Unstable Bradycardia Part 3

Bradycardia Intervention Mnemonic: PACE
P- pacemaker
A-atropine
C-chronotrophic drugs
E-evaluate Hs&Ts

Indications for TCP Pacing
• Standby for clinically stable bradycardia
• Therapeutic bridge until placement of a transvenous
• Hemodynamically unstable bradycardia

Transcutaneous pacing
• TCP should not be delayed while waiting for an IV and Atropine
• Set rate between 60-80/min
• Begin at lowest mA and increase
• Observe for electrical capture
• Assess for mechanical capture
• Consider analgesics and sedation for pain

Combo pad placement
• Avoids pacemakers and ICDs
• Insure the skin is dry
• Shave excess hair if needed
• Avoid medication patches
• Avoid letting patches touch
• Apex-anterior position
• Anterior-posterior position


Electrical Capture
• Electrical capture is observed when a pacer spike is immediately followed by a QRS complex
• Notice that the QRS complex is wide and there is ST elevation.

Paced Rhythm Without Electrical Capture

Paced Rhythm With Electrical Capture

Paced Rhythm With Electrical Capture
TCP stimulus does not work through the normal cardiac conduction system but by a direct electrical stimulus of the myocardium
Therefore, a “capture,” where TCP stimulus results in a myocardial contraction, will resemble a PVC
Electrical capture is characterized by a wide QRS complex, with the initial deflection and the terminal deflection always in opposite directions

Mechanical Capture
• Improved BP
• Palpable pulse
• Improved level of consciousness
• Improved respiratory status
• Cessation of chest pain
• Improvement in skin color

Medications
• Atropine
• Dopamine infusion
• Epinephrine infusion

Atropine
• Avoid with wide QRS bradycardia
• Initial IV dose 0.5-1.0mg
• Repeat every 3-5minutes
• Total dose 0.04mg/kg
• Atropine will not work on denervated hearts (heart transplants).
• Atropine may be considered, but if pt is in 2nd degree type II or 3rd degree block, it may extend the block to 3rd degree or asystole.

Chronotropic drugs
• For the treatment of adults with symptomatic and unstable bradycardia
• Recommended as an alternative to pacing

Dopamine
5-20ug/kg/min
• Low dose 1-5ug/kg/min
• Moderate dose 5-10ug/kg/min
• High dose 10-20ug/kg/min

Note:
At lower doses dopamine has a more selective effect on inotropy and heart rate; at higher doses (>10 mcg/kg per minute), it also has vasoconstrictive effects. Dopamine infusion may be used for patients with symptomatic bradycardia, particularly if associated with hypotension, in whom atropine may be inappropriate or after atropine fails

Epinephrine 2-10ug/min
• Epinephrine infusion
• Mix 1mg in 250 NS

Note
Epinephrine infusion may be used for patients with symptomatic bradycardia, particularly if associated with hypotension, for whom atropine may be inappropriate or after atropine fails

Isoproterenol 2-10ug/min
• Mix 4mg in 500cc of NS
• Increased myocardial ischemia,
• Hypotension
• Peripheral vasodilation

Evaluate:  5Hs & 5Ts
• Hypoxia
• Hypovolemia
• Hyper/hypokalemia
• Hydrogen ions (acidosis)
• Hypothermia

Evaluate:  5Hs & 5Ts
• Tension pneumothorax
• Thrombosis: coronary
• Thrombosis: pulmonary
• Thrombosis: Tables/toxins
• Tamponade, cardiac