Arrhythmia Flashcards
Symptoms?
Palpitations SOB Dizzy Presyncope, syncope Sudden cardiac death angina, heart failure
Investigations?
ECG 12 ld CXR Stress ECG 24hr ECG holter Event recorder EP study
When would a 24hr Holter ECG be used?
- assess paroxysmal arrhythmia
- link symptoms to heart rhythm
When would a excersise ECG be used?
- assess for ischaemia
- assess for excerise induced arrhythmia
What is an EP study?
Electrophysiological study
Trigger clinical arrhythmia and study mech/pathway
Opportunity to treat via radiofrequency ablation if extra pathway
T/F
Bradycardia is always pathological
F
found in athletes with low muscle tone
path - drug induced or ischaemia
Treatment for bradycardia?
Acute: Atropine Haemodynamic compromise (prevent blood flow): pacing
Treatment for tachycardia?
Treat underlying cause e.g. anxiety,fever, hypotension, drugs
Beta blockers for -ve chrono
T/F
Generally, atrial ectopic beats get no treatment
T
Lead to early QRS but usually followed by pause as rhythm reasserted
Beta blockers and avoiding stimulants may help
T/F
atrial ectopic beats can be asymptomatic
T
may also present with palpitations
T/F
Sinus arrhythmia is always pathological
F
phases of variation in HR with respiration in CHILDREN & ADOLESCENTS
Causes supraventricular tachycardia?
- frequently ectopic (from either atria)
- AV re entry
- AV re entry due to accessory pathway
AVNRT?
AV node reentrant tachycardia
Re entry originates circuit WITHIN AV node
AVRT
AV re entry via path outside AV node - usually accessory pathway
What is the management for ACUTE supraventricular tachycardia?
Increase vagal tone - valsalva manouvere or carotid massage
Slow conduction in AVN
IV adenosine or verapamil
What is the management for CHRONIC supraventricular tachycardia?
Avoid stimulants
EP study and radiofrquency ablation (FIRST LINE IN YOUNG SYMPTOMATIC PATIENTS)
Beta blockers
antiarrhythmic drugs
How does EP study work?
ECG catheters placed in heart via femoral veins
Intracardiac ECG recorded during sinus rhythm, tachycardia & pacing manoevers to find location and mechanism of tachycardia
Ablate focus
Causes heart block?
Ageing
MI
Myocarditis
Drugs (beta blockers, Ca2+ blockers)
T/F
1st degree heart block not treated
T
rule out other pathology
long term follow up - could dveleop more advanced h block
T/F
Mobitz I is usually vagal in origin
T
T/F
Mobitz II is usually 5:1 normal beats to dropped beats
F
2:1 or 3:1
ventricular contraction only intiated every 2nd or 3rd beat
T/F
Pacemaker is indicated in Mobitz II
T
On an ECG 3rd degree AV block will present as…
Disassociation between P wave and QRS complex
On an ECG Mobitz II AV block will present as…
Alternating completion of beats - lone p wave for 2, p wave with qrs for one
On an ECG Mobitz I AV block will present as…
continual lengthening of PR until QRS goes missing
When is pacing indicated?
Mobitz II and Type 3 Heart block
What are features of transcutaneous pacing?
Painful for patient
Temporary - use until venous access gained for trans venous pacer
What are features of transvenous pacing?
- Via internal jugular vein, subclavian or femoral vein
When is dual chamber pacemaker indicated?
- dual chamber paces RA and RV
maintains AV synchrony
used for AVN disease
What are premature ventricular contractions?
- contractions with ventricular ectopic focus
- because originate ventricles spread slowly
- Broad QRS complex on ECG
Premature ventricular contractions can predispose to more serious arrhythmias if..
develop during or after MI
Causes of ventricular ectopics?
LVH
hert failure
Ischaemic heart disease
Treatment ventricular ectopics?
Beta blockers
Ablation
What is ventricular tachycardia?
ventricular ectopic beats
life threatening but may be haemodynamically stable
What is monomorphic VT?
the QRS complex have similar configuration
Indicates stable re entrant pathway - MI scar?
What is polymorphic VT?
Configuration QRS varies, HR varies
suggest multiple ectopic foci or unstable reentrant pathway - during or soon after MI
rare causes of VT?
Long QT syndrome
Brugada syndrome
What is VF?
Chaotic ventricular rhythm, incompatibility with cardiac output
deadly
What is the treatment for VF?
Defibrillation
Cardiopulmonary resuscitation
What is the treatment for acute VT?
Direct current cardioversion
If stable consider pharmacologic cardio version
Look for causes and correct (hypoxia, ischemia etc.)
What is the treatment for chronic VT?
Correct ischemia
Optimise heart failure therapies
ICD if life threatening
Vt ablation
T/F
Antiarrhythmic drugs are a good option for treating VT
F
Ineffective and associated with worse outcomes
