Study

Question 1

What are cardiac arrhythmias

Answer 1

Accelerated, slowed or irregular heart rates caused by abnormalities in the electrical impulses of the myocardium

Question 2

What are supra ventricular arrhythmias

Answer 2

Arrhythmias which originate in the sinoatrial node, atrial myocardium or atrioventricular node
Regular QRS complex

Question 3

What are ventricular arrhythmias

Answer 3

Ones which originate below the atrioventricular node

Wide QRS complex

Question 4

What are supraventricular premature beats

Answer 4

Atrial contractions triggered by ectopic foci rather than the sinoatrial node
They arise within the atria (atrial premature beats) or through retrograde conduction in the atrioventricular node (juntional premature beats)

Question 5

What causes supraventricular beats

Answer 5

Idiopathic
Potential triggers:
-smoking
-alcohol 
-coffee
Cardiovascular disease or electrolyte imbalances (eg hypokalaemia)

Question 6

What are the atrial premature beats

Answer 6

Extrasystole that originates in the atrial myocardium and occurs prior to the expected QRS complex

Question 7

What are the ECG findings of atrial premature beats

Answer 7

P wave abnormalities or absent P waves
Altered PR interval in the premature beats, compared to the normal beats
QRS complec may be normal, aberrant (widened) or absent
No full compensatory pause

Question 8

What are the ECG findings of junctional premature beats

Answer 8

Retrograde P wave
Narrow QRS complex
No compensatory pause

Question 9

What are juntional premature beats

Answer 9

Premature beat that occurs prior to the expected QRS complex and the originates between the atria and the ventricles

Question 10

How do supraventricalar beats present in patients

Answer 10

Usually asymptomatic

Palpitations

Question 11

How do supraventricalar beats get diagnosed

Answer 11

ECG: identify supraventricular premature beats

Echocardiography: to rule out structural heart disease and evaluate cardiac structure and function if SPBs are identified on ECG

Further work up if structual abnormalities are present

Question 12

How are supraventricular premature beats treated

Answer 12

Not required in asymtomatic individuals without underlying structural heart defects

Underlying conditions (eg electrolyte imbalances) should be treated

Symptomatic patients:

• advise to reduce potential triggers like caffeine, alcohol, stress and smoking
• beta-blockers or catheter ablation in patients with persistent symptoms

Question 13

What is atrial fibrillation

Answer 13

A common type of supraventricular tachyarrhythmia characterised by uncoordinated atrial activation that results in an irregular ventricular response.
Always evaluate for mitral valve involvement

Question 14

What is the epidemiology of AF

Answer 14

Most common sustained arrhythmia
Incidence increases with age; lifetime risk of those >40 y/o is 1 in 4
>95% of individuals with AF are 60 years or older
~1% of US population

Question 15

What are the major risk factors for AF

Answer 15

PARASITE

Pulmonary disease
Anemia
Rheumatic hear disease
Atrial myxoma (a benign tumor found in the heart)
Sepsis
Ischaemia
Thyroid disease
Ethanol

Question 16

What are the effects of AF

Answer 16

The atria contract rapidly but ineffectively and in an uncoordinated fashion leading to stasis of blood within the atria and so increasing risk of thromboembolism and stroke

Irregualr activation of the ventricles by conduction through the AV node leads to tachycardia

Question 17

What are the clinical features of AF

Answer 17

• Most affected individuals are asymptomatic
• Less commonly, affected individuals develop symptoms of Arrhythmias such as palpitations, dizziness, syncope, fatigue or SOB
• May show signs of underlying disease causing AF
• Tachycardia with irregularly irregular pulse
• Apex-pulse deficit (difference between the rate of the apex heart beat and that of the peripheral pulse)
• Complications of long standing AF

