Lecture 6: Thoracic Cardiology

Question 1

What separates the superior and inferior mediastinum?

Answer 1

Sternal angle

Question 2

What makes up the inferior mediastinum?

Answer 2

Anterior
Middle: where heart is
Posterior

Question 3

What are the layers of the heart?

Answer 3

Fibrous pericardium
Parietal serous pericardium
Visceral serous pericardium (Epicardium)
Myocardium
Pericardial cavity
Endocardium

Question 4

What is the function of endocardium?

Answer 4

Separates blood from muscle

Question 5

What is angina pectoris?

Answer 5

Referred pain down left arm during an MI

Question 6

What is the most important job of the fibrous skeleton?

Answer 6

• Myocardium and cuspid valves attach here
• hold openings for semilunar valves
• Provides an electrically insulated barrier b/t the atria and ventricles so they do not contract at the same time

Question 7

What is the ductus arteriosus?

Answer 7

Before birth, this structure would shunt blood from pulmonary trunk to aorta to bypass non-functional lungs

Question 8

What is ligamentum arteriosum?

Answer 8

Remnant of ductus arteriosus

• stretched b/t pulmonary trunk and aorta
• weak spot in structure and susceptible to aneurysms

Question 9

What structure is susceptible to injury if there is aneurysm to the ligamentum arteriosum?

Answer 9

Left Vagus N. and Left Recurrent Laryngeal Nerve

Question 10

What are atrial septal defects?

Answer 10

Incomplete closure of foramen ovalis

-large holes can allow mixture of oxygen rich and poor blood

Question 11

What are the three cusps of the tricuspid valve? What is their main general function?

Answer 11

Septal Cusp
Anterior Cusp
Posterior Cusp

Blocks back flow of blood by passively closing during contraction of cardiac muscle

Question 12

What is the pathways of a cardiac catheter?

Answer 12

IVC
Right atrium
Right ventricle
Pulmonary trunk
Pulmonary arteries

Question 13

What are the two cusps of the bicuspid valve?

Answer 13

Anterior cusp

Posterior cusp

Question 14

What are the two pericardial sinus?

Answer 14

Oblique and Transverse

Question 15

What is the significance of transverse pericardial sinuses?

Answer 15

Space allows surgeons to access area posterior to aorta and pulmonary trunk to clamp tubes of bypass machine into larger vessels
-separate inflow and outflow (arterial and venous ends) of heart

Question 16

What is pericarditis?

Answer 16

Inflammation of pericardium, which can produce friction when beating

Question 17

What is pericardial effusion?

Answer 17

Inflammation of pericardium can result in accumulation of fluid in pericardial sac, which can compress the heart

Question 18

What is cardiac tamponade?

Answer 18

Compression of heart

Question 19

What is pericardiocentesis?

Answer 19

Drainage of fluid from pericardial sac to relieve cardiac tamponade and heart can beat better

Question 20

Describe the direction of blood flow through the heart:

Answer 20

SVC and IVC > Right atrium > Tricuspid valve > Right ventricle > Pulmonary valve > Pulmonary a > lungs > Pulmonary vein > Left atrium > Bicuspid (mitral) valve > Left ventricle > Aortic valve > Ascending aorta > descending aorta

Question 21

General function of the right and left sides of the heart

Answer 21

Right: carries oxygen poor blood to the lungs
Left: pumps newly oxygenated blood to the body

Question 22

What is myocardial infarction?

Answer 22

Blockage (embolus) of blood to myocardium usually due to blocked coronary arteries

Question 23

What is the Foramen Ovalis? How about Fossa Ovalis?

Answer 23

Foramen Ovalis: Another way to bring blood from pulmonary trunk to aorta bypassing the lungs in utero
Fossa Ovalis: name changed to this at birth

Question 24

What is the role of the right atrioventricular orifice?

Answer 24

Provides passage for blood from the right atrium to right ventricle

Question 25

What do you call the smooth and rough wall in the Right atrium? Right ventricle? Left ventricle?

Answer 25

- Sinus venerum and pectinate muscle - Conus arteriosus and Trabecula carnae - Aortic vestibule and Trabecula Carnae

Question 26

What are ventricular septal defects?

Answer 26

Interventricular septum not closed properly due to parts being from different embryological origins -causes mixing of oxygen rich and poor blood, usually worse than atrial septal defects

Question 27

What is the role of the aortic valve?

Answer 27

Blocks huge backflow from large aorta so that blood can enter the coronary arteries

Question 28

Describe the electrical mechanism of the heart

Answer 28

SA Node initiates AP > atrial contraction > AV node waits for the AP > fires and contract the ventricles with the help of the bundle branches

Question 29

What is the role of a pacemaker?

Answer 29

replaces a defective SA node by sending an AP directly to the ventricle so it contracts

Question 30

AFib vs. VFib. How would you usually treat these?

Answer 30

Fib = twitching instead of contracting. Resetting the electrical conduction by defibrillation of the heart