Arrythmias Flashcards
What is an innappropriate bradyarrhythmia?
<60 bpm
What is an innappropriate tachyarrhythmia?
> 100 bpm
What is 3rd degree heart block?
Blocked connection between atria and ventricles
What effect does 3rd degree heart block have on the cardiac rhythm
HR is slow, degree of slowing depends on location of block
What are some of the causes of 3rd degree heart block?
Idiopathic bundle branch fibrosis, atherosclerotic coronary heart disease(ischaemia leading to damage), dilated cardiomyopathy
What are the symptoms of 3rd degree heart block
Temporary syncope as heart stops, breathlessness, fatigue, chest pain (esp with effort)
What would an ECG of a patient with 3rd degree heart block show?
Atrioventricular dissociation
Atria and ventricles beat independently of each other, QRS complex becomes dissociated from P wave
What is AF
Chaotic atrial rhythm with rapid, irregularly irregular ventricular rhythm
What are the risk factors for AF?
Atrial dilatation, HF, hypertension, excessive alcohol intake, old age, thyrotoxicosis
What are the symptoms of AF?
Palpitations, breatlessness, dizziness, syncope
What tests would be done to see if a patient has AF
ECG - would show atrioventricular dissociation
TFT
U&E’s
What would an ECG of a patient with AF look like
Lack of P waves + irregularly irregular QRS complex
F wave present (fibirilatory wave) present instead)
What is the anti-arrhythmic drug classification system called?
Vaugham Williams and Singh
What is the Vaughan Williams and Singh drug classification system + examples
Class 1: Na channel blockers - suppress conduction - flecainide
Class 2: Beta blockers - reduce excitability - bisoprolol
Class 3: Drugs which prolong the refractory period - amiodarone
Class 4: Ca channel blockers - inhibit AVN conduction - verapamil
What are Vaughan Williams and Singh class 1 drugs + example
Na channel blockers to supress conduction
Flacainide
What are Vaughan Williams and Singh class 2 drugs + example
Beta blockers - reduce excitability
Bisoprolol
What are Vaughan Williams and Singh class 3 drugs + example
Drugs which prolong the refractory period
Amiodarone
What are Vaughan Williams and Singh class 4 drugs + example
Ca channel blockers to inhibit AVN conduction
Verapamil
What is ventricular tachycardia
A run of rapid (120-200) successive ventricular beats caused by an ecopic site in one of the ventricles
What causes ventricular tachycardia
Cardiac scarring after MI or dilated cardiomyopathy
What will an ECG look like in a patient with ventricular tachycardia?
Either monomorphic VT or polymorphic VT (torsades de pointes)
AV dissociation
What shape is polymorphic ventricular tachycardia on an ECG
Torsades de pointes
Where is an implanted defibrillator placed?
Connected to electrodes in right ventricle and superior vena cava
