Cardiology Basics & DDx

Question 1

which vessel determines dominance in coronary circulation?

Answer 1

PIV (posterior inter ventricular) usually arises from RCA (80%)

Question 2

3 kinds of dominance in coronary circulation

Answer 2

Right 80%
left 15%
balanced 5%

Question 3

SA node supplied by?

Answer 3

RCA 60%

LCA 40%

Question 4

coronaries drain in?

Answer 4

coronary sinus

Thebesian veins: all 4 chambers equally, physiological shunt

Question 5

what’s Kussmaul’s sign, when do you get it?

Answer 5

JVP rises with inspiration instead of falls, get it with pericarditis

Question 6

SA node: how get to left atrium?

Answer 6

Bachmann’s bundle

Question 7

AV node does?

Answer 7

only conducting tract from atria to ventricles due to electrical isolation by annulus fibrosis (unless accessory pathways, WPW)

Question 8

what kind of nerves innervate heart?

Answer 8

sympathetic/parasympathetic

Question 9

what nerves increases heart rate?

Answer 9

beta 1 SA node

Question 10

what nerves increase contractility?

Answer 10

beta 1 in cardiac muscle

Question 11

parasympathetic impact total peripheral vasculature resistance?

Answer 11

not much

Question 12

what does parasympathetic nerves do mostly in heart?

Answer 12

vagal tone dominates SA and AV nodes, slows everything down compare to intrinsic rate

Question 13

causes of true syncope

Answer 13

1. not enough circulating volume
2. obstruction to flow
3. sudden loss of output
4. Reflex

Question 14

examples of obstruction to flow in syncope?

Answer 14

tamponade
PE
pulmonary HTN
Valve stenosis
HOCM

Question 15

examples of sudden loss of output in syncope?

Answer 15

VT
VF
complete heart block

Question 16

what are loss of consciousness NOT due to impaired perfusion?

Answer 16

seizures
hypoglycaemia
hypoxia
psych
CVAs

Question 17

causes of decreased oncotic pressure/hypoalbuminaemia

Answer 17

liver cirrhosis, nephrotic syndrome, malnutrition

Question 18

hormonal causes of generalised oedema?

Answer 18

hypothyroid
exogenous steroids
pregnancy
oestrogen’s

Question 19

most common cause of sinus tachy

Answer 19

1. endocrine (thyrotox, pho, hypo)
   2, systemic (anaemia/fever)
2. drugs (antichol)
3. psych (panic atks)

Question 20

what causes pathological tachycardia?

Answer 20

SVT
Afib
Aflutter
re-entrant SVT
VT

Question 21

cardiovascular cause of dyspnoea

Answer 21

increased pulmonary venous pressure ie:

1. MI
2. CHF/LV failure
3. valve stenosis/regurg
4. arrythmia
5. tamponade
6. pericarditis