Arrhythmias Flashcards

1
Q

Where does a Supraventricular Arrhythmia originate?

A

above the ventricle, i.e., SAN, atrial muscle, AV node or HIS origin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Where does a Ventricular Arrhythmia originate?

A

origin is in ventriclar muscle (common)

or fascicles of the conducting system (uncommon)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Name some types of SVT?

A
Supraventricular tachycardia
Atrial Fibrillation
Atrial Flutter
Ectopic atrial tachycardia
Bradycardia
Sinus bradycardia
Sinus pauses
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Name some types of VT?

A

Ventricular ectopics or Premature Ventricular Complexes (PVC)
Ventricular Tachycardia
Ventricular Fibrillation
Asystole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Name some AV node arrhythmias?

A

AVN re-entry tachycardia
AV reciprocating or AV re-entrant tachycardia
AV block - 1st, 2nd or 3rd

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Outline the clinical causes of Arrhythmias?

A
Abnormal anatomy
Autonomic nervous system (ANS)
hyperthyroidism
Metabolic
Inflammation
Drugs
Genetic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What abnormal anatomy may cause arrhythmias?

A

left ventricular hypertrophy
accessory pathways
congenital heart defect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What Autonomic nervous system changes may cause arrhythmias?

A

Sympathetic stimulation: stress, exercise, hyperthyroidism

Increased vagal tone causing bradycardia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What metabolic changes may cause arrhythmias?

A

Hypoxia: chronic pulmonary disease, pulmonary embolus
Ischaemic myocardium: acute MI, angina
Electrolyte imbalances: K+, Ca 2+, Mg2+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What inflammation may cause arrhythmias?

A

viral myocarditis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What drug effects may cause arrhythmias?

A

direct electrophysiologic effects or via ANS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What genetic defects may cause arrythmias?

A

mutations of genes encoding cardiac ion channels e.g. the congenital long QT syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are Ectopic Beats?

A

Beats or rhythms that originate in places other than the SA node

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What may cause ectopic beats?

A

Altered automaticity e.g. ischaemia, catecholamines

Triggered activity, e.g. digoxin, long QT syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is re-entry?

A

requires more than one conduction pathway, with different speed of conduction (depolarization) and recovery of excitability (refractoriness)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What may cause re-entry?

A

accessory pathway tachycardia (Wolf Parkinson White syndrome)
scar from previous myocardial infarction or congenital heart disease
Conditions that depress conduction velocity or shorten refractory period promote functional block, e.g. ischaemia, drugs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe the mechanism of tachycardia?

A

The ectopic focus may cause single beats or a sustained run of beats, that if faster than sinus rhythm, take over the intrinsic rhythm.
Re-entry: triggered by an ectopic beat, resulting in a self perpetuating circuit.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the symptoms of Arrhythmias?

A
Palpitations, “pounding heart”
Shortness of breath
Dizziness
Loss of consciousness; “Syncope”
Faintness: “presyncope”
Sudden cardiac death
Angina, heart failure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is Wolf Parkinson White Syndrome?

A

pre-excitation on an ECG (wide QRS and short PR)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the investigations of Arrhythmias and why?

A

12 lead ECG (in tachycardia, during SR)
CXR
Echocardiogram – assess structural heart disease
Stress ECG
- Look for myocardial ischaemia, exercise related arrhythmias
24 hour ECG Holter monitoring – assess paroxysmal arrhythmias
Event recorder: (capture the arrhythmia)
Electrophysiological (EP) study
- Induce clinical arrhythmia to study mechanism and map arrhythmia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What can cause sinus bradycardia?

A

Physiological i.e., athlete
Drugs (B-Blocker)
Ischaemia: common in inferior STEMIs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How do you treat sinus bradycardia?

A

Atropine (if acute, e.g. acute MI)

If haemodynamic compromise: hypotension, CHF, angina, collapse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What can cause sinus tachycardia?

A

Physiological - Anxiety, fever, hypotension, anaemia

Inappropriate - drugs, etc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the treatment of sinus tachycardia?

