Thoracic Cardiology

Question 1

Divisions of mediastinum and relationships to heart

Answer 1

Superior and inferior mediastinum separated by sternal angle
Inferior mediastinum separated into 3 divisions:
Anterior- anterior to heart
Middle- is the heart
Posterior- posterior to heart

Question 2

Right/left side of heart receive blood from

Answer 2

Right: superior/inferior vena cava- pumps blood to lungs for oxygenation
Left: receives from lungs and pumps to entire body

Question 3

System circulation pathway

Answer 3

From left atrium, past bicuspid valve into left ventricle, out of heart past aortic valve into aorta, through the arterial system, through the capillaries, through the venous system and back into heart through sup/inf vena cava

Question 4

Pulmonary circulation pathway

Answer 4

From superior/inferior vena cava, into right atrium past the tricuspid valve, into the right ventricle, out of the heart past the pulmonary valve into the pulmonary trunk, through the right/left lungs and back into the heart through the pulmonary veins

Question 5

Cardiac layers

Answer 5

Epicardium: outermost layer made of visceral serous pericardium
Myocardium: thick muscular layer made of spiraling, overlapping layers of cardiac muscle
Endocardium: thin internal endothelial and subendothelial layer lining the inside of the chambers of the heart and valves
Fibrous skeleton of the heart: dense collagenous fibers

Question 6

Myocardial infarction

Answer 6

Lack of blood flow to a specific area of the myocardium, usually the result of a blockage in a coronary artery
Coronary atherosclerosis, or a buildup of lipids on the internal walls of the coronary arteries decreases the size of the lumen of that vessel, increasing the likelihood of an embolus, or plug blocking off a vessel entirely

Question 7

Angina pectoris

Answer 7

Pain that originates in the heart and produces a strangling pain of the chest
Angina pectoris literally means strangling pain of the chest
The pain is usually the result of narrow or obstructed coronary arteries that produces ischemia of the myochardium

Question 8

Fibrous skeleton of the heart functions

Answer 8

Produces attachment points for the myocardium and valves of the cuspid valves
Supports and strengthens atrioventricular and semilunar orifices
Provides and electrically insulated barrier b/w the atria and ventricles

Question 9

External surfaces of the heart and their relationship to heart structures

Answer 9

Sternocostal- right ventricle
Diaphragmatic- right and left ventricles
Pulmonary- paired: right atrium and left ventricle, occupying the cardiac impression on both lungs

Question 10

Borders of heart and their relationships to structures

Answer 10

Right: right atrium
Inferior: right ventricle
Left: left ventricle
Superior: right/left atria and the exit point for the aorta and pulmonary trunk

Question 11

Right atrioventricular groove

Answer 11

B/w right atrium and right ventricle

Transmits the right coronary artery

Question 12

Left AV groove

Answer 12

B/w the left atrium and left ventricle

Houses the coronary sinus

Question 13

Anterior interventricular groove

Answer 13

B/w right and left ventricles on anterior aspect of heart

Transmits the anterior interventricular artery and great cardiac vein

Question 14

Posterior interventricular groove

Answer 14

B/w right and left ventricles on posterior surface of heart

Transmits the posterior interventricular artery and the middle cardiac vein

Question 15

Sulcus terminalis

Answer 15

External vertical groove corresponding to the internal crista terminalis

Question 16

Ligamentum arteriosum

Answer 16

Embryological remnant of the ductus arteriosus, which shunted blood from the pulmonary trunk to the aorta to bypass the nonfunctional lungs
Communication b/w the pulmonary trunk and the arch of the aorta

Question 17

Ligamentum arteriosum location and relationship to nerves

Answer 17

Travels from superior pulmonary trunk to inferior border of the aortic arch
The left recurrent laryngeal nerve loops around the aortic arch and ligamentum arteriosum then ascends to the larynx

Question 18

Right atrium structures

Answer 18

Sinus venarum - located posteriorly, where the venae cavae and coronary sinus empty
Pectinate muscle- anterior, contains right auricle
Crista terminalis- internal ridge separating smooth and rough regions
Interatrial septum- wall b/w two atria, contains fossa ovalis (remnant of the foramen ovalis)
Opening for the coronary sinus

Question 19

Atrial septal defects

Answer 19

Typically involves an incomplete closure of the foramen ovale
It is estimated that 15-20% of adults have a small patency of their foramen ovale which is considered clinically insignificant
Larger openings in the interatrial septum can be clinically significant as they allow mixture of oxygen rich and oxygen depleted blood

Question 20

Right atrioventricular orifice

Answer 20

Passage from right atrium to right ventricle, variably occluded by the tricuspid valve

Question 21

Tricuspid valve

Answer 21

Anterior, posterior and septal cusps
Chordae tendinae- attach free edges of the three cusps to the corresponding papillary muscles
Anterior papillary muscle: joined to anterior cusp of tricuspid valve
Posterior papillary muscle: joined to posterior cusp of tricuspid valve
Septal papillary muscle: joined to septal cusp of tricuspid valve

Question 22

Trabecula carnae

Answer 22

Rough muscular region
Contains septomarginal trabeculum: moderator band, from the interventricular septum to the base of the anterior papillary muscle
-transmits the right bundle branch of the AV bundle to the anterior papillary muscle

