Arrhythmias

Question 1

Associated risk factors of AF

Answer 1

Increasing AGE greatest risk factor
M > F
HTN, Valvular HD - MS+++, HOCM, Hyperthyroidism, Obesity, DM

Question 2

What is the associated increased in all cause mortality from AF. Why?

Answer 2

1.5-2x increase in mortality

Due to stroke and other thromboembolic disease, heart failure

Question 3

Pathogenesis of AF

Answer 3

Left atrial stretch
Increase risk with family history
Inflammation
Metabolic syndrome

Question 4

AF mechanisms

Answer 4

1st stage: Arrhythmic foci extending into the pulmonary veins –> recurrent paroxysmal AF lasting <24hrs

2nd stage: Arrhythmic burden +/- other cardiac factors –> remodeling –> persistent AF

3rd stage: Gross electrical and structural remodeling –> permanent AF

Question 5

Management of new onset AF <48hrs

Answer 5

REVERT!!!
TTE, Renal functions and TFTs should be done
Anticoagulate as per CHAD2S

Question 6

Management of AF >48hrs/???

Answer 6

TOE, revert and anticoagulate for at least 6 weeks

Anticoagulate for 4-6 weeks then revert

Question 7

? Urgent Cardioversion?

Answer 7

Unstable patient haemodynamics

Question 8

Sinus rhythm maintenance for paroxysmal AF?

Answer 8

Sotalol - MAINTENANCE NOT REVERSION. Causes fatigue
Amiodarone - Effective BUT SIDE EFFECTS = Thyroid, pulmonary, hepatic and occular
Flecainide - Very effective at reverting. Can’t use in pts with structural heart disease. Side effects of GIT and dysthesias, and can cause A flutter

Question 9

Rate Vs. Rhythm control

Answer 9

Not relevant to recent AF
Not relevant to symptomatic AF
Not relevant to anticoagulation
PERSISTENT ASYMPTOMATIC AF- AFFIRM trial

Question 10

AF Rate control agents?

Answer 10

Beta blockers
Calcium calcium blocker- NOT IN HF
Digoxin
Aim <110 bpm

Question 11

AF Ablation?

Answer 11

For symptomatic AF refractory to meds
60-70% successful
Does not improve outcomes

Question 12

Mechanism of atrial flutter

Answer 12

Macro re-entrant circuit in the RA between the IVC and tricuspid valve
Counterclockwise motion –> downward p waves in ii, iii and aVF

Question 13

Treatment for Atrial Flutter?

Answer 13

Ablation
Success in 90%
Anticoagulate as per AF

Question 14

Risk stratification for anti-thromboembolism therapy?

Answer 14

CHADS2
CCF =1
HTN =1
Age >75yrs =1
DM =1
Previous stroke =2

Score of 0 = nothing
Scores 1-2 = 2% risk = anticoagulate
Scores 3+ = 4% risk = anticoagulate

Question 15

Anticoagulate with what?

Answer 15

NOAC or Warfarin
Not aspirin
No NOAC for valvular heart disease

Question 16

AV nodal reentry tachycardia

Answer 16

2 conduction pathways in the AV node with the slow pathway blocked by the refractory period
When a premature complex occurs –> conduction through the slow pathway –> retrograde p wave –> tachycardia

Question 17

Prevention of AVNRT

Answer 17

Verapamil

EPS

Question 18

Treatment of AVNRT

Answer 18

Vagal maneuvres
Adenosine
CCBs
B blockers

Question 19

Different manifestations of WPW

Answer 19

1. Accessory pathway
2. Orthodromic tachycardia - long QRSP. Down slow and up fast
3. Antidromic Tachycardia = wide complex tachycardia - looks like VT. Down fast pathway and up slow pathway –> Torsades

Question 20

Investigation of WPW

Answer 20

Exercise test to assess pathway conduction. Loss of delta wave <130bpm is predictor of low risk

Question 21

Different kinds of VT

Answer 21

1. Associated with structural HD - post MI, ischaemic and non-ischaemic cardiomyopathy, myocarditis and infiltrative cardiac diseases
2. Not ass. with structural heart disease

Question 22

Treatment of VT with structural heart disease

Answer 22

= AICD!!!

Question 23

Primary prophylaxis with IHD

Answer 23

Post AMI = beta blockers –> reduction by 30%

AICD for EF <35% >40 days post AMI.

Question 24

Primary prevention in non-ischaemic cardiomyopathy

Answer 24

Optimise medical therapy
Beta blockers
CRT for QRS >120ms
CRT for class 4 heart failure

Question 25

Commonest cause of SCD <35yrs

Answer 25

HOCM

Question 26

Diagnosis of HOCM

Answer 26

ECG !!! Inverted T waves V4-V6. Still negative in 10% Genetic tests - genes found in 60% of cases = used to screen other family members

Question 27

? AICD for HOCM Average risk .05% but range from 0-10%

Answer 27

``` Family hx of SCD Unexplained syncope nsVT on monitoring IVS> 30mm Abnormal BP during exercise ```

Question 28

Arrhythmogenic RV cardiomyopathy genetics

Answer 28

Mutations in genes coding desmosomal proteins Identified in 40-60% Not diagnostic - incomplete penetrance

Question 29

Diagnosis of Cardiac Sarcoidosis

Answer 29

Cardiac MRI | Aneurysms and enhancements

Question 30

Genetics of long QT syndrome

Answer 30

``` LQTS1 = KCNQ1 LQTS2= KCNQ2 LQTS3 = SCN5A ``` Autosomal dominant 70-80% positive gene test

Question 31

When do events occur in LQTS?

Answer 31

LQTS1 - events in exercise LQTS2- load noise LQTS3- events during sleep or rest BIGGEST RISK WHEN QT >500

Question 32

Management of LQTS

Answer 32

Beta blockers for all | AICD for high risk and previous events

Question 33

Brugada Syndrome

Answer 33

Diagnosis on ECG - downsloping ST segment Peak prevalence of SCD in 4th decade Elicit with flecainide challenge

Question 34

Other Syndromes

Answer 34

Catecholaminergic polymorphic VT Short QT syndrome Idiopathic VT

Question 35

1st degree heart block

Answer 35

PR >0.2 secs Benign Unless bifascicular block --> advanced block

Question 36

2nd degree heart block

Answer 36

Type 1: - Increasing PR interval --> dropped QRS - No indication for PPM Type 2: - No variation in PR interval - non conducted P waves - PPM if very bradycardic

Question 37

3rd degree heart block

Answer 37

PPM unless asymptomatic and rate >40

Question 38

Pacing in heart failure

Answer 38

LVEF <50% = bi-ventricluar pacing | Results in less death and heart failure hospitalisations

Question 39

How do you distinguish between constrictive pericarditis and restrictive cardiomyopathy?

Answer 39

Tissue Doppler imaging Constrictive PC = fast and large E wave Restrictive CM = slow and small E wave