CVS Flashcards
In which week does the embryo fold
4th week
What is the pressures of the atria in utero?
RA pressure > LA pressure
(to allow oxygenated blood to pass through foramen ovale)
What are the remnants of the fetal shunts called?
Fossa ovalis (PO)
Ligamentum arterisoum (DA)
Ligamentum teres (DV)
What’s the membrane resting potential in ventricular myocytes?
-85mV
What channel type is responsible for the uptake of AP in pacemaker cells
L type Ca channels
What effect does hyperkalaemia have on the spread of action potentials?
Cardiac myocytes depolarise inactivating sodium channels so slowing down the spread
What does Ca bind to initiate myocyte contraction?
Troponin C
Adenosine MoA?
Slows down AV node conduction
What is the pressure in the LV if the Left atrial pressure is 5-20 mmHg?
5-20mmHg
Otherwise blood cannot flow there during diastole
Which coronary artery runs through the atrioventricular groove?
Right coronary artery
Where do the L and R coronary arteries arise from?
L and R aortic sinus
What aspect of the heart does the circumflex artery supply?
Left lateral
What structure separates the aorta and pulmonary trunk?
Transverse pericardial sinus
What effect on aBP, CVP & TPR will major blood loss have?
aBP - decreased (less blood in body)
CVP - decreased (less blood in body)
TPR - increased (try to maintain BP)
Which leads for a lateral infarct?
I, avL, V5, V6
Which leads for a anterolateral infarct?
I, aVL, V3, V4, V5, V6
Where would you check for the apex beat?
Left 5th intercostal space, mid-clavicular line
Which muscles help prevent inversion of the mitral and tricuspid valves in systole?
Papillary muscles (via chordae tendinae)
What type of anaemia can aortic valve stenosis cause?
Microangiopathic haemolytic anaemia
What’s a bounding pulse?
When diastolic pressure drops suddenly (strong pulse)
How are SV and EDV linked?
proportional to each other
Which ion flows through HCN channels?
Na
Which ion is responsible for the depolarisation of SA NODE cells?
Ca
What is the name for receptors responsible for Ca induced Ca release?
Ryanodine recpetors
Which 2 parts of the primitive heart form the outflow tract?
Truncus arteriosus and bulbus cordis
(form the aorta and pulmonary trunk)
Why can stasis happen in the LA?
Blood can pool in the left auricle
Define the 3 holes in atrial seperation?
Foramen Ovale - formed by septum secendum
Ostium primum - gap at the bottom of septum primum before it fuses
ostium secondum - hole made at the top of septum primum by apoptosis
What is the most common cause of an atrial septal defect?
Deformation of septum primum/secondum
What features are present in tetralogy of fallot?
Pulmonary stenosis
Overriding aorta
Septal defect (ventricular)
Hypertrophy of RV
(POSH)
Is tricuspid atresia cyanotic or not?
Cyanotic
What is classed as severe hypertension?
Systolic > 180
Diastolic > 110
Which leads look at the Left anterior descending artery?
Septal leads (V1 and V2)
Which leads look at the anterior aspect of the heart?
V3 and V4
Which drug would you give in Wolff parkinson white?
Amiodarone (increases absolute refractory period)
What heart failure is present if the apex is displaced to the left?
Left sided heart failure
What forms the R, L and Inferior border of the heart?
R - RA
L - LV
Inferior - RV
Why could the heart shadow become enlarged?
Dilated LV
Ventricular hypertrophy
Pericardial effusion
Where can the apex beat be felt?
Left 5th intercostal sapce at the mid-clavicular line
What regions of the heart does the LAD supply?
Anterior aspect (LV & RV) and intraventricular septum
What are the changes in the arterial wall which lead to arterial occlusion?
Plaque forms and then ruptures
Thrombus forms which occludes artery
Why is a R coronary artery more likely to cause rhythm disturbance?
Supplies the AV node and SA node
When is the aorta narrowest and widest?
Narrowest - lowest aortic pressure
Widest - highest aortic pressure
Which valves are connected by chordae tendineae? What’s the function?
Mitral and tricupsid valve
Pull the valve flaps taught during ventricular systole so blood doesn’t flow back into the atria
Describe the structures of the pericardial sac?
Outer fibrous layer
Double serous layer:
inner visceral layer
outer parietal layer
What is a complication of cardiac tamponade and what causes it?
A fall in arterial blood pressure due to compression of the heart
Outer fibrous layer cannot expand so this puts extra pressure on the heart providing it from filling properly in diastole
What’s the consequence of a R to L shunt?
LA/LV overload
What 2 things cause the ductus arteriosus to close at birth?
Increased oxygen levels - pressure
Reduction in circulating prostaglandins
Why does a PDA cause LV failure?
LV overload/dilation due to more blood returning to L side of the heart from pulmonary circulation
Define VF
Abnormal rapid ventricular activity with the loss of co-ordinated contraction
How do you measure a patients BP manuallly?
- Inflate cuff while palpating radial pulse
- Inflate to 30 mmHg above where the pulse disappears
- Release slowly, listen to stethoscope over brachial artery
1st Korotkoff sound = systolic BP
2nd Korotkoff sound = diastolic BP
What does hypertension do to the blood vessels?
Atheroma development
Weakening of blood vessels
Where in the body can hypertension be visualised?
Retina
What would tall R waves on ECG suggest?
LV hypertrophy
What would show as a pan-systolic murmur? Which muscle could be effected?
Mitral regurgitation
(papillary muscle)
What is the difference between pericardial effusion and cardiac tamponade?
Tamponade - trauma
Pericardial effusion - Inflammation of pericardium
How do you remember the congenital heart defects?
CYANOTIC (5 Ts)
Tetralogy of fallot
Transposition of great vessels
Truncus arteriosus
Tricupsid atresia
Total anomalous pulmonary venous drainage
ACYANOTIC
(3 HOLES)
ASD
VSD
PDA
(3 BLOCKED PIPES)
Aortic stenosis
Pulmonary stenosis
Coarctation of aorta
What murmur is an aortic stenosis?
Ejection systolic murmur
What murmur is an aortic stenosis?
Ejection systolic murmur
What’s the difference between inotropic and chronotropic?
Inotropic - affecting contractility
Chronotropic - affecting rate
What causes a pan-systolic murmur?
mitral or tricuspid valve regurgitation
Where do the cardiac veins drain into and what does that then drain into?
Into the coronary sinus which then drains into the RA
