physiology

Question 1

what ion channels are involved in depolarisation/excitation?

Answer 1

funny Na+ channel- If
transient T-type Ca2+ channels
long-lasting L-type Ca2+ channels

Question 2

what ion channels are involved in repolarisation/relaxation?

Answer 2

voltage-gated K+ channels

Question 3

on an ECG which leads + vessel correlate for inferior?

Answer 3

II + III + aVF
RCA

Question 4

on an ECG which leads + vessel correlate for anterolateral?

Answer 4

I + aVL + V5 + V6
Left circumflex

Question 5

on an ECG which leads + vessel correlate for anteroseptal?

Answer 5

V2 + V3 + V4
LAD

Question 6

on an ECG which leads + vessel correlate for anterior?

Answer 6

V2 + V3 + V4 + V5 + V6
Left main stem

Question 7

on an ECG which leads + vessel correlate for posterior?

Answer 7

V1 + V2 + V3 reciprocal
RCA

Question 8

what are the causes of right axis deviation?

Answer 8

anterolateral MI
RVH
PE
Lposterior hemiblock
WPW
ASD secundum

Question 9

what are the causes of left axis devation?

Answer 9

inferior MI
LVH
Lanterior hemiblock
WPW
ASD primum

Question 10

what is p mitrale?

Answer 10

bifid p waves = left atrium hypertrophy

Question 11

what can cause p mitrale?

Answer 11

HTN
aortic stenosis
mitral regurgitation
mitral stenosis

Question 12

what is p pulmonale?

Answer 12

peaked p waves = right atrium hypertrophy

Question 13

what can cause p pulmonale?

Answer 13

pulmonary HTN
COPD
tricuspid stenosis

Question 14

what classes a wide QRS?

Answer 14

> 120ms

Question 15

what classes a pathological Q wave?

Answer 15

> 1mm wide and >2mm deep
means full thickness MI

Question 16

what are the signs of RVH on an ECG?

Answer 16

dominant R wave in V1
deep S wave in V6

Question 17

what are the signs of LVH in an ECG?

Answer 17

R wave in V6>25mm
R wave in V5/6 + S wave in V11 >35mm

Question 18

what is a normal PR interval?

Answer 18

120-200MS
(start of P wave to start of QRS)

Question 19

what are the causes of a short PR interval?

Answer 19

accessory conduction eg WPW
nodal rythm
HOCM

Question 20

what is a normal QTc?

Answer 20

380-420ms
(start of QRS to end of T wave)

Question 21

what are the causes of short QTc?

Answer 21

digoxin
beta blockers
phenytoin

Question 22

what are the causes of long QTc?

Answer 22

TIMME
toxines- macrolides, antiarrythmics quinidine, amiodarone, TCAs, histamine antagonists

inherited- romano-ward, jervell
Ischaemia
myocarditis
mitral valve prolapse
electrolytes- low mag/k/ca/temp

Question 23

what leads are T waves normally inverted in?

Answer 23

aVR + V1

Question 24

what are the features of RBBB on an ECG?

Answer 24

maRRow
wide QRS
RSR pattern in V1

Question 25

what are the causes of right BBB?

Answer 25

INCH infarct- inferior MI normal variant congenital- ASD, VSD, Fallot's hypertrophy- RVH- PE, cor pulmonale

Question 26

what are the features of LBBB on an ECG?

Answer 26

wiLLiam wide QRS w notched top t wave inversion in lateral leads

Question 27

what are the causes of LBBB?

Answer 27

FLIC fibrosis LVH- aortic stenosis, HTN infarct- inferior MI coronary HD

Question 28

what are the features of bifascicular block in an ECG?

Answer 28

RBBB + LAD

Question 29

what are the causes of bifascicular block?

Answer 29

RBBB Left anterior hemiblock

Question 30

what are the features of trifascicular block on an ECG?

Answer 30

RBBB + LAFB + 1st degree AV block

Question 31

give examples of narrow complex tachycardias

Answer 31

AVNRT AVRT atrial tachycardia atrial flutter atrial fibrillation

Question 32

give examples of broad complex tachycardias

Answer 32

VT torsades VF