Arrthymia's Flashcards
What is a ventricular arrthymia?
Origin is in ventricle
What are ectopic beats?
Beats or rhythms that originate in places other than the SA node
Name the supraventricular arrhthymias
Tachycardia - Atrial Fibrillation - Atrial Flutter - Ectopic atrial tachycardia Bradycardia - sinus bradycardia - sinus pauses
Name the AV node arrhthymias
AVN re-entry WPW AV block (1st, 2nd, 3rd degree)
Name the ventricular arrhthymias
Premature Ventricular Complex (PVC)
Ventricular Tachycardia
Ventricular Fibrillation
Asystole
What anatomical changes can cause arrhthymias?
LV hypertrophy
Accessory pathways
Congenital HD
What are the Utonomic causes of arrhythmias?
Sympathetic stimulation
(Nervousness, exercise, CHF, hyperthyroidism)
Increased vagal tone (bradycardia, heart block)
What is a supraventricular arrthymia?
Origin is above ventricle
Metabolic causes of arrhthymias
Hypoxia myocardium: chronic pulmonary disease, PE
Ischaemic myocardium
Electrolyte imbalances (K+, Ca2+, Mg2+)
Other causes of arrhythmias
Not anatomical, autonomic, metabolic
Inflammation
Drugs
Genetic
What are the physiological mechanism of arrhythmias?
Altered automaticity
Triggered activity
Re-entry
Symptoms of arrthymias
Palpitations Dyspnoea Dizziness Syncope Worsening of existing condition
Investigations for arrhythmias
ECG!!!!!!!! CXR Echocardiogram Stress ECG/24 hr monitoring EP study (induce arrthymia to study pathway)
How do you treat atrial ectopic beats?
Generally no treatment
B-adrenergic blockers may help
Avoid stimulants (caffeine, cigarettes)
Treatment for sinus bradycardia
Atropine (if acute) Pacing if: - haemodynamic compromise - hypotension - CHF - angina - collapse
Treatment for sinus tachycardia
Treat underlying cause
Beta blockers
Acute management of SVT
Vagal manoeuvres, carotid massage
IV adenosine
IV verapamil
Chronic management of SVT
Avoid stimulants Radiofrequency ablation Anti arrthymia drugs (class II or IV)
What is ablation?
Selective cautery of cardiac tissue to prevent tachycardia, targeting either an automatic focus or part of a re-entry circuit
What is 1st degree AV block?
Not really “block”
Just longer P-R interval (> 0.2 sec)
Husband is late but comes home every night
Treatment of first degree AV block
None
Long term follow up re commended incase it progresses
What is 2nd degree heart block (Mobitz type 1)?
Husband comes home later and later every night until one night he doesn’t come home at all (must come home at least twice)
Treatment for 2nd degree heart block (Mobitz type I)?
Atropine
What is 2nd degree heart block (Mobitz type II)?
Sometimes husband comes home but sometimes he doesn’t but when he does come home it’s always at the same time
Treatment for 2nd degree heart block (Mobitz type II)?
Atropine
Sometimes requires pacing
What is 3rd degree heart block?
Wife is no longer waiting at home. She and her husband are on different schedules and have no relationship. Each spouse has a regular individual schedule
Treatment for 3rd degree heart block
Temporary or permanent pacing
What do premature ventricular ectopics indicate?
May not have structural heart disease
Could be
- ischaemia heart disease
- hypertension with left ventricular hypertrophy
- inherited arrthymia syndromes (e,g, cardiomyopathy)
If worse on exercise need to investigate further
Treatment for premature ventricular ectopics
Beta blockers
Causes of VT
Coronary artery disease
Previous MI
Cardiomyopathy
Inherited arrthymia syndromes
Characteristics of VT on an ECG
Broad QRS complexes
Large T waves
Regular rapid rhythm
Usually no visible p waves
Acute treatment of VT
DC cardioversion if unstable
If stable consider pharmacological cardioversion (AADs)
Of unsure if Vt consider adenosine to make diagnosis
Long term treatment for VT
Correct ischaemia (revascularisation) Anti-arrthymic drugs Implantable cardiovertor defibrillators (ICD)
What is VF?
Chaotic ventricular electrical activity
Heart can’t pump
Treatment of VF
Defibrillation
CPR
What is AF?
Chaotic disorganised atrial activity
Irregular heartbeat
What are the 3 forms of AF?
Paroxysmal ( 48 hours but can still be cardioverted to NSR)
Permanent
Diseases associated with AF
Hypertension CHF Sick sinus syndrome Coronary heart disease Thyroid disease Valvular heart disease Cardiac surgery
Symptoms of AF
Palpitations Dizziness Syncope Chest pain Dyspnoea Sweatiness Fatigue
Where is the ectopic focus in AF?
Around the pulmonary veins
Treatment of AF
Anti-arrhythmic drugs
Electrical cardioversion
Examples of anti arrhthymic drugs used in AF
Digoxin
Betablockers
Verapamil, diltiazem
What does AF look like on an ECG?
Absent P waves
What are the classes of anti-arrhthymic drugs?
Class I: reduce NA channel current
(Flecainide, quinidine, lignocaine, propafenone)
Class II: Betablockers
(Propranolol)
Class III: Prolong action potential
Amiodarone, sotalol, dronedarone)
Class IV: ca channel antagonists
(Verapamil)
What is TdP and how is it recognised on an ECG?
Distinct type of VT
Long QT interval
Wide QRS
Continually changing QRS morphology
What can lead to TdP?
Hypokalemia
Drug induced prolongation of action potential
Renal impairment
What indicates the need for anticoagulation in valvular AF?
Mitral valve disease (MS & MR)
What indicates the need for anticoagulation in patients with non valvular AF?
Age > 75 Hypertension Heart failure Previous thromboembolism CAD/ DM Diabetes
What is atrial flutter?
Rapid and regular form of atrial tachycardia
What is the treatment for atrial flutter?
RF ablation
Pharmacological therapy
Cardioversion
Warfarin (prevent thromboembolism)
What rhythms are shockable?
VF
VT
What arrthymias are not shockable?
Asystole (adrenaline 1mg)
PEA (adrenaline 1mg)
