ECGs: Tachycardias

Question 1

what murmurs cause AF?

Answer 1

mitral stenosis

mitral regurgitation

Question 2

irregularly irregular rhythm should immediately cause you to think

Answer 2

atrial fibrillation

Question 3

pathology of atrial flutter?

Answer 3

AV nodal reentry circuit

Question 4

why is there increased risk of stroke in AF?

Answer 4

disordered blood flow in the atrium causes it to pool and form a clot which can travel to the brain

Question 5

what are the QRS complexes like in atrial flutter?

Answer 5

regular

Question 6

ECG shows a long PR interval with no other abnormalities

Answer 6

1st degree heart block

Question 7

ECG shows an increasing PR interval with each beat followed by a dropped beat

Answer 7

mobitz type 1

Question 8

atria are fluttering at ___bpm in atrial flutter

Answer 8

300

Question 9

what drug can be given to make atrial flutter more prominently seen on the ECG?

Answer 9

adenosine (adeno-SEEN)

Question 10

a narrow QRS is less than ___ms

Answer 10

120

Question 11

broad QRS complexes are generated from…

Answer 11

within the ventricle

conducted with aberrancy (not using the his-purkinje system)

Question 12

a narrow complex rhythm

Answer 12

at or above the AV node

will be using the His-Purkinje system

Question 13

commonest cause of SVT

Answer 13

AV nodal reentry tachycardia (AVNRT)

Question 14

what happens in AVNRT

Answer 14

an ectopic beat signals around the atrium whilst telling the ventricle to beat

Question 15

what does adenosine do?

Answer 15

blocks conduction through the AV node so stops the reentry circuit

Question 16

Tx SVT

Answer 16

vagal manouevres

adenosine

Question 17

difference between AVNRT and atrial flutter?

Answer 17

AVNRT: reentry circuit occurs in the AV node only

flutter: reentry circuit originates in the WHOLE atrium

Question 18

where’s the problem in AVRT?

Answer 18

an accessory pathway AFTER the normal pathway where the signal goes BACK to the AV node

Question 19

adenosine works for AVRT T/F

Answer 19

T

blocks AV node firing so will prevent the signal coming back

Question 20

how to tell if a lead is pointing negative or positive if it’s hard to tell?

Answer 20

look for the sharpest point on the wave (eg sharp point at the bottom would be a negative lead)

Question 21

if patient is clinically unstable and has a SVT what do you do?

Answer 21

defibrillate

Question 22

delta waves indicate…

Answer 22

WPW syndrome

Question 23

what does a delta wave look like and where is it?

Answer 23

QRS complex

1. a slurred upstroke on the QRS
2. short PR interval

Question 24

there is no AV nodal delay in AVRT T or F

Answer 24

T

ventricles can’t relax

Question 25

AF + accessory pathway (eg WPW) =

Answer 25

VF

Question 26

a p wave found within the QRS complex is found in what supraventricular rhythm?

Answer 26

junctional rhythm

Question 27

if a p wave is found within the QRS complex what has happened?

Answer 27

impulse starts in AV node instead of SA node which causes a simultaneous impulse to both the atria and ventricles

Question 28

2 main pathologies behind SVT?

Answer 28

1. AV node reentry eg atrial flutter | 2. accessory pathways eg WPW

Question 29

an ECG that is sinus rhythm but the p wave looks different time is an example of

Answer 29

supraventricular ectopic beats

Question 30

how can you differentiate clinically between SVT and sinus tachycardia?

Answer 30

vagal manoeuvres | adenosine