Question 23

Conus arteriosus

Answer 23

Leads into the pulmonary trunk

Question 24

Pulmonary valve

Answer 24

Semilunar valve possessing right, left and anterior cusps, separates right ventricle from pulmonary trunk
Pulmonary sinuses- space b/w the wall of the pulmonary trunk and the cusps of the pulmonary valve

Question 25

Cardiac catheterization

Answer 25

Insertion of a catheter into the femoral vein which is then passed up to the inferior vena cava allowing radiographic visualization of the right atrium, right ventricle, pulmonary trunk and pulmonary arteries

Question 26

Left atrium

Answer 26

Contains: Left auricle (contains pectinate muscle) Openings for the 4 pulmonary veins Interatrial septum

Question 27

Left AV orifice

Answer 27

Passage from left atrium to left ventricle, variably occluded by the bicuspid valve

Question 28

Bicuspid valve

Answer 28

AKA mitral valve, separates left atrium from left ventricle Anterior, posterior cusps Separates left ventricle from left atrium Chordae tendinae- attaches cusps to ventricular surfaces Anterior papillary muscle: joined to anterior cusp of bicuspid valve Posterior papillary muscle: joined to posterior cusp of bicuspid valve

Question 29

Left ventricle contains:

Answer 29

Bicuspid valve Trabecula carnae- rough muscular region Aortic vestibule- leads into ascending aorta Interventricular septum: myocardial wall separating the two ventricles, houses the AV bundle, right and left bundle branches and subendocardial branches - described as having a fibrous part that belongs to the fibrous skeleton of the heart and much larger muscular part Aortic valve

Question 30

Ventricular septal defects

Answer 30

Due to the embryologically divergent tissues that make up the interventricular septum that structure is particularly susceptible to defects. All defects are clinically relevant as they allow the mixture of oxygen rich and oxygen depleted blood

Question 31

Aortic valve

Answer 31

Semilunar valve possessing right, left and posterior (non coronary) cusps Separates L ventricle from the ascending aorta, occupies the aortic orifice Aortic sinuses- space b/w the wall of the ascending aorta and cusps of the aortic valve, the right and left aortic sinuses house the openings for the right and left coronary arteries

Question 32

Conducting system of the heart

Answer 32

Consists of cardiac muscle cells, specialized conducting fibers and two bundles of nodal tissue responsible for coordinating the cardiac cycle -SA/AV nodes and bundles

Question 33

SA node

Answer 33

Located in myocardium, where the superior vena cava meets the right atrium Small bundle of specialized cardiac muscle fibers that initiate and regulate impulses that propagates through the atrial walls, producing diastole "pacemaker" of the heart

Question 34

AV node

Answer 34

Small bundle of specialized cardiac muscle fibers located in the interatrial septum near the opening for the coronary sinus, responds to the impulse from the SA node that distributed through the wall of the atrium and distributes that signal through the ventricles

Question 35

AV bundle

Answer 35

Crosses the electrically insulated barrier provided by the fibrous skeleton of the heart and distributes the impulse from the AV node into a right/left AV bundle which then distributes as subendocardial branches

Question 36

Subendocardial branches

Answer 36

Distribute the AV nodal impulse from the R/L AV bundle branches first to the interventricular septum, then to the papillary muscles, and finally to the rest of the ventricular wall; also called purkinje fibers

Question 37

Artificial cardiac pacemaker

Answer 37

Produces a regular electrical impulse that is carried to the ventricles via electrodes which are inserted through a large vein to the superior vena cava, into the right atrium past the tricuspid valve into the endocardium of the trabecula carnae of the right ventricle

Question 38

Atrial fibrillation

Answer 38

Irregular twitching of the atrial cardiac muscle fibers to which the ventricles respond at irregular intervals Circulation usually remains satisfactory

Question 39

Ventricular fibrillation

Answer 39

Rapid irregular twitching of the ventricles rendering the heart unable to pump blood. An electric shock administered by electrodes can cease all cardiac movement (defibrillation), in the hopes that the heart may begin beating regularly after a period of time

Question 40

Cardiac referred pain

Answer 40

Ischemia stimulates visceral pain sensory fibers in the heart of the autonomic nervous system These visceral sensory fibers often share a spinal ganglion with the somatic sensory fibers of areas such as the upper limb and superior lateral chest wall Anginal pain is typically referred to the area innervated by the left medial brachial cutaneous nerve, the left substernal area, left pectoral area and medial aspect of the left upper limb are often involved in this variety of referred pain

Question 41

Pericardium

Answer 41

Serous -parietal: adhered to the fibrous pericardium -visceral: adhered to the heart, makes up epicardium Fibrous Oblique pericardial sinus- wide recess posterior to base of heart Transverse pericardial sinus- transverse passage traversing the origins of the great vessels

Question 42

Surgical significance of the transverse pericardial sinus

Answer 42

This space allows cardiac surgeons to access the area posterior to the aorta and pulmonary trunk to clamp or insert the tubes of a bypass machine into these large vessels

Question 43

Pericarditis

Answer 43

Inflammation of the pericardium, which can make the pericardium rough and produce friction This friction called a pericardial friction rub can be observed with a stethoscope If left untreated the pericardium can calcify

Question 44

Pericardial effusion

Answer 44

Inflammation of the pericardium can result in the accumulation of fluid or pus in the pericardial sac which can compress the heart Heart compression is known as cardiac tamponade

Question 45

Pericadiocentesis

Answer 45

Drainage of blood, fluid or pus from the pericardial sac | This is usually done to relieve cardiac tamponade