Cardiovascular Flashcards
Cardiac activation sequence
SA node Internodal tracts Atria AV node Bundle of his Bundle branches Purkinji fibers Ventricular myocardium
What does Right and left coronary arteries supply
RCA -SA nodal branch, AV nodal branch
Right marginal branch -RV
(rhythm disturbances)
LCA = circumflex artery goes around to supply LA and LV
(Pump failure)
Venous blood flow and what happens when there is portal hypertension
Normal flow - stomach –> portal vien –> liver –> IVC –> Heart
Esophagus –> azygous system –> SVC –> heart
If the portal vien/liver is blocked, then blood will have to go back via and up to azygous vien and back to heart (will bypass liver)
-get eosphageal, rectal or umbilical varaciies
Atherosclerosis, Aneurysm, thrombosis, critical stenosis, embolism
Hardening or narrowing or arteries
bulging weak area of artery wall, increased risk of rupture (can get bleeding, and can occur in brain)
Thrombosis - formation of a blood clot inside an artery, obstructing artery
Critical stenosis - narrowing of an artery
Embolus - anything that travels through the blood vessles until it reaches a vessl to small to pass and blood flow is stopped (e.g could be a blood clot) - embolism
Normal blood pressure
Hypertension
120/80
Hypertension - thicker walls (narrower lumen which increases BP)
Atherosclerosis
what is it?
risk factors?
Disease which is hardening or narrowing of large or medium sized arteries (due to plaques - lipid and fibrous tissue)
Risk factors
- hyperlipidemia
- smoking
- hypertensin
- Diabetes mellitus
Protective factors - exercise
Could be due to endothelial cell injury - process due to haemodyanmic force of blood (hypertenison), chemical insults - smoking - cause inflammatory response
Can result in aneurysm and rupture, thrombus, critical stenosis
Venous thrombosis
how is it related to pulmonary embolism
Formation of blood clot that starts in the deep viens of lower leg (DVT)
- due to events that slow blood flow e.g childbirth, trauma, pill
- can break of becoming an embolus and lodge in right heart (pulmonary embolism )
Thrombosis , thrombus
Occurs when haemostasis is activated inappropriately
A thrombus is a mass formed by blood constituents (platelets and fibirn which trap red and white blood cells
-can occur in a blood vessel and may cause further damage by obstructing lumen of vessels where they can break off and travel as an embolus
Virchows Triad
3 main predisposing factors for a thrombosis -
changes in vessel wall, blood flow or constituents of blood
e.g endothelial injury , or hypercoagulability (smoking ect) or
turbulence of blood flow (can be caused by narrowing of the arteries, aneurysms - dilators, abnormal cardiac rhythm.
Ischemia , infarction
ischemia - inadequate blood supply to a tissue
Infarction - necrosis due to tissue death after ischemia
Ischemic heart disease
usually caused by atherosclertoic narrowing of coronary arteries leading to reduce blood flow to heart muscle
-chronic IHD - heart failure
angina pectoris
pain due to heart muscle ischemia, recurrent attacks of chest discomfort - constricting, squeezing ect.
Myocardial infarction
how is it caused, treatment?
slowly growing atherslertotic plaque in coronary artery suddenly enlarges, can occur when plaque ruptures or when a thrombus forms in lumen, result in necrosis to an area of heart
Treatment - anti-thrombolitic agents, re-expansion of occluded vessl, cornoary artery bypass
syncope, palpations
syncope - loss of consciousness (caused by decreased blood to brain - central hypoperfusion)
Palpations - rapid, strong irregular heart beat
When to give thrombolytics/what do they do? and what are some examples
- Given to break down clots
- e.g streptokinase, tenecteplase
- only within 12 hours of onset of chest pain
- cannot do this if just has surgery due to bleeding risk
