The nurse managing complete heart block must rapidly assess the clinical significance and initiate protocol-based interventions. The block may occur at three levels: (1) AV node -- produces junctional escape rhythm (40-60 bpm, narrow QRS), responds to atropine, common in inferior MI, often transient; (2) His bundle -- produces junctional or fascicular escape (35-50 bpm, may be narrow or wide QRS), variable atropine response; (3) Below His bundle (bilateral bundle branch block) -- produces ventricular escape (20-40 bpm, wide QRS), does NOT respond to atropine, unreliable escape, common in anterior MI, usually permanent. The ACLS bradycardia algorithm guides management: if unstable (hypotension, altered mental status, signs of shock, ischemic chest pain, acute HF), atropine 0.5 mg IV is first-line (max 3 mg); if no response or infranodal block, transcutaneous pacing; if transcutaneous pacing fails or is a bridge, dopamine 5-20 mcg/kg/min or epinephrine 2-10 mcg/min infusion. Transcutaneous pacing technique: place anterior-posterior pads, set rate 60-80 bpm, increase output from lowest setting until electrical capture (pacing spike followed by wide QRS and T wave) and mechanical capture (palpable pulse with each...