Palpitations and dysrhythmias Flashcards
What can cause AF?
-HF / IHD / HTN
-Dehydration (alcohol, drugs)
-Thyroid disease
-Hypokalaemia
-PE
-Sepsis
How would you manage AF?
-Treat underlying cause / illness
-Consider emergency electrical cardio version if there are signs of:
–Shock
–Syncope
–Acute HF
–Ischaemia
-Chemical cardioversion eg flecanide or amiodarone
-If >48h at risk of thromboembolism so anticoagulant and use rate control drugs:
How would you manage AF?
-Treat underlying cause / illness
-Consider emergency electrical cardio version if there are signs of:
–Shock
–Syncope
–Acute HF
–Ischaemia
-Chemical cardioversion eg flecanide or amiodarone
-If >48h at risk of thromboembolism so anticoagulant and use rate control drugs:
–Beta blocker/CCB (diltiazem, digoxin)
How does atrial flutter appear on ECG compared to AF?
Atrial flutter = saw-tooth (constant atrial depolarisation)
AF = irregularly irregular, absent P waves
What RFs are there to having SVT?
-Previous MI
-MV prolapse
-Congenital heart disease
-Previous cardiac surgery
-RHD
-Pericarditis
-Pneumonia, chronic lung disease
-Alcohol intoxication
-Digoxin toxicity
How does SVT present?
-Palpitations
-Light-headedness
-Syncope
-Tachycardia
How does SVT appear on ECGs compared to VT?
SVT:
-Tachycardia
-Short QRS
VT:
-Tachycardia
-Broad QRS (>120ms)
(Brugada criteria is used to differentiate)
How should you manage SVT?
-Usual A-E, 12-lead ECG, o2, treat reversible causes
-Assess for signs of instability eg MI, shock, syncope
-IV adenosine or DC cardioversion
-BB or ablation use as prevention
How does VT present?
Symptoms of IHD / haemodynamic compromise / HF
-Chest pain
-Palpitations
-Dyspnoea
-Dizziness
-Syncope
-Signs on examination reflect degree of haemodynamic instability eg basal crepitations, raised JVP, lethargy
What are the two main types of VT?
Monomorphic (commonly caused by MI)
Polymorphic (precipitated by prolonged QTc, eg tornadoes de pointes)
How would you manage VT?
-Correct haemodynamic instability ie O2, diuretics
-Electrical or chemical cardioversion:
–IV Amiodarone 300mg, then 900mg over 24h
–Lidocaine
–Magnesium sulphate if polymorphic
–Do not use diltiazem as can induce cardiac arrest
-Implantable defib if recurrent and poor LV function
What happens in VF?
-Ventricle muscle fibres contract randomly causing complete failure of ventricular function
-Often associated with coronary artery disease
What causes VF?
-Antiarrhythmic drug administration
-Hypoxia
-Ischaemia
-AF
-Electric shock (cardioversion or accidental)
How should you manage VF?
-A-E and immediate CPR
-Defib (shockable rhythm)
-Adrenaline and amiodarone after 3rd shock
-Correct reversible causes
What are the reversible causes of cardiac arrest?
4 Hs
-Hypoxia –> give o2
-Hypovolaemia –> correct with IV fluids
-Hypothermia
-Hyper-/hypokalaemia –> or other metabolic disorders
4 Ts
-Thromboembolism (cardiac, pulmonary) –> thrombolysis
-Tension pneumothorax –> needle aspiration
-Tamponade
-Toxins
What are the definitions of the different types of heart block?
GENERAL = atrial activity is not conducted to the ventricles
1st degree = lengthened PR interval
2nd degree
-Mobitz I = progressive prolongation of PR until dropped beat occurs
-Mobitz II = PR interval constant but dropped beats occur randomly or in a pattern
3rd degree / complete = no association between P and QRS
What can cause heart block?
-IHD
-Congenital
-Aortic valve calcification
-Cardiac surgery / trauma
-Digoxin toxicity
-Can be idiopathic
What symptoms does heart block cause?
-Syncope
-HF
-Regular bradycardia
-Fatigue, dizziness, chest pain, SOB
-Impaired exercise tolerance
-Poor perfusion
How should you manage heart block?
-Identify and treat causes
-Atropine or adrenaline may be used
-May need pacemaker if not drug or infection related
What investigations should you order for patients presenting with dysrhythmias?
-ECG, HR, BP
-Bloods - U+Es, cardiac enzymes, TFTs, ?digoxin levels, calcium, magnesium, phosphate
-CXR and echo if ?HF or ?infective cause
