Clinical Presentation Arrhythmias Flashcards
(35 cards)
What is sinus rhythm?
- Normal heart rhythm
- Each p wave followed by QRS
Why is there slow AVN conduction?
- Safety feature - conduction of very rapid rhythm direct to ventricles prevented
- Accessory pathways can bypass AVN
What are the symptoms of an arrhythmia?
- None
- Palpitations
- Breathlessness (dyspnoea)
- Chest pain
- Dizziness/lightheadedness
- T-LOC/syncope
- Sudden death
What can palpitations be exacerbated by?
Stress, alcohol, caffeine
What causes breathlessness?
- Due to low CO
- Tachyarrhythmias = low SV
- Bradyarrhythmias = low HR
What causes dizziness/light-headedness?
Fall in CO may = drop in BP = lower cerebral perfusion
What arrhythmias can cause sudden cardiac death?
- Ventricular tachyarrhythmias
- Bradyarrhythmias
- Acute pump failure
What causes anginal chest pain?
- When myocardial demand for O2 exceeds supply
- Demand may increase due to increased HR
- Supply may decrease due to decreased CO
What are the causes of sudden cardiac death?
2/3 = structurally abnormal heart - CAD, cardiomyopathy 1/3 = structurally normal heart - primary arrhythmia
How do you investigate intermittent arrhythmias?
- Week long cardiac event recorders
- Implantable loop recorders - reserved for T-LOC, not palpitations
What are the types of ectopic beats?
- Ventricular = broad QRS complex
- Atrial = narrow QRS complex
Often followed by compensatory pause
How are ectopic beats managed?
Lifestyle
- smoking
- alcohol
- caffeine
- chinese food - monosodium glutamate
Avoid culprit drugs
What is AF?
Irregularly irregular rhythm
No p waves
What are the categories of AF?
- Paroxysmal episodes < 48 hours
- Persistent episodes > 48 hours and < 1 week
- Permanent episodes permanent
What are cerebral thromboembolic events?
Stroke
TIA’s
How is AF treated?
- Rate vs rhythm
- Assessment of risk of stroke - CHADVASC
- Assessment of risk for anti-coagulation - HASBLED
- Should not use aspirin
How is AF rate controlled?
- Drugs target AVN to slow conduction to ventricles
- Useful for persistent/permanent AF
- B blocker, digoxin, Ca channel blockers
- Keep you in AF but slow it down
- Extreme = ablate + pace
How is AF rhythm controlled?
- Atrial stabilising drugs
- VW class IC (flecainide, propafenone)
- Class III (amiodarone, dronedarone)
- DC cardioversion
- Radiofrequency ablation
How is stroke prevented in AF?
- AF = thrombus formation in LA
- NOT aspirin
- Warfarin vs DOACs
What is the LT management of AF?
- Manageable rather than curable
- Episodes become more frequent + permanent
What is an accessory pathway?
- Enables conduction to bypass AVN
- ECG = short PR + delta wave
What is first degree heart block?
- Conduction from atria > ventricles pathologically slowed
- Due to slow conduction within AVN
- Long PR interval
- Usually no symptoms
- Often due to AVN blocking drugs
What is second degree heart block?
- Conduction from atria > ventricles intermittent
- ECG: non-conducted p waves (not followed by QRS)
- No palpitations
- Breathlessness, T-LOC + chest pain due to low CO
- Symptoms intermittent or none
What is third degree heart block?
- Conduction from atria > ventricles fails
- Heart beats escape rhythm due to severals sites of intrinsic pacemaker activity
- No palpitations
- Breathlessness, T-LOC + chest pain due to low CO
- Complete AV dissociation = dissociated p waves