A

Treat underlying cause

B-adrenergic blockers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the signs and treatment for atrial ectopic beats?

A

Asymptomatic or palpitations
B-adrenergic blockers may help
Avoid stimulants (caffeine, cigarettes)

26
Q

What is Regular Supraventricular Tachycardia due to?

A

AV nodal re-entrant tachycardia (AVNRT)
AV reciprocating tachycardia / AV re-entrant tachycaria (via an accessory pathway) (AVRT)
Ectopic atrial tachycardia (EAT)

27
Q

What is the Acute management of SVT?

SVT: Supraventricular Tachycardia

A
  • Increase vagal tone: valsalva, carotid massage
  • Slow conduction in the AVN
  • IV Adenosine
  • IVVerapamil
28
Q

What is the chronic management of SVT?

A
  • Avoid stimulants
  • Electrophysiologic study and Radiofrequency ablation (first line in young, symptomatic patients)
  • Beta blockers
  • Antiarrhythmic drugs
29
Q

What is Radiofrequency Catheter Ablation?

A

Selective cautery of cardiac tissue to prevent tachycardia, targeting either an automatic focus orpart of a re-entry circuit

30
Q

What are the causes of heart block/AV conducting disease?

A
Ageing process
Acute myocardial infarction
Myocarditis
Infiltrative disease
Amyloid
Drugs
-	B-adrenergic blockers
-	Calcium channel blockers
Calcific aortic valve disease
Post-aortic valve surgery
Genetic: Lenegre’s disease, myotonic dystrophy
31
Q

What are the ECG characteristics of 1st Degree AV block?

A

Conduction following each P wave but takes longer.

P-R interval longer than normal (> 0.2 sec)

32
Q

What causes 2nd Degree AV block?

A

Intermittent block at the AVN (dropped beats)

33
Q

Describe type 1 2nd Degree AV block?

A

Mobitz 1: -progressive lengthening of the PR interval, eventually resulting in a dropped beat.
Usually vagal in origin

34
Q

Describe type 2 2nd Degree AV block?

A

Mobitz 2:
Pathological, may progress to complete heart block (3rd degree HB)
Some AP fails to get through the AV node
Usually 2:1, or 3:1, but may be variable
Permanent pacemaker indicated

35
Q

Describe type 3 AV block?

A

Complete block

No action potentials from the SA node/atria get through the A-V node

36
Q

Describe the two types of Pacemakers?

A

Single chamber: paces the right atria or right ventricle only
Dual chamber: paces the RA and RV

37
Q

What causes Ventricular Ectopics?

A
  • Structural causes: LVH, heart failure, myocarditis
  • Metabolic: Ischaemic heart disease, electrolytes
  • Beta-blockers, Ablation of focus
38
Q

What are the causes of Ventricular Tachycardia?

A
Significant heart disease
-	Coronary artery disease
-	A previous myocardial infarction
OR Rare causes:
- Cardiomyopathy
- Inherited/ Familial arrhythmia syndromes
- Long QT, Brugada syndrome
39
Q

What is the Acute treatment of VT?

A

Direct current cardioversion (DCCV) if unstable.

If stable: consider pharmacologic cardioversion with AAD

40
Q

What is the chronic treatment of VT?

A

Correct ischemia if possible (revascularisation)
Optimise CHF therapies.
Implantable cardiovertor defbrillators (ICD) if life threatening.
VT catheter ablation.

41
Q

What are the ECG characteristics of VT?

A

o The QRS complexes are rapid, wide, and distorted.
o The T waves are large with deflections opposite the QRS complexes.
o The ventricular rhythm is usually regular.
o P waves are usually not visible.
o The PR interval is not measurable.
o A-V dissociation may be present.
o V-A conduction may or may not be present.

42
Q

Describe Ventricular Fibrillation

A

Chaotic ventricular electrical activity which causes the heart to lose the ability to function as a pump

43
Q

What are the 2 treatments of Ventricular Fibrillation?

A

Defibrillation

Cardiopulmonary resuscitation

44
Q

What does a wide QRS tachycardia with history of CAD/HF indicate?

