Arrhythmias 3
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Transcript 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
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
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
Anterior MI
Inflammatory (rheumatic fever, myocarditis)
Autoimmune (SLE, systemic sclerosis)
Hyperkalaemia
Infiltration (sarcoid, haemochromatosis, amyloid)
Treatment
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
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
Ventricular Tachycardia
Torsades de Pointes
Ventricular Fibrillation
Narrow Complex Tachyarrhythmias
(Supraventricular Tachycardias)
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
As for AF
Hyperkalaemia
Digoxin toxicity.
Treatment
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)
Causes
Cardio (HTN, valvular disease, CAD, myositis)
Pulmonary (PE, pneumonia, COPD, lung Ca)
Metabolic (hyperthyroidism)
Infection
Drugs (alcohol, illicit drugs)
AF
Investigations
Bedside – ECG/24 hour tape
Bloods – FBC, U&Es, LFTs, TFTs, coag screen
Imaging – CXR, echo
Management (Rate vs Rhythm)
Rate –
Beta blockers
Digoxin
Rhythm
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
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