- Maintain patent airway; assist breathing as needed
- Administer oxygen
- Attach cardiac monitor; monitor pulse, blood pressure, perfusion
- Establish IV/IO access
Initial Assessment & Support
- Obtain a 12-lead ECG if available
- Consider causes and correctables (fever, dehydration, pain, hypoxia)
Evaluate Rhythm & Cardiopulmonary Status
Is there cardiopulmonary compromise?
If compromise is present, be prepared for synchronized cardioversion without delay.
Check QRS duration
- Narrow (< 0.09 s) → often SVT
- Wide (≥ 0.09 s) → possible ventricular tachycardia (VT)
Narrow-QRS Tachycardia (likely SVT)
Features suggesting SVT
- P waves absent/abnormal, RR interval not variable
- Infant rate usually ≥ 220/min; child rate ≥ 180/min
- History of abrupt rate change
Management
- Consider vagal maneuvers
- If IV/IO access present, give adenosine
- If rhythm irregular, WPW suspected, or adenosine fails → synchronized cardioversion
Wide-QRS Tachycardia (possible VT)
Features suggesting VT
- Wide QRS (≥ 0.09 s) with AV dissociation/capture beats
- History of structural heart disease, myocarditis, or drug toxicity
Management
- If compromise present → immediate synchronized cardioversion
- If rhythm regular and monomorphic, adenosine may be considered with expert input
- Otherwise, expert consultation is recommended
Key Doses (Typical PALS)
| Therapy | Dose / Notes | Referral |
|---|---|---|
| Synchronized cardioversion | Begin at 0.5–1 J/kg; if not effective, increase to 2 J/kg. Sedate if needed, but don’t delay. | PALS Dosing |
| Adenosine | First dose 0.1 mg/kg rapid IV/IO bolus (max 6 mg); second dose 0.2 mg/kg rapid bolus (max 12 mg). Use with continuous monitoring. | PALS Dosing |
Confirm doses with your local PALS card or institutional protocol.
Cited Keywords & Referral Links
Each keyword links to the main site or a related post on gyathshammha.com.
Bottom line
Stabilize ABCs, get a rhythm strip, decide narrow vs wide, and act: vagals/adenosine for likely SVT; early synchronized cardioversion if unstable or when adenosine is contraindicated/ineffective; consult experts for wide-QRS rhythms and suspected VT.
This guide is for education and does not replace clinical judgment or institutional protocols.