Tachyarrhythmias Flashcards
Case 1
- 27 y.o. man with asthma
- 3 days runny nose, sore throat, headache, feverish
- Clenil and PRN salbutamol inhalers
- HR 112 reg/strong, BP 125/55, CRT<2s
- sats 98% (A), RR 18, chest clear
- temp 36.0 / abdo SNT / GCS 15
- throat little red, no exudate, no cervical lymphadenopathy
-
1a) This is his ECG. What is your dx?
sinus tachycardia
2b) what are the causes of sinus tachycardia?
- physiological: exercise, pregnancy
- infection
- dehydration
- pain
- hyperthyroidsm
- PE
- anxiety
- drugs: cocaine, speed, salbutamol
Case 2
- 35 y.o. man, smokes, no reg meds
- at work on building site
- 20 minute sudden onset palpitation with central chest tightness, light headness
- looks clammy
- HR 200 ?reg, BP 120/86, CRT=2
- chest clear, RR 26, sats 98% air
- temp 36.2 / abdo SNT / GCS 15
-
2a) This is his ECG. What is the dx?
AV node re-entrant tachycardia (AVNRT) = “paroxysmal SVT”
2b) In whom does AVNRT occur in?
- young adults
- female > men
- triggers: caffeine, drugs, fatigue
- rate >180bpm
2c) How is AVNRT managed?
- vasovagal manoeuvres
-
adenosine IV bolus 6mg / 12mg / 12mg → monitor ECG
- C/I in asthma! → profound bronchospasm → give CCB
- DC cardioversion if adverse features
2d) What are the adverse features?
- shock
- syncope
- myocardial ischaemia
- heart failure
what does supraventricular tachycardia mean?
- supraventricular = originates above ventricles
- tachycardia, HR>100bpm
- narrow complex <120ms / 3 small squares
what are the types of SVT?
-
Atrial
- sinus tachycardia
- AF
- atrial flutter +/- variable block
-
AV Node
- AVNRT - ‘paroxysmal SVT’
- Wolff-Parkinson-White
Case 3
- 78 y.o. man
- PMH: IHD, HTN, T2DM, CKD3, ex-smoker
- meds: aspirin, simvastatin, ramipril, metformin, GTN, NKDA
- 3 day productive cough + fever
- HR 130 irreg irreg, BP 135/65, CRT<2, no leg oedema, JVP normal
- left basal creps, no wheeze, sats 98%, RR 19
- temp 38.2 / abdo SNT / GCS 15 / BM 11.9
- PU this AM, slightly darker than usual
- bloods: urea 10.1, creatinine 148 (baseline for pt 90-100), CRP 78, WCC 13.4, lactact 2.1
- CXR: left basal consolidation, cardiomegaly
- urine dip: negative
-
3a) This is his ECG. What is the dx?
atrial fibrillation
- irregularly irregular
- no P waves
- narrow QRS (<120ms / 3 small boxes)
- normal target rate for AF ~90bpm
- ‘rapid ventricular rate’ >100bpm
3b) Name 2 scoring systems that could be used in this pt to assess how unwell he is.
- CURB-65
- SIRS
- qSOFA
3c) Why might he have AF?
- pneumonia
- dehydration / AKI
- structural heart disease: IHD + HTN
3d) What do you consider in the mx strategies for AF?
Consider:
- what is the BP?
- are there adverse features?
- is there a precipitating cause?
Mx:
- rate or rhythm control?
- add on anticoagulation?
3e) What is the aim for AF mx?
<110bpm
asymptomatic
3d) What are medications that can be used in rate control for AF?
- bisoprolol
- rate-limiting CCB e.g. verapamil
- digoxin
3e) What are medications that can be used for rhythm control in AF?
- amiodarone
- flecainide
3f) What are medications that can be used for anticoagulation in AF?
- warfarin
- DOAC e.g. edoxaban
3g) How would you manage this pt?
- treat underlying cause
- sepsis 6
- withhold nephrotoxics
- check electrolytes
- repeat ECG once underlying illness better
- if persistent AF: rate / rhythm / anticoagulate
what is atrial fibrillation?
- SA node overwhelmed by disorganised electrical activity in roots of pulmonary veins
- pulmonary veins fibrosed due to atrial dilatation
what causes atrial dilatation?
- HTN
- valvular disease
- heart failure
- cardiomyopathy
- MI
- cocaine
how do you decide whether to mx with rate / rhythm control for AF?
how do you decide when to anticoagulate the pt with AF?
Case 4
- 62 y.o. man in CCU
- anterior NSTEMI 2 days ago, DAPT
- PMH: HTN, smoker
- meds: DAPT, amlodipine, ramipril
- nurse asks you to see him as he looks clammy and feels dizzy with chest pain
- looks grey
- HR 160, thready, BP 86/40, CRT=3, JVP norma
- chest clear, RR 26, sats 94% air
- temp 37.4 / abdo SNT / GCS 14
-
4a) This is his ECG. what is the dx?
ventricular tachycardia
broad complex tachy
4b) How would you manage this pt?
adverse feature present: shock ⇒ cardioversion
periarrest call (needs sedation)
amiodarone
what is ventricular tachycardia?
- originates from ventricles
- broad complex >120ms / 3 small squares (usually bigger)
- regular
- >3 successive beats
- usually >120bpm
- rx: amiodarone if stable / synchonised DC cardioversion if adverse features
what are the causes of VT?
- MI → ventricular scarring
- coronary heart disease
- congenital heart disease
- electrolyte disturbance
- cardiomyopathy e.g. HOCM
- infection e.g. myocarditis
Case 5
- 72 y.o. presents with lower urinary tract sx and agitation
- recently rx for a UTI by her GP with ciprofloxacin
- you suspect she is suffering from hyperactive delirium
- FY1 prescribes a sedative with accordance with GGC handbook. shortly after, she collapses.
PMH: recurrent UTI, depression
meds: amitriptyline
-
5a) This is her ECG. What is the dx?
Torsades de pointes
5c) What is the likely cause of this pt’s deterioration?
combination of QT prolonging drugs
e.g. macrolides, quinolones, amitriptyline, antipsychotic, ondansetron
5d) What is the rx for Torsades de pointes?
- IV magnesium
- synchronised DC cardioversion (if adverse features)
- stop all precipitants
what does this ECG show and how would you manage this?
ventricular fibrillation
no CO, heart not functioning
arrest call, start CPR!
narrow complex
atrial
broad complex
ventricular
irregularly irregular
AF
HR >180
probably AVNRT
HR consistently 75 / 100 / 150
probably flutter (saw tooth ECG)
what does adenosine treat
AVNRT and uncovers underlying rhythms
what to do if adverse features present
synchronised DC cardioversion
