Tachycardia algorithm Flashcards
What is the primary treatment of unstable tachycardia?
Immediate cardioversion is recommended.
- Drugs are generally not used
Definition and reason for symptoms of unstable unstable tachycardia
Heart rate is too fast > 100bpm
Causes symptoms or unstable condition:
- Heart beating too fast: output is reduced which can cause, pulmonary edema, coronary ischemia, hypotension with reduced perfussion of vital organs
- Heart beating ineffectively so the coordination reduces cardiac output.
Signs and symptoms of unstable tachycardia
Hypotension Acutely AMS Signs of shock Ischemic chest discomfort AHF
Causes of sinus tachycardia
Response to extrinsic factors: - fever - anemia - hypotension/shock - blood loss - exercise Sinus tach will not respond to cardioversion, and may increase.
Action for atrial flutter with hr > 150
Symptoms are often present
- cardioversion often required
Algorithm of tachycardia with a pulse step 1
Assess clinical condition:
- HR typically > or equal to 150 bpm
Algorithm of tachycardia with a pulse step 2
Identify and treat underlying cause:
- Maintain airway, assist with breathing
- O2 if hypoxemic
- Cardiac monitor to identify rhythm, BP and O2 sat
Algorithm of tachycardia with a pulse step 3
Are there signs of unstable tachycardia
Yes: Step 4: Consider cardioversion
No: Step 5: Is the QRS wide
Algorithm of tachycardia with a pulse step 5
- is the QRS wide in the stable tachycardia? Yes
If yes:
- IV access
- ECG if available
- Consider adenosine only if regular and monomorphic (first dose 6 mg rapid IV push; follow with NS flush, 2nd dose 12 mg if required)
- Consider antiarrhythmic infusion
- Consider expert consultation
Algorithm of tachycardia with a pulse step 5
- is the QRS wide in the stable tachycardia? No
If no:
- IV access
- ECG if available
- Vagal maneuvers
- Adenosine (if regular)
- B-blocker or CCB
- Consider expert consultation
Unstable tachycardia with pulse, regular, wide-complex VT (monophasic): action?
- Treat with synchronized cardioversion an initial shock of 100 J
- If no response to first shock, increase dose in stepwise fashion
What is the basic assumption and action if the patient has unstable wide-complex tachycardia
Assume it is VT until proven otherwise
Amount of energy is determined by morphologic characteristics:
If polymorphic QRS (polymorphic VT) such as torsades de points: treatment?
Treat as VF:
- high-energy unsynchronized shocks
If any doubt if monomorphic or polymorphic VT: treatments?
Do not delay treatment:
- Provide high-energy, unsynchronized shocks
Algorithm of tachycardia with a pulse step 4:
Action if tachyarrhthmia is causing symptoms?
Synchronized cardioversion
- Consider sedation
- If regular narrow complex, consider adenosine
(assuming monomorphic VT here I think?)
In which conditions should synchronized shocks be given?
- Unstable SVT
- Unstable atrial flutter
- Unstable atrial fibrillation
- Unstable regular monomorphic tachycardia with pulses
When to use unsynchronized shocks?
- For a patient who is pulseless
- Clinical deterioration, severe shock or polymorphic VT
- When you feel delay in giving a shock will result in cardiac arrest
- When unsure whether polymorphic or monomorphic VT
Energy dose for atrial fibrillation cardioversion?
Monophasic: initial 200 J synchronized shock
Biphasic: initial 120-200 J synchronized shock
- Escalate the second and subsequent shock dose as needed.
Energy dose for atrial flutter and SVT cardioversion?
Generally require less than atrial fibrillation
- 50-100 J biphasic or monophasic
Energy dose for monomorphic VT (regular form and rate) cardioversion
Initial dose 100J mono or biphasic
- Subsequent shocks increase stepwise
What is the treatment for regular narrow-complex tachycardia (except sinus tachycardia)?
Vagal maneuvers and adenosine
Features of stable tachycardia
HR greater than 100 bpm
No significant symptoms cause by the increase
Underlying cardiac abnormality that generates the rhythm
Most wide-complex tachycardias originate where?
Usually ventricular in origin
What is the therapy for narrow QRS with regular rhythm?
Attempt vagal maneuvers
Give adenosine
Adenosine contraindications
May cause bronchospasm and generally not given in patients with asthma or COPD
