Download Arrhythmias 3

Arrhythmias
YASMINE DARWAZEH
FY1 – GENERAL SURGERY
Objectives
 Define bradyarrhythmia and tachyarrythmia
 Know the most common brady- & tachyarrythmias
 Recognise them on an ECG.
 Know the main signs and symptoms, aetiology and
treatments of each.
What can you see?
Types of bradyarrhythmia
Sinus Bradycardia
 HR < 60bpm
 Causes
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Physiological (normal in athletic people)
Iatrogenic (Beta blockers, Ca channel blockers, digoxin,
anticholinergics)
Hypothyroidism
Metabolic e.g. hyperkalemia
Hypoxia
Hypothermia
Acute MI/ischemia
 Treatment
Remove cause (ie drugs)
 Treat cause (ie hypothyroidism)

What can you see?
1st degree AV node block
 PR interval >0.2secs (more than 5 small squares)
 Delayed conduction through/near the AVN
 Usually asymptomatic
 Narrow QRS complex indicates block within AVN
 Wide QRS complex indicates His-Purkinje block.
 Causes
MI
 Myocarditis/endocarditis
 SLE
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 Treatment
 Usually benign
 Can progress to other forms of AV block
 If symptomatic, consider pacemaker
What can you see?
Mobitz type 1 (Wenkebach)
 PR interval progressively lengthens until a P wave is not
followed by a QRS complex.
 Continues as a cycle.
 Due to a conduction defect within the AVN
 Causes:
• Inferior MI
• Drugs
• Myocarditis
 Treatment
• None required (unless reversible cause)
What can you see?
Mobitz type 2
 Intermittent non-conducting P waves.
 May occur in regular pattern e.g. every 3rd p wave is
not followed by a QRS complex (3:1 block)
 Causes
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Anterior MI
Inflammatory (rheumatic fever, myocarditis)
Autoimmune (SLE, systemic sclerosis)
Hyperkalaemia
Infiltration (sarcoid, haemochromatosis, amyloid)
 Treatment
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Internal pacing eventually as likely to progress to 3rd degree
heart block
What can you see?
Complete AV block
 Complete dissociation between atrial & ventricular
depolarisations
 All impulses from atria blocked by the AVN
 Very symptomatic & very syncopal.
 Causes
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Inferior MI
Drugs (ca channel blockers, beta blockers, digoxin)
Progression of Mobitz 1 & II
Congenital (if mother has SLE)
Lev's disease: idiopathic fibrosis & calcification of conducting system
 Treatment

Internal pacing
Adult Bradycardia Algorithm
What can you see?
Sinus tachycardia
 HR > 100bpm
 Causes:
 Intra-cardiac causes
 Ishcaemic
heart disease
 Valvular heart disease
 Heart failure
 Cardiomyopathy
 Congenital heart disease
 Treatment
 Treat the cause.
Extra-cardiac causes
•Drugs
•Alcohol
•Stimulants e.g. caffeine
•Stress
•Hyperthyroidism
•Infection/Sepsis
Broad and Narrow Complex tachycardias
 Broad Complex Tachyarrhythmias
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Ventricular Tachycardia
Torsades de Pointes
Ventricular Fibrillation
 Narrow Complex Tachyarrhythmias
(Supraventricular Tachycardias)
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Sinus Tachycardia
Atrial Tachycardia
Reentrant Tachycardias (AVNRT and AVRT)
Atrial Fibrillation
Atrial Flutter
What can you see?
Atrial Flutter
SVT, regular
Saw-tooth flutter waves.
Flutter waves rate = 300 bpm
Ventricular rate = 150 bpm or 100 bpm, due to AVN
block ratio of 2:1 or 3:1
 Ectopic atrial beat causes a re-entrant circuit within the
atria.
 Causes
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As for AF
Hyperkalaemia
Digoxin toxicity.
 Treatment
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As for AF (discussed later)
Can be differentiated from Fast AF with vagal manouvres/adenosine.
What can you see?
Ventricular tachycardia
 Broad complex tachycardia
 Causes
• Electrolyte derangement (hypokalaemia, hypomagnesaemia,
hypocalcaemia)
• Myocardial ischaemia/infarct
• Cardiomyopathy
• Congenital (HOCM, long QT)
 Treatment
• Amiodarone
• ICDs
What can you see?
Atrial Fibrillation
 Atria chaotically fibrillate.
 Fibrillation rate between 350 & 600bpm.
 Variable impulse conduction through the AVN
 Irregularly irregular rhythm
 Most common arrhythmia.
 10% of population >80 years old.
 Significant morbidity due to thromboembolic disease
 Unmanaged = 5% yearly stroke risk.
Atrial Fibrillation
 Types
Paroxysmal (acute onset, spontaneous termination within 1
week)
 Persistent (>7 days, can be cardioverted)
 Permanent (> 1 year not terminated by cardioversion)
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 Causes
Cardio (HTN, valvular disease, CAD, myositis)
 Pulmonary (PE, pneumonia, COPD, lung Ca)
 Metabolic (hyperthyroidism)
 Infection
 Drugs (alcohol, illicit drugs)
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AF
 Investigations
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Bedside – ECG/24 hour tape
Bloods – FBC, U&Es, LFTs, TFTs, coag screen
Imaging – CXR, echo
 Management (Rate vs Rhythm)
 Rate –
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Beta blockers
Digoxin
 Rhythm
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Cardioversion
Sotalol
Amiodarone (HF)
AF - CHA2DS2-VASc score
 Thromboprophylaxis
C – cardiac failure (1)
 H – HTN (1)
 A - >75 (2, 1 if 65-74)
 D – diabetes (1)
 S- stroke/TIA (2)
 Va – vascular disease
 Sc – female (1)
0 = Low Risk
1 = Moderate risk
2 or more = high risk
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Summary
 Define bradyarrhythmia and tachyarrythmia
 Know the most common brady- & tachyarrythmias
 Recognise them on an ECG.
 Know the main signs and symptoms, aetiology and
treatments of each.
Any Questions