Arrhythmias - Pathophysiology, presentation and investigation Flashcards
What are the different parts of the ECG?
P wave P-R interval QRS complex S-T segment T wave
What are the possible presentations of arrhythmias?
Asymptomatic Palpitation Dyspnoea Chest pain Fatigue Embolism
What investigations should be done?
ECG - 12 lead, 24 hours recording
Full blood count
Thyroid function test
Echocardiogram
What are the main ways to treat arrhythmias?
Rate or rhythm control
Anticoagulation
What medication is used to control rate?
Digoxin
Beta blockers
Ca- antagonist plus warfarin
Aspirin
What is used to control rhythm?
Class Ic/III antiarrhythmic drugs
DC cardioversion
What are the electrical approaches to arrhythmia treatment?
Pace and ablation of AV node
Substrate modification - pulmonary vein postal ablation or maze procedure
What is ablation?
When certain areas of tissue are destroyed so that the electrical signal doesn’t propagate
What is a maze procedure?
When ablation is used to create a maze so that electrical signals follow a more predictable route
What is necessary for patients who have had AV node ablation?
A pacemaker
What is DC cardioversion?
Direct current used to shock a person so that the heart rhythm is restored
What is supraventrivcular tachycardia?
AV-nodal re-entrant tachycardia - abnormally fast heart rhythm arising from improper electrical activity in the upper part of the heart.
What are the signs and symptoms of supraventricular tachycardia?
Palpitations
Dyspnoea
Dizziness
What is a possible treatment for supraventricular tachycardia?
Radio frequency ablation
What is atrial flutter?
An abnormal heart rhythm that starts in the atrial chambers of the heart.
What does atrial flutter usually develop into?
Atrial fibrillation
How is atrial flutter treated?
Control ventricular rate Anticoagulants Antiarrhythmic drugs RFA Cardiovertion
What are the symptoms of ventricular tachycardia?
Palpitations Dyspnoea Dizziness Syncope Chest pain
What causes ventricular tachycardia?
Structural heart disease usually
What can ventricular tachycardia develop into?
Ventricular fibrillation
Cardiac arrest
How is ventricular tachycardia treated?
Cardiac arrest protocol DC cardioversion Treating the underlying cause Antiarrhythmic drugs Implantable cardioverter-defibrillator (ICD)
What is Torsades de Pointes?
A polymorphic ventricular tachycardia that exhibits distinct characteristics on the ECG
What can Torsades de Pointes lead to?
Sudden death
What can cause Torsades de Pointes?
Long QT syndrome
Atrial fibrillation
Complete heart block
What are the indication for ICD therapy?
Cardiac arrest due to VF/VT
Sustained VT causing syncope or significant compromise
Sustained VT with poor LV function
What are the indications for a temporary pacemaker?
Symptomatic bradycardia (particularly syncope)
What is a temporary pacemaker used for?
Prophylactic when a patient is at high risk of developing severe bradycardia such as 2nd or 3rd degree AV block or post anterior MI
What are the indications for a permanent pacemaker?
Symptomatic 2nd or 3rd degree AV block
Mobitz type 2 2nd or 3rd degree Av block
AV block associated with neuromuscular disease
After AV node ablation
Alternating RBBB/LBBB
Syncope when bifascicular/trifascicular block
Symptomatic sinus node disease
Carotid sinus hypersensitivity
Malignant vasovagal syncope
What is alternating RBBB/LBBB?
Alternating right bundle branch block and left bundle branch block
What is Bifascicular block?
A conduction abnormality in the heart where two of the three main fascicles of the His/Purkinje system are blocked.
What is trifascicular block?
Conducting disease in all three fascicles
