answer 32

Some people with aortic valve stenosis may not have symptoms for many years. Symptoms generally occur when narrowing of the valve is severe. - An irregular heart sound (heart murmur) - Chest pain (angina) or tightness with activity - Feeling faint - Shortness of breath - Fatigue - palpitations

Question 33

causes of aortic valve stenosis

Answer 33

Congenital heart defect e.g. bicuspid aortic valve aortic valve calcification (calcium deposits can build up on the heart valves) Rheumatic fever (complication of untreated strep throat which can cause scar tissue to form on valve)

Question 34

Aortic valve regurgitation

Answer 34

condition that occurs when your heart's aortic valve doesn't close tightly some of the blood pumped out leaks backward The leakage may prevent your heart from efficiently pumping blood to the rest of your body the left ventricle holds more blood, possibly causing it to enlarge and thicken at first, the larger left ventricle helps maintain good blood flow with more force. But eventually these changes weaken the left ventricle can lead to heart failure and arrhythmias

Question 35

symptoms of aortic valve regurgitation

Answer 35

Shortness of breath Fatigue Heart murmur arrhythmia fainting Chest pain palpitations Swollen ankles and feet

Question 36

causes of aortic valve regurgitation

Answer 36

Congenital heart defect e.g. bicuspid aortic valve aortic stenosis due to calcification aortic valve calcification (calcium deposits can build up on the heart valves) endocarditis (Inflammation of the lining of the heart's chambers and valves) Rheumatic fever (complication of untreated strep throat which can cause scar tissue to form on valve)

Question 37

With hypothermia, the ECG can first show...

Answer 37

artefact due to shivering (uncommon below 32°C )

Question 38

Hypothermia results in a decline in... Hypothermia leads to ECG with...

Answer 38

heart rate and conduction velocity = bradycardia, heart block prolongation of PR, QRS and QT intervals

Question 39

Below 32°C

Answer 39

atrial activation becomes slow and irregular

Question 40

Below 28°C

Answer 40

junctional bradycardia may be seen

Question 41

most specific ECG finding in hypothermia

Answer 41

J wave (Osborn wave) a dome/hump elevation in the terminal portion of the QRS deflection, best seen in left chest leads (the size of the J wave corresponds with severity of hypothermia)

Question 42

ECG features of hypothermia:

Answer 42

Tremor artefact from shivering AF with slow ventricular rate J wave (Osborn wave) Bradycardias, especially junctional Prolonged PR, QRS and QT interval Premature ventricular beats, ventricular tachycardia, ventricular fibrillation (ventricular arrhythmias are most common cause of death in hypothermia) Asystole = absence of cardaic activity (almost flat line)

Question 43

ECG changes of pericarditis:

Answer 43

Saddle shaped ST elevation (concaves upwards) throughout most of the limb leads (I, II, III, aVL, aVF) and precordial leads (V2-6) PR segment depression can be in these leads due to atrial inflammation Reciprocal ST depression and PR elevation in lead aVR (± V1) Sinus tachycardia is also common in acute pericarditis due to pain and/or pericardial effusion

Question 44

Pericarditis

Answer 44

Inflammation of the pericardium secondary to infection, localised injury or systemic disorders producing characteristic chest pain, dyspnoea and serial ECG changes. Pericarditis is a common cause of chest pain, and may mimic the signs and symptoms of myocardial infarction. It is a result of inflammation of the pericardium.

Question 45

dyspnoea

Answer 45

Shortness of breath

Question 46

chest pain associated with pericarditis is...

Answer 46

often retrosternal in nature, pleuritic, and positional (relieved by sitting forward, worse lying flat)

Question 47

in pericarditis widespread ST segment changes occur due to

Answer 47

involvement of the underlying epicardium (myopericarditis)

Question 48

Echo is useful in the early assessment of patients with suspected pericarditis to look for complications such as

Answer 48

pericardial effusion and cardiac tamponade

Question 49

In pericarditis the degree of ST elevation is typically...

Answer 49

modest (0.5 – 1mm)

Question 50

Pericarditis is classically associated with ECG changes that evolve through four stages:

Answer 50

Stage 1 – widespread ST elevation and PR depression with reciprocal changes in aVR (occurs during the first two weeks) Stage 2 – normalisation of ST changes; generalised T wave flattening (1 to 3 weeks) Stage 3 – flattened T waves become inverted (3 to several weeks) Stage 4 – ECG returns to normal (several weeks onwards)

Question 51

Causes of Pericarditis:

Answer 51

Infectious – mainly viral (coxsackie virus); occasionally bacterial, fungal, TB. Immunological – SLE, rheumatic fever Uraemia Post-myocardial infarction or following cardiac surgery (Dressler’s syndrome) Trauma Paraneoplastic syndromes Drug-induced (isoniazid, cyclosporin) Post-radiotherapy

Question 52

Pericardial effusion

Answer 52

collection of fluid within the pericardial sac. most commonly occurs with pericarditis. When the pericardial sac fills, this puts pressure on the ventricles, and compromises their pumping function. This causes problems with circulation. When this occurs, it is known as cardiac tamponade. Tamponade generally comes on very quickly – it is acute heart failure due to compression.

Question 53

ECG features of pericardial effusion

Answer 53

low voltage QRS complexes

Question 54

treatment of pericardial effusion

Answer 54

most pericardial effusions resolve spontaneously In cases of a rapid forming effusion, then tamponade will probably result; and acute treatment would involve pericardiocentesis, and perhaps a drain, just to allow the fluid to escape.

Question 55

Cardiac Tamponade

Answer 55

heart become compressed by excess fluid in the pericardium. Compression causes reduced diastolic filling of the heart, which can cause cardiac arrest.

Question 56

Atrial septal defects

Answer 56

results from incomplete closure of the atrial septum in utero ECG may appear relatively normal PR interval prolonga- tion and first degree heart block may occur in up to 20% of cases QRS complexes may show some right ventricular conduction delay denoted by an rsR1 in V1 Associated mitral valve clefts can occur, leading to mitral regurgita- tion and, if severe, left ventricular hypertrophy

Question 57

Ventricular septal defects

Answer 57

small ventricular septal defects close spontaneously in 50-70% of cases during childhood Generally these are not asso- ciated with any ECG abnormalities - degree of the ECG abnormality is directly proportional to the haemodynamic effect on ventricular function A medium sized ventricular septal defect can exhibit left ventricular hypertrophy and left atrial enlargement A large ventricular septal defect results in biventricular hypertrophy and equiphasic QRS complexes in the mid-precordium known as the Katz-Wachtel phenomenon

Question 58

Coarctation of the aorta

Answer 58

results in left ventricular hypertrophy in 50-60% of asymptomatic children and adults (deep S wave seen in V1) The strain pattern of lateral T wave inversions is seen in about only 20% of asymptomatic children and adults.