cardioembryology

– Heart, liver, lung, intestines and spleen

primary ciliary dyskinesia has situs inversus totalis (all organs are reversed), they are often said to have Kartagener syndrome

Heterotaxy is the overall term for any left right axis issues involving any organ 

• Dextocardia-- specifically refers to the heart 
• can be isolated or can involve issues with other organs too

• – Dextrocardia (heterotaxia)
• – No looping
• – Cardia bifida

-Left right dyeins: regulate cilia movement-- cilia is prompted to move in the left direction causing signaling molecules to accumulate on the left side. 

Flectin and Pitx are examples of signaling molecules that are heavily concentrated on the left

the tube loops in a c direction towards the left--this is how the atria goes from below the ventricle to being above the ventricles

Vena cava, portion of right atrium

Trabeculated part of atria

• Trabeculated part of ventricles,
• larger portion of left ventricle

• Smooth part of ventricles,
• larger portion of right ventricle

Pulmonary artery and ascending aorta

Ascending aorta, brachiocephalic trunk

Aortic sac, Truncus arteriosus, Bulbus cordis, Primitive ventricles, Primitive atrium, Sinus venosus

• Primitive atrium
• Sinus venosus

• Aortic sac 
• Truncus arteriosus
• Bulbus cordis

innermost layer is the endocardium, jelly, and outermost is the myocardial cells-- all these cells are derived from the splanchinic mesoderm and this is what will cause the endocardial cushioning which is important in septa formation

cardia bifida

the crest is bent caudally so that it goes from the cranial region to the thorax cavity and then laterally so that the two tubes fuse into one

stimulates the production of Nkx2.5 and Gata4 transcription factors which are involved in the production of cardiac specific proteins

Underlying endoderm releases BMP which signals lateral mesoderm on both sides to differentiate into the primary heart field-- they travel to the cranium and form a cardiac crest. The remaining mesoderm near the notochord does not respond to the signals because the notochord will release chordin and noggin which prevent this kind of differentiation

endocardial cells and neural crest cells will both work together to form the endocardial cushion--different than atrioventricular septum where it is only the endocardial cells

arterial catheter is the best method for accuracy but not practical so the gold standard is auscultate

manual--stethoscope is placed on the vessel (auscultate)

Home devices that calculate BP for you (oscillate)

at home, nighttime--you are more likely to get a better read because you are at rest, nerves and white coat syndrome are out of the picture

Systolic presssure is moreso (higher risk) although both are associated

peripheral resistance: as you age your peripheral resistance will increase causing an increase in the diastolic pressure but after a certain age your compliance of the arteries decreases they become more stiff causing the diastolic pressure to decrease

SV and compliance of the arteries-- systolic blood pressure will increase with age

tough because the chronic hypertensive patient has autoregulated to adjust to the higher pressures-- probably constricted so in response to sudden dropped pressure they wont have the ability to perfuse well (decreased pressure + the vasoconstriction)

causes narrowing of the arteries-- and this can cause scarring to kidneys because now they have decreased perfusion

at significant pressures-- endothelial injury causes proliferation of the smooth muscles causing wall thickening-- necrosis due to impaired o2 delivery or from hypertension directly--becomes really leaky and will release fibrin a large protein (fibrinoid necrosis)-- HYPERPLASTIC arteriolosclerosis 

at moderate-- it can cause endothelial damage that is not so severe, slight leakage enough to release small proteins but not to the point of fibrinoid necrosis where you are releasing fibrin yet HYALINE

Cerebral infarction--because of the hypertension, at greater risk for endothelial damage and clotting--can cause ischemia 

• HTN encephalopathy
• Acute Coronary Syndrome
• Preeclampsia

• Aortic Dissection
• Acute pulmonary edema

intra-cerebral bleed--weakens the arteries and causes them to be at greater risk for rupture

> 180/120 with progressive target organ damage

so someone with a systolic of 200 who is sitting and talking to you normally does not have a hypertensive emergency and can be discharged with emphasis on following up with dr.