A

Ventricular Tachycardia

45
Q

What is the treatments in the ventricles AND atrium and ventricle by ICDs? (Implantable cardioverter defibrillator)

A

VENTRICLE:
VT prevention
antitachycardia pacing (ATP)
low-energy cardioversion
defibrillation for ventricular tachyarrhythmias (VT/VF).
ATRIUM AND VENTRICLE
brady sensing and pacing for bradyarrhythmias.

46
Q

What is Atrial Fibrillation?

A

the disorganized electrical activity of the atria resulting in an irregular heartbeat

47
Q

What is the mechanism of AF?

A

Initiated by rapid electrical activity arising from arrhythmogenic foci located in the muscular sleeves of pulmonary veins
The arrhythmia is maintained by multiple re-entrant wavelets.
Reduced refractoriness and conduction slowing facilitate re-entry

48
Q

What are the three types of AF?

A

Paroxysmal
Persistent
Permanent

49
Q

Describe Paroxysmal AF?

A

Paroxysmal and lasting less than 48 hours

Often recurrent

50
Q

Describe Persistant AF?

A

An episode of AF lasting greater than 48 hours, which can still be cardioverted to normal sinus rhythm
Unlikely to spontaneously revert to normal sinus rhythm

51
Q

Describe Permanent AF?

A

Inability of pharmacologic or non-pharmacologic methods to restore normal sinus rhythm

52
Q

How can AF be stopped?

A

Pharmacologic cardioversion with anti-arrhythmic drugs (30% effective)
Electrical Cardioversion (90% effective)
Spontaneous reversion to sinus rhythm

53
Q

What are the symptoms of AF?

A
Palpitations
Pre-syncope (dizziness)
Syncope
Chest pain
Dyspnea
Sweatiness
Fatigue
54
Q

What does AF look like on an ECG?

A
Atrial Rate:> 300 bpm
Rhythm: Irregularly irregular
Ventricular Rate: Variable
Absence of P waves
Presence of ‘f’ waves
55
Q

What is an F wave in an ECG?

A

irregular undulations of the base line in an electrocardiogram

56
Q

What is the Management of AF?

A

Rhythm control to Maintain SR
Rate control - accept AF but control ventricular rate
Anti-coagulation for both approaches if high risk for thromboembolism

57
Q

What is the pharmacological treatment of AF?

A
Rate control during AF- to slow down AVN conduction
-	Digoxin
-	Betablockers
-	Verapamil, diltiazem
Rhythm Control during AF- 
Restoration of NSR 
-	Pharmacologic cardioversion (anti-arrhythmic drugs e.g. amiodarone)
-	Direct Current Cardioversion (DCCV) 
Maintenance of NSR
-	Anti-arrhythmic drugs
-	Catheter ablation of atrial focus/ pulmonary veins 
-	Surgery (Maze procedure)
58
Q

What is Direct Current Cardioversion?

A

terminate the arrhythmia by the delivery of a dose of electrical current to the heart at a specific moment in the cardiac cycle

59
Q

Name drugs from Class 1 - 4 of Anti-arrhythmic drugs?

A
Class 1: reducing Na channel current
-	Lignocaine, quinidine, flecainide, propafenone
Class II: B-Adrenergic antagonists
-	Propranalol
Class III: action potential prolongation
-	Amiodarone, sotalol
-	DRONEDARONE
Class IV - Ca channel antagonists
-	Verapamil
60
Q

Describe Atrial Flutter

A

Rapid and regular form of re-entrant atrial tachycardia.

It is usually paroxysmal, and it is sustained by a macro-reentry circuit located in the right atrial myocardium

61
Q

What do patients with chronic atrial flutter have?

A

underlying heart disease?

62
Q

What is the treatment for atrial flutter?

A
RF ablation (80-90% long term success)
Pharmacologic therapy
-	Slow the ventricular rate
-	Restore sinus rhythm
-	Maintain sinus rhythm once converted
Cardioversion
Warfarin for prevention of thromboembolism