1,000ft view Cardiology Flashcards
What is the size of the heart
same size as a closed fist
base= superior portion
apex = point
where is the atria located
primarily posterior between the lung hila
what is medial sternal widening
width between the lungs is wider on x-ray
aortic dissection until proven otherwise
what are the layers of the wall of the heart
pericardium
epicardium
myocardium
what is the pericardium
parietal layer is the outer aspect, helps to anchor to surrounding structure. contains serous fluid to prevent inflammation
what layer of the heart wall is adhered to the heart, smooth, transparent and slipper
Epicardium
what is the myocardium
cardiac muscle
what is the endocardium
smooth linking for the chambers and valve
continuous blood vessel endothelium
what is endothelium
thick connective tissue linking the inner ascpect of the heart
what type of cells is the heart made of
contractile, involuntary, striated muscle cells
- slower than skeletal muscle
- plateau phase
excitatory and conductive muscle fibers - automatic rhythmical electrical stimulation on the cardiac muscle cells
what is the plateau phase
allows blood to move the way it needs to move throughout the heart
how are cardiac muscles aranged
branching networks rather than parallel to one another
What are the junctions between cardiac muscle cells
intercalculated discs
what is the purpose of intercalculated discs
allows for rapid transmission of cellular activity via gap junctions and electrical conduction
what is released when action potential is triggered
calcium
What are the specific cardiac muscle troponins
Troponin I and Troponin T
protein is released during ischemic event and can be detected in blood
what is the timing for troponin level changes s/p MI
will elevate within 3 hours
how long does cTnT remain elevated
7-14 days
how long does cTnI remain elevated
10-14 days
what contracts during diastole
atria to forcefully propel blood into the ventricles
What does the fibrous skeleton allow
the ventricular and atrial contraction/depolarization to remain separate and keep passage of ions from transmitting to one another
what are the two types of septum within the heart
Interatrial septum
intraventricular septum
What are valves within the heart made up of
dense connective tissue - covered by endocardium
what are the atrioventricular valves
Tricuspid valve
Mitral valve
what are the semilunar valves
Pulmonic and aortic valves
What attach the AV values to the Ventricular walls
chordae tendineae
What is the normal generator of cardiac electrical conduction
sinoatrial node
what passively fills the right atria
SVC and IVC
and receives blood from the venous blood from coronary vasculature via the venous sinus.
what is the tricuspid valve
3 leaflet valve encased in endothelium
opens when atrial pressures are greater than ventricular
closes when ventricular pressures are greater than atrial
closes very easily with minimal back-flow of blood
fairly soft closure
What are the different pressures of the right and left atria
Right increases 4-6mmHg
Left increases 7-8mmHg
what part of the heart is the low pressure system
right part of the heart
what part of the heart receives deoxygenated blood
right atria and ventricle
what is the pulmonic valvue
semilunar valves
connects the RV with the pulmonary trunk
snaps shut during beginning of diastole
how does the left atria receive blood
from the right and left pulmonary veins
what is attached to the left atria
left atrial appendage
what is the mitral valve
2 leaflet valve (bicuspid valve), encased in endothelium
what is the thickest part of the myocardium
left ventricle: needs to push against systematic vascular resistance
what is the end of diastolic volume
left ventricle: fills with 110-125mL of blood
relaxation part before contraction
what is the pattern of left ventricular contraction
twist in a wringing motion with the inner, subendocardial, layer twisting rightward and outer, subepicardial, layer twisting leftward
causes base to be pulled downward during systole will untwist during diastole
what opens during ventricular contraction (systole)
aortic valve
what artery feeds the heart itself with blood
coronary artery
What is the P wave
atria contraction / depolarization
what is the QRS complex
ventricular contraction / depolarization
what is a Q wave
downard deflection
what is the RS complex
ventricular depolarization complete
what is the pause between P and Q wave called
AV node pause - isometric
what is the T wave
ventricular depolarization begins at the apex and pregresses superiorly
(resetting)
what is the pause between S and T waves
plateau phase - pause before repolarization
when do coronary vessels fill
during diastolic relaxation
what determines coronary vascular resistance
hormones
neural stimulation
metabolic demand
peripheral vascular resistance
what does the right coronary artery do
supply the right atrium and right ventricle
what does the left circumflex artery do
supplies the left atrium and left ventricle
what does the left anterior descending artery do
supplies the right ventricle, left ventricle and interventricular septum
what does the left marginal artery do
supplies the left ventricle
what are the left coronary artery branches
left circumflex and left anterior descending
what is key about the right coronary artery
conduction system
systole
squeezing
diastole
relaxation - filling
what valves are open during diastole
Tricuspid and Mitral valves - AV valves
from the SA node - where does the stimulation go to
Travel along intranodal pathway to right atria and Bachman bundle to left atria
how long is the pause at the AV note
0.12 second pause
what is the ejection fraction
at the end of diastole
during contraction about 60% ejected
about 70mL from each of the ventricles into either pulmonary or systemic circulation
how much blood remains in the ventricles after contraction
40-50ish mL remains
how is ejection fraction measured
via ultrasound
what valves open during systole
Pulmonic and Aortic valves (semilunar valves)
where is a majority of the blood within the body
within the capillaries
What is the formula for cardiac output
stoke volume + heart rate = Cardiac output
what makes up the stroke volume
blood volume and vascular resistance
what is preload
pressure that fills the ventricles - diastolic measurement
BP in the LV right before ventricular contraction begins
what is afterload
the resistance the left ventricle needs to push against
systemic vascular resistance
what type of vasculature has greater amounts of tunica media
artery
what valves close during S1
AV values close and systole begins
what valve closes during S2
semilunar valves close and diastole begins
what can falsely elevate troponin levels
renal failure
when do we draw troponin levels
chest pain concerning for Acute Coronary Syndrome (ACS)
cardiac strain
CHF
what is CPK-MB
creatine phosphokinase MB
creatinine kinase is enzyme that is found within the heart, skeletal muscle and brain
takes longer to elevate, returns back to normal earlier than troponin
What is a BNP
B-type natriuretic peptide - hormone that was initially identified in the brain, diuretic and hypotensive effects
typically from cardiac ventricle - rate of elevation correlates with degree of heart failure
elevated with HTN, CHF, and atherosclerosis
