Approach to Tachycardia Flashcards
(35 cards)
1st step in approaching patient with tachycardia?
ABCDE to determine if they are stable or unstable.
What are some signs of an unstable patient with tachycardia?
1) Shock: hypotension (<90 mmHg), pallor, sweating, cold, clammy extremeties, confusion or impaired conciousness.
2) Syncope
3) Myocardial ischaemia
4) HF
If any adverse signs are present in a patient with tachycardia, what is the next step?
Synchronised DC shocks.
Up to 3 shocks can be given –> then seek expert help.
How many synchronised DC shocks can be given in unstable patients with tachycardia?
Up to 3 - then seek expert help
What history may be present in patients with tachycardia?
- palpitations
- exercise intolerance
- lightheadedness
- syncope
Key investigation in tachycardia?
ECG –> assess regular or irregular, broad or narrow complex.
If patient with tachycardia is stable, what is next step?
Get an ECG –> determine if the QRS if narrow or broad.
What is a narrow QRS?
<120ms
What is a broad QRS?
> 120ms
What does a narrow complex tachycardia indicate?
That the pacing originates above the ventricles –> suggests you are dealing with SVT (if regular).
Stepwise mx of regular narrow complex tachycardia? (4)
1) Vagal manoeuvres
2) IV adenosine (monitor ECG continuously):
- 6mg rapid IV bolus
- 12mg
- 18mg
3) Verapamil or beta blocker
4) Synchronised DC shock up to 3 atttempts (sedation or anaesthesia if conscious)
Mx of sinus tachycardia?
Treat cause e.g. fever, anxiety, pain, exercise, hyperthyroidism, pregnancy, anaemia.
What are some vagal manoeuvres used in narrow complex regular tachycardia? (3)
1) valsalva manoeuvre
2) applying a cold stimulus to the face e.g. application of a bag filled with ice and cold water over the face for 15-30 secs
3) carotid sinus massage
What do Valsalva manoeuvres commonly used include?
1) forceful exhalation against a closed airway for approximately 15-20 seconds
2) blowing into an occluded straw
3) adopting a head-down position for approximately 15-20 seconds
When is a carotid sinus massage contraindicated?
If any history of carotid artery disease
If adenosine is contra-indicated or fails in the management of SVT, what is the 2nd line medication?
Verapamil –> given IV over a two-minute period
What is an irregular narrow-complex tachycardia most likely to be?
Atrial fibrillation (or less commonly atrial flutter with a variable atrio-ventricular block)
Mx of AF with duration of <48 hours?
Can be offered rhythm control or rate control.
Note –> rhythm control is recommended in most patients with a new onset of AF presenting at this time.
What are the options for rhythm control in AF <48 hours?
1) DC Cardioversion,
2) Chemical cardioversion:
- flecainide
- propafenone
- amiodarone
When can flecainide & propafenone not be used in rhythm control of AF?
What can be used instead?
If evidence of structural heart disease or HF.
Use amidarone or digoxin instead.
Mx of AF >48 hours?
Do not treat with cardioversion until they have been anti-coagulated for at least 3 weeks, to reduce the risk of dislodging an atrial thrombus.
If a patient with AF >48 hours BUT is unstable and requires urgent cardioversion, what do you do?
Give LMWH or UH first
Heparin treatment as well as oral anti-coagulation should be commenced after cardioversion (whether successful or not)
What is aim of rate control of AF?
To decrease the heart rate at rest and during exertion
Symptoms are normally associated with high heart rates.
What medications can be used for rate control of AF?
1) Beta blockers
2) Non-dihydropyridine calcium channel blockers e.g. verapamil and diltiazem
3) Digoxin (but not recommended outside of sedentary patients with non-paroxysmal AF)
