THE RHYTHM OF THE HEART

Question 1

what does the PR interval represent?

Answer 1

slow conduction through the AV node

Question 2

what does the QRS interval represent?

Answer 2

slow conduction through the ventricular myocardium

Question 3

what does the QT interval represent?

Answer 3

repolaristion of the ventricular myocardium

Question 4

what is the normal PR interval?

Answer 4

<200ms

Question 5

what is the normal QRS interval?

Answer 5

<110ms

Question 6

whats a normal QT interval?

Answer 6

<460ms

Question 7

what is normal sinus rhythm?

Answer 7

regular with a rate of 60-100

Question 8

what is sinus bradycardia?

Answer 8

a sinus rhythm with a resting heart rate of 60 beats per minute or less

Question 9

what is asystole?

Answer 9

when the heart ceases to beat

Question 10

what do you see on an ECG of first degree heart block?

Answer 10

regular QRS complexes but the PR interval is prolonged

Question 11

what do you see on an ECG of second degree heart block type 1?

Answer 11

QRS complexes are not regular

P waves get further away from QRS complex as ventricular rate is slower than atrial rate

Question 12

what do you see on an ECG of second degree heart block type 2?

Answer 12

regular QRS complexes

2 P waves for every QRS

Question 13

what do you see on an ECG of third degree heart block?

Answer 13

regular QRS complexes but these are wide

p waves are totally unrelated to QRS compelxes

Question 14

what is sinus arrest?

Answer 14

cessation of sinus node activity for a short period.

Question 15

what would you see on an ECG in left bundle branch block?

Answer 15

WiLLiaM

Big V in V1 and M in V6

Question 16

what would you see on an ECG in right bundle branch block?

Answer 16

MaRRoW

M in V1 and W in V6

Question 17

what is the treatment for supraventricular tachycardia?

Answer 17

adenosine

Question 18

what does atrial flutter look like on an ECG?

Answer 18

multiple p waves for every QRS

narrow complex tachycardia

Question 19

what does atrial fibrillation look like on an ECG?

Answer 19

chaotic aortic electrical activity

irregularly irregular QRS complexes

Question 20

what would you see on an ECG of Torsades de Pointes?

Answer 20

ventricular tachycardia that looks like twisting points or peaks

Question 21

how do we treat atrial fibrillation?

Answer 21

rhythm control
ventricular rate control
anti-thrombotics

Question 22

what does the CHADS2VASC score tell us?

Answer 22

who would benefit the most from anticoagulation - estimates risk of stroke

Question 23

what are electrical shocks synced to?

Answer 23

QRS complexes

Question 24

how do you treat sinus tachycardia?

Answer 24

Investigate and remove cause. Think about hyperthyroidism, anxiety, heart failure, hypovolemia, septicemia, haemorrhaging etc

Question 25

how do you treat stable supra-ventricular tachycardia?

Answer 25

vagotonic manoeuvres
carotid sinus massag on r carotid
rapid IV adenosine bolus

Question 26

how do you treat stable ventricular tachycardia?

Answer 26

check and correct K+ and Mg+ levels - these will often be low
give IV amiodarone by central line or cardioversion

Question 27

whats more life threatening ventricular tachycardias or supraventricular tachycardias?

Answer 27

ventricular tachycardias