Rhythm of the heart

Question 1

Major ions in cardiac myocytes:

Answer 1

Ca2+
Na_
K+

Question 2

Phase 4 of AP cardiac myocyte:

Answer 2

RMP - K+ is moving out of the cell.

Question 3

What causes the rapid depolarisation

Answer 3

Opening of fast voltage Na+ channels

Question 4

What causes plataeu phase?

Answer 4

K+ and voltage gated Ca2+ open

Question 5

How do pacemaker potentials differ?

Answer 5

Slow Ca2+ and Na+ influx. Then L-type Ca2+ open to rapidly let Ca2+ in.

Question 6

Intrinsic rate of SAN

Answer 6

60-100 bpm

Question 7

Bachmann’s bundle =

Answer 7

SAN to atria

Question 8

What spreads electrical impulse rapidly and synchronously though LV and RV

Answer 8

His-Purkinje system

Question 9

What happens when PNS increases?

Answer 9

Slows HR

Question 10

When does PNS increase?

Answer 10

Sleep
Vasovagal syncope
fittness

Question 11

When does PSN decrease?

Answer 11

First seconds of exercise
Heart failure
Atropine

Question 12

First seconds of exercise vs after

Answer 12

First seconds = PSN decrease

After = SNS increases

Question 13

When does SNS increase?

Answer 13

After first min of exercise
Fear
Adrenaline
Salbutamol

Question 14

When does SNS decrease?

Answer 14

Rest and sleep
Beta blockers
Vasovagal syncope

Question 15

P wave =

Answer 15

depolarisation of atria

Question 16

QRS =

Answer 16

depolarisation of venticles

Question 17

PR intervals =

Answer 17

Conduction through AV node

Question 18

PR segment =

Answer 18

time taken to get signal from SAN and AVN

Question 19

Q is depolarisation of

Answer 19

Interventricular septum

Question 20

R is depolarisaiton of

Answer 20

Mass of ventricles

Question 21

S is depolarisation of

Answer 21

Apex

Question 22

QT interval =

Answer 22

Reflects repolarisation of ventricular myocardium

Question 23

Normal PR interval is

Answer 23

<200 m sec

Question 24

< 200msec is equivalent to

Answer 24

<5 small squares

Question 25

1 small square =

Answer 25

0.04 msec | 40 sec

Question 26

1 large square =

Answer 26

0.2 msec | 200 sec

Question 27

Normal QRS complex =

Answer 27

<120 msec

Question 28

<120 msec is equivalent to

Answer 28

<3 small squares

Question 29

QT interval is dependent on

Answer 29

Rate

Question 30

QTc =

Answer 30

Qt interval adjusted for rate

Question 31

QTc = QT interval at

Answer 31

60 bpm

Question 32

How to work out rate of regular ECG

Answer 32

300/RR interval (num of large squares)

Question 33

Bradycardia =

Answer 33

< 60 bpm

Question 34

Regular QRS P wave in front of each Normal AV delay <60 bpm

Answer 34

Sinus bradycardia

Question 35

Irregular QRS P wave not in front of each Abnormal AV delay <60 bpm

Answer 35

Heart block

Question 36

Causes of sinus bradycardia =

Answer 36

Normal, athelete | Over medication

Question 37

What does a patient need after they survive asystole?

Answer 37

Pacemaker

Question 38

Heart block =

Answer 38

Block in the electrical conduction system

Question 39

Causes of heart block =

Answer 39

MI Congenital Meds Surgery

Question 40

What degree of heart block is usually asymptomatic?