• • Resistant Hypertension (needing 3+ meds)
• • Onset before puberty
• • Rapid change in BP control
• • Diagnosis below age 30 without obesity/FH

largely associated with Renal disease 

higher plasma renin activity

normally if you have an elevation in the amount of sodium your kidneys do a good job at eliminating the excess-but guyton theory says that in kidney disease states, you are not able to excrete the Na accordingly causing it to accumulate

facial edema, distended neck and chest veins--the superior vena cava drains blood from all the areas of the body from above the diaphragm except the heart

the left brachiocephalic vein-- in adults it is located below the manubrium and the thymus and anterior to the arteries

but in children it lies a little above the manubrium and is susceptible to damage in emergency tracheostomy procedures. Neck is shorter in infants that is why the sternum does not cover the vein

• posterior 1st thoracic vertebra 
• 1st pair of ribs 
• superior border of the manubrium

thrombus causes mechanical blockage to flow but it also causes vasoconstriction further narrowing

stable plaques do not usually cause infarction because they are stable and have time to develop alternate compensation methods like collaterals etc.

unstable plaques are likely to rupture in response to exercise, sympathetic stimulation, etc--and cause thrombosis formation-- thrombosis is dynamic--less predictability

• 
• same as STEMI BUT thrombolytics not given bc greater risk of bleeding-primary motive is to prevent further clotting to avoid a complete occlusion.

Inferior wall MI

• 
• cath lab is primary treatment-- but if no access- thrombolytics like tpa

• aspirin (antiplatelet)
• p2y12 inhibitor (plavix, clopidegrol)
• beta blocker
• statin
• ace inhibitor (to prevent ventricular remodeling)

aldosterone inhibitors can be considered

t-pa

an increase in pressures because the heart loses its ability to contract effectively so all the fluid begins to accumulate--this can lead to eccentric hypertrophy more chronically

thicken the fibrous cap

T1-T5

also will dilate the coronary arteries to bring more blood back to the heart

coronary sinus-- located in the posterior coronary sulcus 

anterior: great cardiac vein: located above the LAD..main tributary of the coronary sinus 

posterior: middle cardiac vein: located above the PDA

phrenic nerve innervates the fibrous and the parietal layers--and any pericardial issue can have referred pain to the lateral neck/supraclavicular region bilaterally because they are present bilaterally

• -Amount of Ca2+ entering the myocytes through L-type channels
• - Number of ryanodine receptors that are activated
• - Ca2+ load of the sarcoplasmic reticulum

At normal heart rates the majority of Ca2+ is pumped outward across the sarcolemma during diastole by the Na+/Ca

• *inhibits the Na+/K+ ATPase
• *decrease in the activity of the plasma membrane Na+/Ca2+ exchanger (NCX)

increased myocardial contraction

increases...the increased stretch will cause an increased affinity for calcium (calcium force graph shifts to the 0 side because at a given amount of Ca release, the affinity will be greater-more binding

Enhanced Ca2+ binding to TnC contributes to the steep slope of the cardiac length-tension curve 

the A band stays the same length 

but the I and H band change and the sarcomere length shortens bringing all the A bands of neighboring sarcomeres closer together

• actin 
• tropomyosin 
• calcium binding spot

myosin and actin overlap--but it is essentially the length of the myosin

• elevated,
• high preload decreased afterload

• -people who have had endocarditis before
• -congenital heart defects
• -prosthetics foreign implants 

this is only really considered for dental procedures and not any other procedures

you want to decrease afterload as much as you can to encourage flow through the aorta and not back into the atria 

• ballooning 
• beta blockers (also given in chronic to reduce afterload?)

a wave occurs because of the atrial contraction which will cause an increase in atrial pressure

while ventricle is contracting, v wave normally occurs-pulmonary veins are giving fluid, but a small wave. this is now going to be increased because more fluid coming in from regurgitation

delayed bc ventricular pressure has to drop below the atrial pressure--you can tell the severity by how quick you hear the snap. Increased Atrial pressure causes the sound to occur earlier because ventricle pressure doesn't have to decrease as much to equal atrial

in instances where the valve is calcified--if it's not calcified you won't hear it 

rheumatic fever

monoclonal light chain antibodies-- can be secondary to MM--chemo best tx

TTR is a protein made in excess by the liver--TAFAMADIS tx--diagnosed with nuclear scan

cytoskeletal proteins like dystrophin and desmin

if you have a history of cardiac arrest or syncope in the past

the right ventricle appears dilated with poor systolic function and is replaced by fat and fibrosis---

tx: ICD even without history of syncope or cardiac arrest bc ventricular arrhythmias= common cause of death

HoCM treatment--reduces excess contractility to decrease the obstruction of the outflow tract

cause is most likely HOcM

ECG and echocardiogram

if needed to determine prognosis and counsel family--use of genetic testing but not immediate

the heart looks normal it is not dilated or hypertrophied but the function is impaired--abnormal relaxation

inflammatory, endocrine, autoimmune, pregnancy, and viral causes--anything that is not related to HTN, valvular dysfunction, or infarction (CAD)

cell to cell junction 

• dilated: cytoskeletal
• hypertrophic: sarcomere

lateral splanchnic mesoderm--the primary heart field becomes your Right atria, left atria and left ventricle

secondary heart field become: Right ventricle, outflow tract and epicardium (outermost layer of the heart)