What is the management approach for a patient presenting with hypotension and wide complex tachycardia?

Admission Orders for Hypotensive Wide Complex Tachycardia

This patient requires immediate synchronized cardioversion given hemodynamic instability (BP 80/50) with wide complex tachycardia, presuming ventricular tachycardia until proven otherwise. 1, 2

Immediate Interventions (Within Minutes)

Cardioversion Preparation

• Prepare for immediate synchronized cardioversion - this is Class I recommendation for unstable tachycardia with hypotension 1, 2
• Sedate if conscious and time permits (consider etomidate 0.2-0.3 mg/kg IV given hypotension) 1
• Have defibrillator at bedside with pads applied
• If defibrillator not immediately available, consider precordial thump for witnessed, monitored unstable VT (Class IIb) 1

Monitoring & Access

• Continuous cardiac monitoring with telemetry 2
• Establish two large-bore IV lines (18-gauge or larger) 2
• Continuous blood pressure monitoring (consider arterial line if remains unstable) 2
• Pulse oximetry with supplemental oxygen to maintain SpO2 >94% 2
• Obtain 12-lead ECG immediately (but do not delay cardioversion for this) 1, 2

Medication Orders

If Cardioversion Delayed or Patient Stabilizes

• Amiodarone 150 mg IV over 10 minutes - preferred for wide complex tachycardia with hypotension/heart failure 1, 3
  • Can repeat to maximum 2.2 g/24 hours 1
  • Monitor for further hypotension (most common adverse effect, occurs in 16% of patients) 3
  • Slow infusion rate if hypotension worsens 3

Vasopressor Support (Given BP 80/50)

• Norepinephrine infusion: Start 8-12 mcg/min (2-3 mL/min of standard 4 mcg/mL dilution), titrate to maintain SBP >90 mmHg 4
  • Mix 4 mg in 1000 mL D5W for 4 mcg/mL concentration 4
  • Administer through central line if possible; if peripheral, use large vein with close monitoring 4
  • Target MAP 65 mmHg or SBP 80-100 mmHg 4

Alternative Antiarrhythmics (If Amiodarone Unavailable)

• Procainamide: Class IIa recommendation for stable wide complex tachycardia 1
• Sotalol 1.5 mg/kg IV over 5 minutes: Class IIb recommendation 1
  • Avoid if QT prolonged 1

Medications to AVOID

• Do NOT give adenosine - contraindicated in unstable or irregular/polymorphic wide complex tachycardia (may cause degeneration to VF) 1, 2
• Do NOT give verapamil or diltiazem - contraindicated for wide complex tachycardia unless definitively proven SVT (can cause hemodynamic collapse) 1, 2
• Do NOT give beta-blockers - contraindicated in hypotensive state 1

Diagnostic Workup

Immediate Labs

• Stat electrolytes (K+, Mg2+, Ca2+) - correct abnormalities immediately 1, 5
• Troponin, BNP
• Complete blood count
• Renal function (creatinine, BUN)
• Toxicology screen if history unclear 6
• Medication levels if on antiarrhythmics (digoxin, flecainide) 6

Imaging

• Portable chest X-ray (assess for heart failure, structural abnormalities)
• Echocardiogram once stabilized (assess ventricular function, structural disease) 1

Monitoring Parameters

• Continuous telemetry monitoring
• Blood pressure every 5 minutes until stable, then every 15 minutes
• Hourly urine output (target >0.5 mL/kg/hr)
• Serial 12-lead ECGs (baseline, post-intervention, then every 4-6 hours)
• Monitor QTc interval if amiodarone administered 3

Critical Pitfalls to Avoid

• Never delay cardioversion in unstable patients while waiting for 12-lead ECG 2
• Treat all wide complex tachycardia as VT unless proven otherwise - giving calcium channel blockers or beta-blockers for presumed SVT when rhythm is actually VT causes hemodynamic collapse 1, 2, 5
• Do not normalize heart rate if tachycardia is compensatory for low cardiac output 2
• Correct volume depletion before/concurrent with vasopressor therapy - occult hypovolemia is common cause of refractory hypotension 4
• Avoid multiple AV nodal blocking agents - can cause profound bradycardia 2

Disposition & Consultation

• ICU/CCU admission - all patients with unstable wide complex tachycardia require intensive monitoring 1
• Immediate cardiology/electrophysiology consultation - required for all wide complex tachycardia of unknown etiology 1, 2
• Consider electrophysiology study and possible ablation once stabilized 1

Special Considerations

• If rhythm regular and monomorphic after stabilization, adenosine 6 mg rapid IV push may be used diagnostically (Class IIb), but only if patient stable 1
• Heart rates <150 bpm rarely cause symptoms unless ventricular function severely impaired 2
• If patient has known structural heart disease or prior MI, VT is overwhelmingly likely diagnosis 5, 7