Question 18

What are the potential complications of longstanding AF

Answer 18

Acute left heart failure leading to pulmonary oedema
Thromboembolic events 
- Stroke/ TIA
- Renal infarct
- Splenic infarct
- Intestinal ischaemia
- Acute limb ischaemia
Life threatening ventricular tachycardia

Question 19

How is AF diagnosed

Answer 19

ECG:

• Irregularly irregular rhythm
• Variable rate - tachycardia is common; atrial rate > ventricular rate
• No p waves or PR interval
• Typically narrow QRS complex (<0.12 secs)

FBC: to test for anaemia and infection
U and Es to detect imbalances; kidney function (U and creat)
Serum glucose to assess hyperglycaemia
TFTs for hyperthyroidism 
LFTs for liver disease

Consider to evaluate complications and underlying aetiology:

• Troponin
• BNP
• Ddimer
• Serum toxicology

Echocardiogram
Chest Xray

Question 20

What is atrial flutter

Answer 20

A supraventricular tachycardia that is usually caused by a macroreentrant rhythm within the atria

Question 21

What are the ECG findings of atrial flutter

Answer 21

Rate: ~75-150 bpm
Atrial rate ≥ ventricular rate
Regular, narrow QRS complexes
Rhythm:
- regularly irregular is occurs with a variable AV block occurring in a fixed pattern
- irregularly irregular with a variable block occurring in a nonfixed pattern
Sawtooth appearance of P waves: identical flutter waves (F waves) that occur in sequence at a rate of ~300/min

Question 22

How is AF treated

Answer 22

Unstable patient: immediate electical cardioversion
Stable patient: rate and rhythm control

Rate control:
Target HR:
- <110 bpm in asymptomatic or normal LV systolic function
- <80 bpm in symptomatic with a lenient rate
Consider especially in elderly
Contraindicated in AF due to preexcitation syndromes
Options:
First line:
-Beta blockers (not in COPD
-Nondihydropyridine calcium channel blockers (not in decompensated heart failure)
Second line:
-Digoxin (first line in decomp HF where BB contraindicated)
Third line:
-amiodarone (reserved for those where all other options have failed)
Surgical options:
AV noda; ablation and implantation of a permanent ventricular pacemaker
- indicated in recurrent AF or those who don’t tolerate pharmacological options

Rhythm control:
Indicated in:
- failure of rate control strategy
- new onset AF
- acute illness that precipitated AF
- tachy induced cardiomyopathy, pregnancy, patient preference, younger patients
Options are:
-electrical cardio version
-pharmacological cardioversion
-interventional cardioversion
Contraindications:
-Long standing persistent AF
-Reversible causes (eg digoxin toxicity or electrolyte imbalances)
-High risk of thromboembolic events
Initiate anticoagulation before cardioversion to reduce risk of stroke

Question 23

What is the CHA2DS2-VASc score

Answer 23

A validated scoring system for asessing risk of stroke in nonvalvular AF
1- Congestive heart failure
1- Hypertension
2- Age ≥ 75 years
1- Diabetes
2- Prior Stroke, TIA or thromboembolism
1- Vascular disease
1- Age 65-74
1- Female sex

Risk of stroke:
0 points (male) or 0–1 point (female): low risk
1 point (male) or 2 points (female): intermediate risk
≥ 2 points (male) or ≥ 3 points (female): high risk

Question 24

What is the HAS-BLED score

Answer 24

Scoring system used to assess the risk of bleeding in patients starting anticoagulation
High risk is not a reason to withhold anticoagulants, may just need greater monitoring

1- Hypertension
1 (each, max 2)- Abnormal renal or liver function
1- Stroke
1- Bleeding history or predisposition
1- Labile INR
1- Elderly (>65 years)
1 (each, max 2)- Drugs which predispose to bleeding, or alcohol use

Interpretation
0 points: low risk
1–2 points: moderate risk
≥ 3: high risk

Question 25

What is atrial fibrillation with rapid ventricular response

Answer 25

AF with HR >100-110 bpm