Answer 40

First degree heart block

Question 41

First degree heart block ECG:

Answer 41

QRS regular P in front of ever QRS PR interval prolonged

Question 42

2nd degree heart block is broken up into

Answer 42

``` Type 1 (Mobitz I) Type 2 (Mobitz II) ```

Question 43

Mobitz I =

Answer 43

Electrical signals are delayed ore and more with each beat.

Question 44

ECG of mobitz I =

Answer 44

PR interval gets longer and longer QRS irregular P wave present Ventricular rate slower than atrial

Question 45

Mobitz II is also known as

Answer 45

2:1 heart block

Question 46

Mobitz II ECG:

Answer 46

Bradycardia QRS regular 2x P waves for every QRS

Question 47

Third degree heart block:

Answer 47

Atrial and ventriclar contractions completely unrelated. No atrial signals reach the ventricles.

Question 48

ECG of 3rd degree heart block =

Answer 48

QRS complex regular No P wave in front of each QRS Broad QRS

Question 49

Are QRS on 2rd degree hear block broad or narrow?

Answer 49

Broad

Question 50

A form of sick sinus syndrome in which the arrhythmia alternates between slow and fast heart rates. Often associated with ischemic heart disease and heart valve disease

Answer 50

Brady-tachy syndrome

Question 51

How to treat brady-tachy syndrome?

Answer 51

Bradycardia - pacemaker | Tachycardia - meds

Question 52

Management of sinus bradycardia =

Answer 52

Investigate and remove cause | Manage conservatively

Question 53

What can cause sinus bradycardia?

Answer 53

Beta blockers Digoxin Hypothyroidism

Question 54

what can cause heart block?

Answer 54

MI Digoxin Beta blockers Rate-slowing Ca2+ channel blockers

Question 55

What supplies SAN?

Answer 55

Right coronary artery

Question 56

Emergency treatment of heart block:

Answer 56

- Atropine - Isoprenaline - External pacing

Question 57

Atropine =

Answer 57

Stimulates AV node

Question 58

Isoprenaline =

Answer 58

Adrenaline

Question 59

What happens in bundle branch block?

Answer 59

One ventricle contracts before the others

Question 60

WiLLiAM

Answer 60

LBBB W V1 M V6

Question 61

MaRRoW

Answer 61

RBBB M V1 W V6

Question 62

Tachycardia =

Answer 62

>100 bpm

Question 63

Regular QRS, <120 msec | <120 bpm

Answer 63

Sinus tachycardia

Question 64

Regular QRS <120 msec >140 bpm

Answer 64

SVT

Question 65

SVT =

Answer 65

Superior ventricular tachycardia

Question 66

QRS regular | <120msec wide

Answer 66

Ventricular tachycardia

Question 67

Saw tooth ecg

Answer 67

Atrial flutter

Question 68

Tomb stoning ECG

Answer 68

STEMI

Question 69

Treatment for atrial tachycardia =

Answer 69

Adenosine

Question 70

Adenosine =

Answer 70

Slows conduction through AV node

Question 71

Adenosine won't work on

Answer 71

Atrial flutter

Question 72

What will adenosine do with atrial flutter

Answer 72

Will see the flutter waves

Question 73

Commonest sustained arrthymia =

Answer 73

Atrial fibrilation

Question 74

AF can cause

Answer 74

Stroke | Tachy-cardiomyopathy

Question 75

ECG for AF =

Answer 75

QRS complexes not regular QRS complexes irregular No P waves Narrow complex

Question 76

What can cause VF?

Answer 76

Ventricular tachycardia

Question 77

Regular QRS | QRS <120 msec

Answer 77

Ventricular tachycardia

Question 78

Commonly seen in pre-existing bardycardia, especially if given class I anti-arrythmic

Answer 78

Polymorphic VT/Torsades de Pointes

Question 79

Torsades de pointes can be exacerbated by

Answer 79

Low K+ | Low Mg2+

Question 80

Causes of sinus tachycardia =

Answer 80

``` Hyperthyroid Anxiety Heart failure Hypovolemia Septicaemia ```

Question 81

Management of SVT

Answer 81

- Vagotonic manoevers | - Adenosine Iv

Question 82

Management of VT

Answer 82

Check for hypokalaemia, hypomagnesaemia IV amiodarone Electrical cardioversion

Question 83

Amiodarone =

Answer 83

Ca2+ channel blocker

Question 84

Management of atrial fibrilation =

Answer 84

Rhythm control - cardioversion Ventriclar control - betablocker, digoxin, verapamil Anti-thrombotic

Question 85

What score can assess risk of stroke?

Answer 85

CHADS2-VASC

Question 86

What is digoxin used for?

Answer 86

Atrial fibrilation