Arrhythmia Flashcards
Cardiac causes [6]
Ischemic heart disease
Structural changes
Cardiomyopathy
Pericarditis
Myocarditis
Aberrant conduction pathways (WPW syndrome)
Non cardiac causes [5]
Electrolyte imbalance Metabolic - hypoxia/acidosis/thyroid Caffeine, Smoking, Alcohol Pneumonia, phaeochromocytoma Drugs
Drugs that cause arrhythmia [5]
Levodopa Digoxin Beta 2 agonists (asthma drugs) Tricyclic antidepressants Doxorubicin
Presentation [7]
Palpitations Dyspnoea Chest pain Fatigue syncope/presyncope Pulmonary oedema Can be asymptomatic
Initial mx of arrhythmias [6]
ABCDE
Oxygen
Gain IV access
12 lead ECG
Correct metabolic abnormalities
Classify patient as stable or unstable
Stable vs unstable arrhythmia patient [6]
Signs of shock: Hypotension, Tachycardia Pallor, Peripheral cyanosis Cold, clammy hands and feet, Sweating Confusion Syncope Myocardial ischemia, Heart failure, Pulmonary oedema (fine crackles), Raised JVP
What is a sinus arrhythmia? [3]
Management?
Normal conduction at faster frequency
HR increases inspiration
Decreases expiration
No Rx needed
Causes of sinus arrhythmia [7]
Infection, fever
dehydration, hypovolaemia
pain / exercise
drugs, salbutamol
adrenaline
PE
hypothyroid
MI
What type of tachycardias are there [2]
Supraventricular - narrow complex
Ventricular - broad complex
Sinus
What is sinus arrest? [2]
Management [2]
SA node fails to generate an impulse
No pulse
Mx:
CPR pathway
Adrenaline
What is a narrow complex tachycardia and why? [4]
> 100BPM
QRS <120
Short P wave
Ventricles depolarised via normal pathway so QRS normal
Types of narrow complex tachycardias [5]
Sinus tachycardia
Atrial tachycardia - due to abnormal signal in atria other than SA node
Atrial flutter
AV re-entry tachycardia
(WPW)
AV nodal re-entrant tachycardia = most common cause of paroxysmal (re-entrant point through AV node)
What is WPW [2]
ECG [2]
AV re-entrant tachycardia - another pathway through atrial and ventricle not AV node
As the accessory pathway does not slow conduction AF can degenerate rapidly to VF
ECG:
- short PR interval
- wide QRS complexes with a slurred upstroke - ‘delta wave’
What causes irregular narrow complex [3]
Atrial fibrillation
Ectopic
Atrial flutter with variable block
What is atrial tachycardia [2]
What can cause an atrial tachycardia?
Group of atrial cells act as pacemaker
P wave different (more pointy) but everything else same
Cause: digoxin toxicity
How does WPW present [8]
SVT - associated AF / flutter or tachy Palpitations SOB Dizzy Chest pain Sweating Anxious Syncope
What is associated with WPW [4]
How do you treat WPW [2]
HOCM
Mitral valve prolapse
Ebstein
Thyrotoxicosis
Radiofrequency Ablation = definite
Amiadarone / fliecanide if AF (rhythm control)
What is type A WPW
Type B WPW
Type A: L pathway so RAD
Dominant R in V1
Type B: R pathway so LAD
No dominant R wave
What are adverse signs of supra ventricular tachy which you should assess for [5]
Chest pain (MI) Syncope Shock Heart failure Can be peri-arrest and go into VF or systole = emergency
In a patient with SVT…
What do you do if rate is regular [3]
If rate is irregular what is the most likely problem?
Continuous ECG
Valsalva manœuvre
Carotid sinus massage
If irregular, most likely the diagnosis is AF
What do you do when someone presents in SVT [6]
ABCDE O2 if low sats IV access Bloods Monitor ECG (narrrow/broad QRS) and BP Identify and treat reversible cause e.g. electrolyte
What should you do if someone has adverse signs? [8]
Treat as VT rater than SVT Put out crash call DC shock up to 3 times under sedation Seek expert help Correct electrolyte imbalance IV Amiadarone after shock, 300mg over 10-20 mins Repeat shock IV amiadarone infusion over 24 hours
What do you do for sinus tachy
Not an arrhythmia so no cardio version
Rx = treat cause
If no cause can be found = BB
What do you do if suspect AVRT / AVNRT?
2nd line: [5]
Contraindications of 2nd line [5] (what would you give instead to these patients)
What to do if 2nd line management fails [1]
Block AV node by performing Valsalva or carotid sinus massage (will stop tachy)
IV adenosine (chemical cardioversion) 6mg then 12mg then 12mg if no response
- Need continuous ECG monitoring
- Given as rapid bolus into large proximal vein
- Can cause Brady which is scary but transient - warn patient
- Do ECG during infusion
- CI in asthma / COPD / HF / heart block / severe hypo so give verapamil
- May need to direct cardiovert if doesn’t work