Arrhythmia - Narrow Complex / Cardiac Arrest / Pacemaker Flashcards
What should all elderly / people with syncope / stroke get
Other investigations for arrhythmia
ECG
Can do continuous if think paroxysmal
FBC, U+E, LFT, glucose, Ca, TSH, Mg
Drug review
Other ECHO Exercise ECG Angiogam Drug review
What type of arrhythmia’s can you get
Sinus
Tachy
Brady
What cardiac causes arrhythmia
IHD Structural changes - dilatation due to MR Cardiomyopathy Pericarditis Myocarditis Conduction issues
What are non-cardiac causes
Electrolyte imbalane Metabolic - hypoxia / acidosis / thyroid Caffiene Smoking Alcohol Phaeochromocytoma Pneumonia Drugs - digoxin / TCA / B2 agonist
How does an arrhythmia present
Asymptomatic Palpitations Chest pain Syncope Hypotension Pulmonary oedema
What should you ask in the history of someone with palpitations
SOCRATES Other cardiac Sx Review drugs PMH FH sudden cardiac death
What is concerning with syncope
Syncope when exercise
What is a sinus arrhythmia
Normal conduction at faster frequency
HR increases inspiration
Decreases expiration
Infection / dehydration / pain / exercise / drugs / adrenaline / salbutamol / PE / hypothyroid / hypovolaemia/ MI / fever
No Rx needed
What are indications for temporary pacing
Symptomatic bradycardia - particularly if syncope
Prophylactic 2nd or 3rd degree block
What are indications for permanent pacing
2 or 3rd degree block symptomatic RBBB / LBBB Sinus node disease Carotid sinus hypersensitivity Severe HF Malignant vasovagal syncope
When is a ICD indicated
Cardiac arrest due to VT or VF not caused by a reversible cause
Often get in HCM
Sustained VT causing syncope
Sustained VT with poor LV function
What type of tachycardia’s is there
Supraventricular - narrow complex
Ventricular - broad complex
Sinus
What is sinus arrest
SA node fails to generate an impulse
No pulse
How do you Rx sinus arrest
CPR pathway
Adrenaline ASAP
Where do narrow complex arise
Atria (supraventricular)
Due to extra pathway or extra electrical loop through AV node and back into atria
What is a narrow complex tachycardia
> 100BPM
QRS <120
Short P wave
Ventricles depolarised via normal pathway so QRS normal
What causes a regular narrow complex tachycardia
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
AV re-entrant tachycardia - another pathway through atrial and ventricle not AV ode
What causes irregular narrow complex
Atrial fibrillation
Ectopic
Atrial flutter with variable block
What are the symptoms
Asymptomatic Fast HR Palpitations SOB Dizzy Chest pain
What terminates supra ventricular tachycardia
Valsalva
What do you suspect if a patient with no history presents with supraventricular tachy / AF / palpitations
Alcohol binge
What is atrial tachycardia
Group of atrial cells act as pacemaker
P wave different (more pointy) but everything else same
What can cause an atrial tachycardia
Digoxin toxicity
What is AVRT
Accessory pathway e.g. WPW allows electrical activity from atrial to ventricles
New circuit created
What is AVNRT
Circuits form in AVN
Very common
What are adverse signs of supra ventricular tachy which you should assess for
Chest pain / MI Syncope Shock - Hypo / pallor / sweating / confusion / impaired consicous Heart failure - Pulmonary oedema or raised JVP
Can be peri-arrest and go into VF or asystole = emergency
If rate is irregular what is the most likely Dx
AF
What do you do if rate is regular
Continuous ECG
Valsalva manœuvre
Carotid sinus massage
What do you do when someone presents in SVT
ABCDE O2 if low sats IV access Bloods Monitor ECG and BP 12 lead ECG to see if narrow or broad Identify and treat reversible cause e.g. electrolyte
What should you do if someone has adverse signs
Treat as VT rater than SVT Put out crash call DC shock up to 3 times under sedation SEEK EXPERT HELP Correct electrolyte 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
Block AV node by performing Valsalva or carotid sinus massage (will stop tachy)
What do you do if Valsalva / carotid sinus massage fails
What is needed
When is it CI and what do you give instead
What do you warn patient about
IV adenosine - resets back to sinus rhythm
6mg then 12mg then 12mg if no response
Need continuous ECG
Given as rapid bolus into large proximal vein
Can cause Brady which is scary but transient - warn patient as half life 10s
Do ECG during infusion
CI in asthma / COPD / HF / heart block / severe hypo so give verapamil
May need to cardiovert if doesn’t work
If sinus rhythm is restored what does this suggest
AVRT
Consider anti-arrhythmia prophylaxis if recurs
What do you suspect if sinus rhythm not achieved with adenosine and what is required
Atrial flutter
AF if irregular
SEEK expert help and rate control with BB
How do you prevent supra ventricular tachy
BB / CCB / amiadarone - block AV node
Ablation to take out accessory pathway
What is the Valsalva manoeuvre
Forced expiration against closed glottis Increases intrathoracic pressure Reduced venous return due to increased atrial pressure Reduced preload Reduced CO
What is WPW
Congenital accessory conduction pathway
Leads to AVRT
Early excitation of ventricles by bypassing AV node
What is risk of WPW
Degneration to VF as does not slow conduction as AV node is bypassed
How does WPW present
SVT - associated AF / flutter or tachy Palpitations SOB Dizzy Chest pain Sweating Anxious Syncope
What is associated with WPW
HOCM
Mitral valve prolapse
Ebstein
Thyrotoxicosis
What does ECG show
Short PR <0.12
Wide QRS with slurred upstroke and delta wave which is the accessory pathway
ST changes
What is type A
L pathway so RAD
Dominant R in V1