Thoracic Cardiology Flashcards
What are the two divisions of the mediastinum and what divides them?
- superior and inferior mediastinum
- divided by the sternal angle
What are the 3 divisions of the inferior mediastinum?
-anterior, middle, posterior
middle = heart
What are the 5 layers of the heart internal to external ?
- endocardium
- myocardium
- epicardium/visceral serous pericardium
- parietal serous pericardium
- fibrous pericardium
What is the endocardium made of?
-internal endothelial tissue and subendothelial layer lining the inside chambers of heart and valves
What are the functions of the fibrous pericardium?
- provide attachment for myocardium
- AV valves
- support & strengthen AV and semilunar orifices
- electrical insulation b/w atria and ventricles
What are the two pericardial sinuses and where are they located?
1) oblique pericardial sinus - wide recess posterior to the base of the heart
2) transverse pericardial sinus - transverse passage traversing the origins of the great vessels
What is the surgical significance of the transverse sinus?
-space allows cardiac surgeons to access the area posterior to the aorta & pulmonary trunks to clamp or insert tubes of a bypass machine into them
Where does the SVC receives its deO2 blood from ?
-posterior thoracic wall, head, neck UE
Where does the IVC receive its deO2 blood from?
-posterior abdominal wall, LE, Liver
Where does the aortic arch send O2 blood to?
head, neck, UE, anterior thoracic wall
Where does the descending aorta send O2 blood to?
-LE, pelvis, posterior thoracic wall, abdomen
What are the external features of the heart?
1) apex - inferolateral LV
2) base - Posterior, near LA
3) Surfaces - >sternocostal - RV
- > diaphragmatic - RV & LV
- > pulmonary - RA & LV on cardiac impressions
4) Borders
- right = RA
- Left -> LV
- inferior = RV
- superior = RA & LA, exit point to great vessels
Where is the Right Atrioventricular groove and what runs in it?
- in b/w the RA & RV
- right coronary A.
Where is the Left Atrioventricular groove and what runs in it?
- in b/w the LA & LV
- coronary sinus
Where is the anterior inter ventricular groove and what runs in it?
b/w LV and RV on anterior heart
-anterior interventricular a. and great cardiac v.
Where is the posterior inter ventricular groove and what runs in it?
b/w RV and LV on posterior heart
-posterior inter ventricular a. and middle cardiac v.
What is the sulcus terminals?
an external sulcus on the RA that corresponds to the internal crust terminals
What is the Ligamentum Arteriosum ?
the remnant of the ductus arterioles (connect palm trunk and aortic arch in fetus & infancy)
What are the Internal Features of the Right Atrium?
- sinus venarum ( vena cavae & coronary sinus empty into)
- pectinate m. (right auricle)
- crista terminalis (internal ridge sep. smooth and rough)
- interarterial septum (fossa ovalis)
- opening for coronary sinus
What causes an atrial septal defect?
consequence?
- failure of closure of foramen ovals
- opening can allow for mix go O2 rich and depleted blood
- 15-20% of adults
What is the Right Atrioventricular Orifice?
-passage way b/e RA & RV occluded by the tricuspid valve
What are the internal features of the RV?
- tricuspid valve
- trabeculae carnae
- conus arteriosus
- pulmonary valve
Describe the parts of the tricuspid valve and how they’re attached to the heart?
-anterior, posterior, and septal cusps attached to anterior, posterior, and septal papillary m. via chordae tendonae
What is the septomarginal trabeculum and what does it do?
- aka the moderator band, part of the trabeculae carnae
- travels from the IV septum to the anterior papillary m.
- transmits electrical signal from AV bundle to the anterior papillary m.
What is the conus arteriosus located?
smooth walled structure, leads into pulmonary trunk
Describe the features of the pulmonary valve
aka semilunar
- right, left, anterior cusps
- separates RV from pulmonary trunk
- has pulmonary sinuses = space b/w cusps of valve and trunk
What is cardiac catheterization?
insertion of a catheter into the femoral v. and passes up to IVC to view RA, RV, Pulmonary Trunk and Pulmonary A.
