Palpitations/ECG

Question 1

Questions to ask to clarify palpitations?

Answer 1

Onset:

• When and how did it start?
• Sudden vs gradual onset?
• Dehydration, fear, food

Character:

• Fast, slow, or irregular?
• Did you check your pulse at the time?

Timecourse:

• Precipitating/relieving factors (exercise is a red flag)
• Duration
• Resolution - fast/slow, confusion?
• Previous episodes/FHx (e.g. sudden death)

Question 2

Associated symptoms of palpitations

Answer 2

Dyspnoea

Syncope -> seizures/witnesses

Dizziness/light-headedness

Chest pain

Question 3

Differential for irregular fast palpitations

Answer 3

Atrial flutter, atrial fibrillation

Question 4

Important PMHx for palpitations

Answer 4

Rheumatic fever

Angina/IHD

Previous ECG monitoring/angiograms

Diabetes

HTN

Operations (e.g. CABG)

Thyroid function

Valvular heart disease

Question 5

Differential for slow palpitations

Answer 5

Drug-related bradycardias, ventricular bigeminy, heart block

Question 6

Differential for regular fast palpitations

Answer 6

SVTs:

AVNRT (young women, 70% of SVTs)

AVRT: Assoc w/ WPW syndrome

Question 7

Differential for ‘missed beats’

Answer 7

Atrial, ventricular ectopics

Question 8

What is atrial fibrillation?

Answer 8

Irregular atrial rhythm from extranodal depolarisation –> variable conduction through AVN leads to irregular ventricular rhythm

Question 9

What is the main risk/complication of AF?

Answer 9

Embolic stroke

Question 10

Causes of AF?

Answer 10

IHD

Mitral valve disease/rheumatic heart disease

Hypertension

Thyrotoxicosis

Precipitants:

• Pneumonia/endocarditis
• PE
• Caffeine, alcohol, post-op
• Hypokalaemia/Hypomagnasaemia

Question 11

Management of acute AF in unstable patient

Answer 11

DC cardioversion

Question 12

Management of acute AF in stable patient within 48h of onset

Answer 12

Rate OR rhythm control (DC cardioversion or flecainide)

Give heparin if DC cardioversion delayed

Correct underlying

Question 13

Management of acute AF in stable patient >48h from onset

Answer 13

Rate control only!

Need >3wks anticoagulation before rhythm control

Question 14

Pharmacological rate control in AF

Answer 14

Ca channel blockers (non-dihydropiridine, e.g. verapamil/diltiazem not amlodipine)

Beta blockers (e.g. bisoprolol)

Digoxin

Question 15

Rhythm control for AF

Answer 15

Beta blocker

Sotalol

Amiodarone

Flecainide

Electricity

Question 16

Contraindications for flecainide

Answer 16

Structural heart disease (e.g. previous MI)

Ischaemic heart disease

Question 17

Management of chronic AF

Answer 17

Anticoagulate with DOAC (e.g. apixaban) or warfarin

Question 18

Management of atrial flutter

Answer 18

Same as atrial fibrillation!

DC cardioversion preferred

Question 19

Lifestyle risk factors for atrial flutters/arrhythmias

Answer 19

Stress

Caffeine

Alcohol

Nicotine

Question 20

Contraindications of atropine for bradycardia

Answer 20

Mobitz Type II/complete heart block (only affects SAN not AVN)

Long Q-T –> increase risk of ectopics –> torsades de pointes

Question 21

Differential for narrow-complex tachycardia

Answer 21

Atrial flutter, atrial tachycardia

AV nodal reentrant tachycardia (75% of SVTs, younger women)

AV reentrant tachycardia (associated with WPW)

Question 22

Which tachycardia is treated with adenosine

Answer 22

AVNRT (adenosine blocks AVN only!)

Question 23

ECG features of WPW

Answer 23

Short PR interval

Delta wave (slurred upstroke of QRS)

Question 24

Differential of broad-complex tachycardia

Answer 24

Ventricular tachycardia (80% of broad-complex tachys, 95% of those w/ pre-existing heart disease)

SVT + WPW/BBB

Question 25

Initial treatment of broad-complex tachycardia

Answer 25

Lidocaine

Question 26

Differentiating VT from SVT + BBB

Answer 26

LAD, regularity, QRS \>160ms --\> Suggest VT

Question 27

T-wave inversion + palpitations DDx

Answer 27

**LV hypertrophy/LBBB:** Aortic stenosis, HTN **RV hypertrophy:** Pulmonary HTN **Hypertrophic cardiomyopathy** (young patients)

Question 28

What is pre-excited AF?

Answer 28

AF + re-entry circuit (e.g. WPW) --\> Fast + irregular QRS (\>200) --\> predispose to VT/VF

Question 29

Causes of prolonged Q-T syndrome

Answer 29

**Anti-arrhythmic drugs:** e.g. amiodarone, sotalol **Psychiatric drugs:** Tricyclic antidepressants, antipsychotics **Antimicrobial drugs:** macrolides, antimalarials **5 hypos:** Hypothyroid, hypothermia, hypokalaemia, hypocalcaemia, hypomagnasaemia

Question 30

What causes torsades de pointes

Answer 30

QRS ectopic landing on T-wave

Question 31

How do you calculate corrected Q-T interval (should be \<450)

Answer 31

QT/sqrt(RR interval)

Question 32

Management of VT

Answer 32

DC cardioversion Correct K⁺ and Mg²⁺ via central line Amiodarone via central line if refractory

Question 33

Prolonged PR interval

Answer 33

First degree heart block

Question 34

Mobitz Type II block

Answer 34

Form of second degree heart block Some P waves not followed by QRS complexes

Question 35

Leads where T-wave inversion is normal

Answer 35

VR III V1-V2 (V3-V4 in black people)

Question 36

Normal septal Q waves

Answer 36

I, VL, V6 \<1x2mm

Question 37

Causes of LBBB

Answer 37

MI Myocardial fibrosis: HTN/AS/HCM --\> LV hypertrophy

Question 38

Peaked P waves

Answer 38

P ***P***ulmonale RA hypertrophy: Tricuspid stenosis, pulmonary HTN

Question 39

Bifid P waves

Answer 39

M-shaped --\> P **m**itrale LA hypertrophy (mitral stenosis)

Question 40

ECG changes RV hypertrophy

Answer 40

Dominant R wave in V1, deep S wave in V6 RAD Peaked P waves ?T-wave inversion in V1-V2

Question 41

Posterior MI

Answer 41

Dominant R wave in V1

Question 42

T-wave inversion differential

Answer 42

STEMI (if Q waves or ST changes) NSTEMI: no Q-waves/ST changes Ventricularl hypertrophy BBB Digoxin treatment (reverse tick)

Question 43

ECG effects of hypokalaemia/hypomagnasaemia

Answer 43

Flattened T wave Presence of U wave Prolonged PR interval Increased P-wave amplitude

Question 44

ECG effects of hyperkalaemia/hypermagnasaemia

Answer 44

Peaked T waves Prolonged PR interval Flattened P waves Broad QRS complexes

Question 45

Symmetric T-wave inversion in non-coronary distribution

Answer 45

HOCM

Question 46

Causes of raised troponin

Answer 46

MI Myocarditis SVT HF PE Renal failure severe sepsis