6. Thoracic Cardiology (Olinger)

Question 1

Border of mediastinum

Answer 1

Divisions of the Mediastinum: Superior and Inferior Mediastinum are separated by the Sternal Angle.

The Inferior Mediastinum is further divided into Anterior,
Middle and Posterior Mediastinum.

The Anterior Mediastinum is anterior to the Heart.

The Middle Mediastinum is the Heart.

The Posterior Mediastinum is posterior to the Heart.

Question 2

Layers of the pericardium

Answer 2

Visceral serous pericardium, parietal serous pericardium, with pericardial cavity in between. The most exterior layer is the fibrous pericardium.

Question 3

Transverse and oblique pericardial sinuses

Answer 3

The SVC, IVC and pulmonary veins are partly covered by serous pericardium as they enter the heart. This covering is the Oblique Pericardial Sinus (a wide recess posterior to the base of the Heart). The oblique sinus can be entered inferiorly and will admit several fingers, but the fingers cannot pass around the vessels because the sinus is a blind area (cul-de-sac).

A finger can be inserted through the Transverse Pericardial Sinus (transverse passage traversing the origins of the great vessels) where the aorta and the pulmonary trunk leaves heart. This is located posterior to the large vessels, and anterior to the SVC.

Question 4

Heart surfaces

Answer 4

1. Sternocostal (Right Ventricle)
2. Diaphragmatic (Right and Left Ventricles)
3. Pulmonary (Paired; Right Atrium and Left Ventricle, occupying the Cardiac Impression on both Lungs)

Question 5

Heart borders

Answer 5

o Right (Right Atrium)

o Inferior (Right Ventricle)

o Left (Left Ventricle)

o Superior (Right and Left Atria and the exit point for the Aorta and Pulmonary Trunk

Question 6

External grooves

Answer 6

• Right Atrioventricular Groove (between the Right Atrium and Right Ventricle, transmits the Right Coronary A.)
• Left Atrioventricular Groove (between the Left Atrium and Left Ventricle, houses the Coronary Sinus)
• Anterior Interventricular Groove (between Right and Left Ventricles on the anterior aspect of the Heart, transmits the Anterior Interventricular A. and Great Cardiac V.)
• Posterior Interventricular Groove (between Right and Left Ventricles on the posterior aspect of the Heart, transmits the Posterior Interventricular A. and the Middle Cardiac V.)
• Sulcus Terminalis (external vertical groove corresponding to the internal Crista Terminalis)
• Ligamentum Arteriosum (embryological remnant of the Ductus Arteriosus, communication between the Pulmonary Trunk and the Arch of the Aorta)

Question 7

Right Atrium features

Answer 7

o Sinus Venarum (posterior, smooth, thin walled region where the Venae Cavae and Coronary Sinus empty)

o Pectinate Muscle (anterior, rough muscular wall
- Right Auricle

o Crista Terminalis (internal ridge separating smooth and rough regions)

o Opening for the Coronary Sinus

o Interatrial Septum (wall between the two Atria)
- Fossa Ovalis (embryonic remnant of the Foramen Ovalis)

Question 8

Right Atrioventricular Orifice

Answer 8

Passage from Right Atrium to Right Ventricle, variably occluded by the Tricuspid Valve

Question 9

Right Ventricle - tricuspid valve

Answer 9

Anterior Cusp
Posterior Cusp
Septal Cusp

Chordae Tendineae (attach free edges of the three cusps to three corresponding Papillary muscles)

Anterior Papillary M. (joined to the Anterior Cusp of the Tricuspid valve via Chordae Tendineae)

Posterior Papillary M. (joined to the Posterior Cusp of the Tricuspid valve via Chordae Tendineae)

Septal Papillary M. (joined to the Septal Cusp of the Tricuspid valve via Chordae Tendineae)

Question 10

Right Ventricle - Trabecula Carnae

Answer 10

Septomarginal Trabeculum (Moderator Band; from the Interventricular Septum to the Base of the Anterior Papillary M., transmits the right bundle branch of Atrioventricular bundle to the Anterior Papillary M.)