What are the internal features of the LA?
- thicker walls than RA
- left auricle (pectinate m.)
- openings for 4 pulmonary v.
- interatrial septum
What is the Left Atrioventricular orifice?
passages for LA to LV, occluded by the bicuspid/mitral valve
What are the internal features of the LV?
- thicker walled than RV
- bicuspid valve
- trabeculae carnae
- aortic vestibule
- interventricular septum
- aortic valve
Describe the features of the bicuspid valve and how attached to heart
- seperate LA and LV
- anterior & posterior cusps attached to anterior & posterior papillary m. via chordae tendonae
What is the aortic vestibule?
- smooth walled structure, leading to aortic valuve
- like conus arteriosus of RV
What does the interventricular septum house?
AV bundle , R/L bundle branches, subendocardial (Purkinje) branches
What are the two parts if the IVS?
-membranous and muscular (larger)
Describe the aortic valve features
semilunar, separates LV from aorta
- occupies Aortic Orifice
- R,L,posterior cusps
- aortic sinus = space b/w wall of ascending aorta and cusps
What is a special feature of the aortic sinus?
has openings for the R & L coronary a.s
What is the fibrous skeleton of the heart made of and what are its 3 features?
- dense collagenous fibers
1) provides attachment points for myocardium and valves of the AV/cuspid valves
2) supports & strengthens AV and semilunar orifices
3) provides electrical insulation b/w atria and ventricles
What are the two parts of the pericardium and the sinuses they create?
- visceral and parietal
- oblique and transverse pericardial sinuses
What is the conducting system of the heart composed of?
- cardic m. cells
- conducting fibers
- two bundles of nodal tissue for coordination
Where is the SA node located and what does it do?
- where the SVC meets the RA
- pacemaker
Where is the AV node and what does it do?
- interatrial septum near opening of coronary sinus
- responds to SA node and distributes signal thru ventricles
What is the path of electrical impulse starting in the SA node?
SA node -> AV node-> AV bundle->R/L bundle branches -> subendocardial branches ->interventricular septum->papillary m. -> ventricular wall
What is Atrial Fibrillation?
irregular twitching to the atria fibers to which ventricles respond at irregular intervals
-CIRCULATION IS OK
What is a Ventricular Septal Defect?
a lack of development of the IVS the allows for mix of O2 rich and depleted blood
What is Ventricular Fibrillation?
- rapid irregular twitching of the ventricles
- heart unable to properly pump blood
- defibrillate the heart to stop it in hope the it start beating regularly again
What is an artificial cardia pacemaker?
electrodes inserted into SVC->RA->tricuspid valve->endocardium of trabeculae carnae of RV that produce regular impulse
(replace SA node)
What is cardia referred pain?
pain caused by ischemia that stimulates visceral pain fibers of heart/ANS
-perception of pain due to shared spinal ganglion w/ somatic sensory fibers of UE and superior lateral chest wall
Where is anginas pain referred to?
left medial brachial cutaneous n. ; left substernal area ; left pec ; medial aspect of L UE
What is pericarditis?
inflammation of the pericardium
- can lead to pericardial friction rub
- –> calcification of pericardium if untreated
What is pericardial effusion?
- pericarditis which cause fluid of pus to accumulate in pericardial cavity
- > leads to compression of the heart = cardiac tamponade
What is pericardiocentesis?
drainage of blood, fluid, pus from pericardial sac
-> relieves cardiac tamponade
What is myocardial infarction?
lack of blood flow to an area of the myocardium
- usu. b/c of blocked coronary a.
- caused by : atherosclerosis = build up of lipids on internal walls of a. narrow it (inc. risk of embolus or complete blockage)
What is Angina Pectoris?
pain that originates in heart and produces strangling pain of chest
-result of narrowed of obstructed coronary a. that produces ischemia of myocardium
What is the difference in MI vs Angina?
MI = complete blockage of vessel Angina = partial blockage
