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Flashcards in Cardiology Deck (148)
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1

ECG signs of firs degree block, second degree and third degree heart block

1 = PR interval > 0.2 seconds

2.1 = Increasing delays until dropped
2.2 = Intermittent drops, in a ratio

3 = Complete dissociation

2

ECG signs of RVH vs LVH?

RVH = Tall R wave in V1, deep S in V6
e.g. cor pulmonale

LVH is Deep S in V1, tall R in V6
e.g. HTN, aortic stenosis and co-arctation

3

Causes of long QT?

TIMME

Toxins e.g. macrolides / amiodarone
Ischaemia
Myocarditis
Mitral valve prolapse
Electrolyte = Low K/Ca/Mg

4

Short QT causes?

Digoxin, BB, phenytoin

5

What is a trifasicular block and when do you see it?

1st degree heart block with LAD and RBBB

Commonly presents as falls in the elderly

6

What is p pulmonale and p mitrale?

Pulmonale = Peaked p wave in RAH e.g. Pulmonary HTN or tricuspid stenosis

P mitrale = Broad bifid p wave in LAH = mitral stenosis

7

ECG changes in VT?

No p waves or T waves. Regular broad QRS

8

ECG changes in Brugada syndrome?

RBBB and coved ST elevation in V1-V3

9

Digoxin ECG changes?

Reverse tick = down sloping ST segment and T-wave inversion

10

ECG changes in hyperkalaemia vs hypokalaemia?

Hyper = Tall tented t waves, wide QRS and absent/flat p-waves

Hypo = Small T waves, ST depression. Prolonged QT and prominent U waves

11

Causes of bradycardia?

DIVISION

Drugs e.g. CCB, BB, amiodarone

Ischaemia

Vagal hypotonia e.g. athletes

Infection e.g. infective endocarditis

Sick sinus syndrome = damage to the SAN / AVN or conducting tissue

Infiltration e.g. sarcoidosis

O's = hypothyroid, hypokalaemia

N = neuro = raised ICP

12

Investigations of bradycardia?

ECG, bloods (cardiac enzymes), event monitor and exercise testing

13

Management of bradycardia?

Unstable = Atropine 0.5mg IV bolus, repeat 3mg max

If refractory can use pacing if:
-Complete heart block, systole, mobitz type 2 or ventricular pause > 3 seconds
- transvenous pacing = lead into RV, only for a few days. Mechanical tricuspid is CI



Stable:
Mild = treat underlying cause + theophylline 200mg PO BD

Severe = Treat and temporary dual chamber pacing

14

Definition of narrow complex tachycardia?

Rate >100BPM, QRS <120ms

15

2 types of narrow complex tachycardias?

AV independent:
- Sinus tachy
- Atrial tachycardia = different focus takes over from SA node
- atrial fibrillation
- flutter = macro re-entry rhythm, atria rhythm of 300 (ventricles can't conduct 300 so P:QRS is usually 2:1)

AV node dependent:

- AVNRT = within node so activates atria and ventricles simultaneously

-AVRT = large accessory pathway e.g. WPW bundle of Kent :
+ Can be orthodromic = down AV node and back round up accessory pathway into atria. p follows each QRS, delayed RP interval

+ can be antidromic = conducted down accessory pathway, and re-enters atria via retrograde flow = broad QRS

16

Management of unstable narrow complex tachycardia?

ABC
DC cardio version x 3
Amiodarone 300mg IV over 10 minutes
Repeat shock
Amiodarone 900mg over 24 hours

17

management of stable narrow complex tachycardia?

Irregular = treat as AF:
- Rate with BB/CCB + digoxin
- anticoagulate
- onset <48 hours = cardioversion

Regular:
- Vagal manouvres
- Adenosine 6mg IV bolus, then 12 then 12. (Use verapamil in asthmatics) If it is AV dependent the adenosine will stop the arrhythmia as it cause AV block.
If it doesn't work means independent = Flutter, AF or ST

18

Management of atrial tachycardia and atrial flutter?

AT:
1st line = Diltiazem or Verapamil
2nd line = amiodarone
3rd line = Flecainide
Refractory = ablation

AF:
Unstable = DC cardiovert

Stable = BB e.g. metoprolol 5mg bolus, repeating up to 3 times
- Amiodarone if refractory
Then cardiovert if refractory (electrical or medical with ibutilide)

For ongoing can ablate the tricuspid isthmus if symptomatic, or asymptomatic give Metoprolol

19

What drugs should you avoid in WPW?

Verapamil and digoxin

20

Definition of brand complex tachycardia?

>100 BPM, QRS > 120ms

21

Classification of broad complex tachycardia?

Most are ventricular:
- monomorphic = single form QRS
- Polymorphic
- Fascicular = Arise from LV with re-entrant into Purkinje's = Sensitive to verapamil
- RV outflow tract tachy = Due to cAMP activity = uniquely sensitive to adenosine
- Torsades des pointes = type of polymorphic

Some are SVT's with aberrant conduction

22

Ventricular tachycardia causes?

MILDE

Myocarditis
Infarction
Long QT: TIMME
Dilated cardiomyopathy
Electrolytes low K/Mg/Ca

23

Management of unstable VT?

ABC
DC cardioversion x 3
Amiodarone 300mg IV over 10-20 minutes
Repeat shock
Amiodarone 900mg over 24 hours

24

Management of torsades des pointes?

In line with ACLS guidelines for unstable VT.
+ usually due to low potassium / magnesium so aggressively replenish

magnesium sulphate 1-2g IV single dose
KCL max 60mM

25

Management of stable broad complex tachycardia?

Correct electrolyte balance
Anti-arrhythmics:
- Amiodarone 150mg bolus then 1mg/min for 6 hours then 0.5mg/min for 18 hours
- 2nd line = lidocaine

Ongoing:

Implanatble cardioverter defibrillator if = Cardiomyopathy, previous VT/VF or congenital arrhythmia problem e.g. Long QT
Anti-arrhythmics e.g. Metoprolol 50mg PO BD

26

What is atrial fibrillation?

Supraventricular tachyarrhythmia, with an irregularly irregular rhythm.

Abnormal atria promoting electrical re-entry

27

How do we classify atrial fibrillation?

First diagnosed = new diagnosis regardless of duration

Paroxysmal = self terminating, usually within 2 days

Persistent = longer than 7 days, including episodes cardioverted post 7 days

Long standing = continuous > 1 year, have adopted rhythm control

Permanent = No rhythm control

28

Causes of atrial fibrillation?

Cardiac = HTN, LV failure, ischaemic heart disease

Non-cardiac = thyrotoxicosis, pulmonary e.g. PE, drugs and alcohol

29

Management of unstable AF?

Unstable = DC cardiovert, if >48 hours must do a TOE to exclude atrial thrombus

30

Management of Acute AF?

If >65 or Hx of IHD = RATE control:

without heart failure - metoprolol 5mg bolus, repeat up to 3 times then regular metoprolol 50mg PO BD
If asthmatic use diltiazem

Heart failure = use digoxin 0.5mg PO OD

If <65, symptomatic, first presentation, lone AF / secondary to corrected precipitant = RHYTHM:
- <48 hours = immediate cardioversion
+ DC cardioversion with amiodarone therapy 4 weeks prior and 12 months after
+ Flecainide single dose 200mg
+ If evidence of structural heart disease use amiodarone

>48 hours = establish INR of 2-3 for 3 weeks prior to cardioversion