Wide Complex Tachycardia Uncertain Origin

Section 4 - CARDIAC

4.10 WIDE COMPLEX TACHYCARDIA – UNCERTAIN ORIGIN (Heart rate >150 beats/minute)

• INITIAL MEDICAL CARE (2.01) - OXYGEN @ 100% via NRB mask or assist with BVM.

STABLE and SVT highly likely:

• Administer ADENOSINE 6 mg RAPID IVP, administered at a port closest to the IV site, followed immediately by a rapid 10-20 ml saline flush
• If NO response in 2 minutes, ADENOSINE 12 mg RAPID IVP followed immediately by a rapid 10-20 ml saline flush (Maximum dose 18 mg)

STABLE and unknown wide complex or ventricular tachycardia likely:

• LIDOCAINE 1 mg/kg IV over 3-5 minutes If no response, LIDOCAINE 0.5-0.75 mg/kg IV over 3-5 minutes (may repeat to a maximum of 3 mg/kg administered) In patients over age 70 or in those with known hepatic disease, administer LIDOCAINE boluses at 0.25 mg / kg (maximum of 1.5 mg / kg)

UNSTABLE WIDE COMPLEX TACHYCARDIA:

Definition of Unstable: Persistent Wide Complex Tachyarrhythmia causing:
Hypotension or signs of decreased tissue perfusion Significant dyspnea or significant compromise of the airway Acute mental status change Signs/symptoms of shock Acute heart failure Ischemic chest discomfort

• SYNCHRONIZED CARDIOVERSION
  • Initial recommended doses:
    • If narrow and regular complexes 50-100 Joules biphasic
    • If narrow and irregular complexes 120-200 Joules biphasic
    • If wide and regular complexes 100 Joules biphasic
    • If wide and irregular complexes – use defibrillation dose (not synchronized)
• If IV established prior to patient becoming UNSTABLE, may administer VERSED 2-5 mg IVP, IO or IN AND REPEAT 2 mg every 30 seconds to one minute if patient is conscious.
• If NO response, SYNCHRONIZED CARDIOVERSION @ 200 Joules.
• If NO response, SYNCHRONIZED CARDIOVERSION @ 360 Joules.

DEFIBRILLATION should be considered instead of synchronized cardioversion if the patient is deteriorating rapidly to avoid delays associated with synchronization.