Tachycardia; Unstable Narrow Complex
Determine Patient Stability
Patient is considered unstable if there is hypotension, poor skin signs, shortness of breath, chest pain, evidence of CHF, or decreased mentation [or any other symptom felt to be caused by the bradycardia].
- Evaluate ABC's
- Stabilize Airway/Breathing
- Apply oxygen
- Place cardioversion/defibrillation pads
- Establish IV
- Monitors (Rhythm, Oximetry, BP)
- Obtain 12 lead EKG
- Code cart
- Obtain history and perform physical examination and consider causes:
- Differential diagnosis includes:
- Consider Causes
- Acute myocardial infarction, pulmonary embolus
- Hypovolemia/Hypoxia/Hypothermia
- Metabolic: Thyroid disease, hyper/hypokalemia, hypercalcemia, acidosis
- Hypoglycemia
- Drugs: Cocaine, Amphetamines, Decongestants, Ephedra, Ginseng
- Pneumothorax or Tamponade
- Cardiomyopathy/Valvular heart disease
- Alcohol related ("Holiday heart")
- Sepsis/Pneumonia
* Do not treat Sinus Tachycardia with this protocol; identify underlying condition and treat * - Treatment for unstable narrow complex tachycardia:
- Sedation if possible and immediate cardioversion.
- Sedation:
- If patient is conscious, provide sedation (agents such as Etomidate, Fentanyl or Midazolam are common choices)
- Synchronized cardioversion:
- Pads on patient (or paddles)
- Press sync button (make sure to have 3 lead monitor leads attached to the defibrillator/cardiovertor)
- Evaluate rhythm to determine appropriate initial Joule setting:
- Afib: 100-200J
- A-flutter/SVT: 50-100J
- Monitor for response to therapy; if needed, increase joules for subsequent shocks in stepwise fashion and make sure to press the sync button prior to each shock.
- Standard laboratory evaluation (if indicated):
- CBC, Electrolytes, TSH, Cardiac enzymes and toxicology testing
- CXR
- EKG pre and post conversion (if conversion occurs)
- Consultation and admission to hospital if indicated.
Source: Circulation 2005;112. 2005 AHA Guidelines for CPR and ECC.