Lecture 6: Thoracic Cardiology Flashcards
What separates the superior and inferior mediastinum?
Sternal angle
What makes up the inferior mediastinum?
Anterior
Middle: where heart is
Posterior
What are the layers of the heart?
Fibrous pericardium Parietal serous pericardium Visceral serous pericardium (Epicardium) Myocardium Pericardial cavity Endocardium
What is the function of endocardium?
Separates blood from muscle
What is angina pectoris?
Referred pain down left arm during an MI
What is the most important job of the fibrous skeleton?
- 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
What is the ductus arteriosus?
Before birth, this structure would shunt blood from pulmonary trunk to aorta to bypass non-functional lungs
What is ligamentum arteriosum?
Remnant of ductus arteriosus
- stretched b/t pulmonary trunk and aorta
- weak spot in structure and susceptible to aneurysms
What structure is susceptible to injury if there is aneurysm to the ligamentum arteriosum?
Left Vagus N. and Left Recurrent Laryngeal Nerve
What are atrial septal defects?
Incomplete closure of foramen ovalis
-large holes can allow mixture of oxygen rich and poor blood
What are the three cusps of the tricuspid valve? What is their main general function?
Septal Cusp
Anterior Cusp
Posterior Cusp
Blocks back flow of blood by passively closing during contraction of cardiac muscle
What is the pathways of a cardiac catheter?
IVC Right atrium Right ventricle Pulmonary trunk Pulmonary arteries
What are the two cusps of the bicuspid valve?
Anterior cusp
Posterior cusp
What are the two pericardial sinus?
Oblique and Transverse
What is the significance of transverse pericardial sinuses?
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
What is pericarditis?
Inflammation of pericardium, which can produce friction when beating
What is pericardial effusion?
Inflammation of pericardium can result in accumulation of fluid in pericardial sac, which can compress the heart
What is cardiac tamponade?
Compression of heart
What is pericardiocentesis?
Drainage of fluid from pericardial sac to relieve cardiac tamponade and heart can beat better
Describe the direction of blood flow through the heart:
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
General function of the right and left sides of the heart
Right: carries oxygen poor blood to the lungs
Left: pumps newly oxygenated blood to the body
What is myocardial infarction?
Blockage (embolus) of blood to myocardium usually due to blocked coronary arteries
What is the Foramen Ovalis? How about Fossa Ovalis?
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
What is the role of the right atrioventricular orifice?
Provides passage for blood from the right atrium to right ventricle
What do you call the smooth and rough wall in the Right atrium?
Right ventricle?
Left ventricle?
- Sinus venerum and pectinate muscle
- Conus arteriosus and Trabecula carnae
- Aortic vestibule and Trabecula Carnae
What are ventricular septal defects?
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
What is the role of the aortic valve?
Blocks huge backflow from large aorta so that blood can enter the coronary arteries
Describe the electrical mechanism of the heart
SA Node initiates AP > atrial contraction > AV node waits for the AP > fires and contract the ventricles with the help of the bundle branches
What is the role of a pacemaker?
replaces a defective SA node by sending an AP directly to the ventricle so it contracts
AFib vs. VFib. How would you usually treat these?
Fib = twitching instead of contracting. Resetting the electrical conduction by defibrillation of the heart