Question 11

Right Ventricle - Conus Arteriosus

Answer 11

smooth-walled, leads into the Pulmonary Trunk

Question 12

Pulmonary valve

Answer 12

Semilunar valve possessing Right, Left and Anterior Cusps, separates Right Ventricle from the Pulmonary Trunk

Question 13

Pulmonary sinuses

Answer 13

Around pulmonary valve. Space between the wall of the Pulmonary Trunk and the Cusps of the Pulmonary Valve

Question 14

Left Atrium

Answer 14

thicker-walled than the Right Atrium:
o Left Auricle (contains Pectinate M.)
o Openings for the 4 Pulmonary V.
o Interatrial Septum

Question 15

Left Atrioventricular Orifice

Answer 15

passage from Left Atrium to Left Ventricle, variably occluded by the Bicuspid Valve

Question 16

Left Ventricle - valves

Answer 16

Bicuspid (mitral) valve, which separates the left atrium from the left ventricle
 Anterior cusp
 Posterior cusp
 Chordae tendineae (attach free edges of the two cusps to ventricular surfaces)
 Anterior papillary m. (joined to the anterior cusp of the bicuspid valve via chordae tendineae)
 Posterior papillary m. (joined to the posterior cust of the bicuspid valve via chordae tendineae)

Question 17

Left Ventricle - Trabecula crane

Answer 17

rough muscular region

Question 18

Left Ventricle - aortic vestibule

Answer 18

smooth-walled, leads into the ascending aorta

Question 19

Interventricular septum

Answer 19

myocardial wall separating the two ventricles, houses the Atrioventricular Bundle, Right and Left Bundle Branches and Subendocardial Branches. Described as having Membranous (Fibrous) part that belongs to the Fibrous Skeleton of the Heart and a much larger Muscular part

Question 20

Interatrial septum

Answer 20

separating the atria, has an oval, thumbprint sized depression, the oval fossa.

Question 21

Interventricular septa

Answer 21

is a strong, obliquely placed partition between the right and the left ventricles. The membranous part of the IV septa is thin and continuous with the fibrous skeleton of the heart. The muscular part is think and bulges into the cavity of the right ventricle d/2 higher pressure in the left ventricle.

Question 22

Location of heart valves

Answer 22

Aortic valve: 2nd intercostal space to right of the sternal border

Pulmonary valve: 2nd intercostal space to the left of sternal border

Tricuspid valve: near left sternal border in 5th or 6th intercostal space

Mitral valve: apex of heart in 5th intercostal space in midclavicular line

Question 23

Roles of the fibrous skeleton

Answer 23

Four bands of Connective Tissue that surround 1) base of pulmonary trunk, 2) aorta, 3) mitral, and 4) tricuspid valves

Functions:

• keeps semilunar valves patent and prevents them from being overly distended
• attachment for leaflet of cusps
• electrical insulator
• consists mainly of protein collagen; a type of glycoprotein found in CT

Question 24

Electrical flow through the heart

Answer 24

SA node
AV node
Bundle of His
Purkinje fibers
--> right and left atrium
--> then right and left ventricles contract

Question 25

myocardial infarction

Answer 25

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

Question 26

angina pectoris

Answer 26

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

Question 27

Cardiac Referred Pain

Answer 27

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. * Left Medial Brachial Cutaneous nerve

Question 28

Ligamentum Arteriosum

Answer 28

Travels from the superior aspect of the Pulmonary Trunk to the inferior concave border of the Aortic Arch. The Ligamentum Arteriosum is the adult remnant of the embryological Ductus Arteriosus which shunted blood from the Pulmonary Trunk to the Aorta to bypass the nonfunctional lungs.

Question 29

Cardiac Catheterization

Answer 29

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 30

Atrial Septal Defects

Answer 30

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.

Question 31

Ventricular Septal Defects

Answer 31

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 32

Artificial Cardiac Pacemaker

Answer 32

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 33

Atrial Fibrillation

Answer 33

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

Question 34

Ventricular Fibrillation

Answer 34

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 35

Pericarditis

Answer 35

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 36

Pericardial Effusion

Answer 36

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 37

Pericardiocentesis

Answer 37

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