Bradycardia

Definition

Bradycardia is a resting adult heart rate less than 60 bpm. It can be physiologic (in well-conditioned athletes, during sleep) or pathologic (from disease or medications).

Causes

• Athletic conditioning
• Vagal stimulation (bearing down, vomiting)
• Increased intracranial pressure (part of Cushing’s triad)
• Hypothyroidism, hypothermia
• Inferior wall MI (involves SA/AV node)
• Medications: beta-blockers, calcium channel blockers, digoxin (toxicity), opioids, amiodarone
• Heart block (2nd- or 3rd-degree)

Signs and Symptoms

Fatigue, dizziness, syncope, hypotension, chest pain, dyspnea, and altered mental status when perfusion is compromised.

Nursing Interventions

Assess for symptoms of poor perfusion. For symptomatic bradycardia per ACLS: atropine 1 mg IV push, repeat every 3 to 5 minutes to a total of 3 mg; transcutaneous pacing if unresponsive; consider epinephrine or dopamine drip. Hold offending medications and notify provider.

NCLEX Relevance

Classic scenario: hold digoxin for apical rate less than 60 bpm. Recognize bradycardia in Cushing's triad (HTN, bradycardia, irregular respirations).