CVS Flashcards
What are the? 3 class 1 antiarrythmics and how do they affect the AP
1a - lengthens AP
2b - Shortens AP
1c - No effect on AP
What is the molecular action of beta blockers
inhibit AC to decrease ionotropy
What is the MoA of adenosine?
Resets heart by acting on A1 receptors to decresae AC at AVN and increasing K+ conductance.
What is the MoA of organic nitrates?
Dilate coronary artery and venodilate to reduce preload
What is the MoA of NO?
Increase GC –> increased cGMP –> decreased calcium
Draw out the pacemaker AP
See book.
What is the funny current?
Na channel activated by hyperpolarisation
Draw out the cardiac AP
see book
How does the cerebrum ensure adequate circulation?
High cap density, high flow rate, high o2 extraction rate
How is a hypoplastic heart formed?
Pinching shut of endocardial tube
How long should the QRS and PR interval take
QRS - 0.12s
PR - 0.12-0.2s
Name the acyanotic heart defects
ASD, VSD, PFO, PDA, coarctation of aorta
Name the cyanotic heart defects
tetralogy of fallot, tricuspid atresia, transposition of great vessels, hypoplastic left heart
3Ts 1H
State the histology of cardiac muscle
Striations, branching, central nuclei, intercalated discs, gap junctions
What are after depolarisations caused by?
Increased intracellular calcium
Give 3 causes of arrhythmias
Ectopic pacemaker activity, After depolarisations, reentry loops
What is the tetralogy of fallot?
VSD, overriding aorta, pulmonary stenosis, RVH
What is the right and left AV valves called?
MitraL - left
tricuspid - right
Where is the vasa vasorum found?
TA of great vessels
What 3 things can cause 1st degree heart block?
Digoxin toxicity, coronary artery disease, electrolyte imbalance
What is the result of coarctation of the aorta/
increased pressure –> LVH
What receptor and neurotransmitter is responsible for increasing and decreasing HR?
Increase HR - NA on alpha2
Decrease HR - ACh on M2
What is cushings reflex?
Increased ICP –> decreased blood flow –> Increased sympathetic action to restore blood flow
Where do the baroreceptors transmit their signals to?
medulla oblongata
Name the pressures found in the RA, LA, LV, RV, PA, Aorta
RA - 2, RV - 20,
LA - 5, LV - 120,
PA - 20/10, aorta - 120/80
How does ischemia lead to vasodilation?
build up of metabolites e.g. H+, co2, adenosine
What effect does alpha 1 receptors have?
vasoconstriction
What effect does M3 receptors have?
airways and pupil contraction
What is the average stroke volume?
80 ml
How do you increase the sound of S1 and S2?
S1 - expiration
S2 - inspiration
What is the purpose of the fibrous skeleton of the heart?
provides attachments for cusps and electrical insulation
When is alpha and beta thalassemia detected?
alpha - before birth
beta - after birth
What are the 3 types of arteries?
elastic - aorta and PA. Vasa vasorum
muscular - lots of smooth muscl
arterioles - thin TI
What are the layers of the pericardium?
fibrous and serous (parietal and visceral)
Draw the arteries and veins of the heart
see book.
How would you investigate a coronary artery blockage?
angiogram
what is the fossa ovalis?
remnant of FO
What are the muscles in the interior of the ventricles and atria called?
ventricles - trabeculae carnae
atria - pectinate
What muscles attach to the chordae tendinae? What is their purpose?
papillary - prevents cusps prolapsing
What is eisenmenger syndrome?
Left to right shunt –> increased pulmonary pressure –> right to left shunt
Explain how smooth muscle contracts
increase in calcium –> activated CaM –> activating MLCK –> phosphorylates mysoin heads
Draw out the JVP wave form
see book
What nerve innervates the pericardium
phrenic
define shock
circulatory failure with generalised lack of oxygen
What is cardiogenic shock + give example
failure of heart to pump blood e.g. arrhythmia
What is mechanical shock? How would you treat/
cardiac tamponade. 5th intercostal space left sternal edge aspiration or subxiphoid approach
How do you treat angina?
nitrate spray, beta blockers, CCB, statins, ACEi, stent
What would show on an ECG if someone had a previous MI?
pathological Q waves
How do you diagnose angina?
history, stress test on treadmill (look for ST depression)
What are the signs of left and right HF
left - tachy, fatigue, S3/S4, oedema
right - fatigue, ascites, increased JVP, anorexia
What is S3 caused by? How does it sound? Is it always abnormal?
Can be normal in children and athletes
caused by increased ventricular filling e.g. in HF, mitral regurg, VSD, dilated cardiomyopathy
Sounds like Kentucky
What is S4 caused by? How does it sound? Is it always abnormal?
always abnormal
Caused by ventricular stiffness and forceful contraction of atria to overcome this e.g. in LVH, fibrosis of ventricle
Tennessee
