Bradycardia

• Determine if the patient is hemodynamically stable or unstable/symptomatic. Ask the nurse to get a full set of vital signs and a 12-lead EKG as you are on your way to the bedside. If concerned, have Zoll pads and atropine at the bedside. (/f unstable, see ACLS bradycardia)
• Determine whether this is sinus bradycardia (HR < 50) based on EKG.
• Review telemetry. Often the irregularity of atrial fibrillation will be misread as intermittent bradycardia on the monitor; and this typically does not require additional work-up or management. If the patient is truly having >3- second sinus pauses while awake, this indicates sinus node dysfunction (intrinsic or due to medications) and the patient potentially needs a pacemaker if symptomatic. In general, pauses during sleep are asymptomatic and are okay. Symptomatic pauses while awake are more significant.
• Take a history and examine the patient, pay attention to symptoms described above, vital sign abnormalities and mental status.
• Evaluate medication list and recently given medications (i.e.: B-blocker, CCB) and obtain electrolyte panel (especially K+) and TSH if not done recently.

• Assure that atropine and pacer pads are easily available (i.e. at the bedside if available per nursing protocol).
• If symptomatic or unstable bradycardia follow ACLS protocols for temporary pacing and consult cardiology for temporary pacing wire placement.
• Medications are a common cause of bradycardia. Be careful with abrupt discontinuation of certain medications such as rate control agents that may result in a rebound tachycardia. Holding one dose or decreasing the standing dose may be a good first attempt. Transcutaneous pacing is uncomfortable and a transition to temporary transvenous pacing wire should be made if continuous pacing for > 12 hours is anticipated. These patients should be transferred to the ICU and cardiology should be consulted.
• Treat the underlying conditions i.e. inferior MI, medication overdoses, hypothyroidism (see Endocrine: hypothyroidism), electrolyte abnormalities (especially K+).
• Special Situations:
  • Beta-blocker overdose (if severe a glucagon)
  • CCB overdose (1 amp of CaCl2, may require calcium drip)
• Class I indications for pacemaker placement in patients with bradycardia:
  • 3rd degree AV block with documented asystole >3sec in awake patients or escape rates <40 bpm
  • 3rd degree AV block with ventricular escape rhythm
  • Mobitz type II and degree AV block or 3rd degree AV block in patients with chronic bifasicular or trifascular block.
  • Symptomatic chronotropic incompetence
  • Bradycardia with symptoms of cerebral hypoperfusion (e.g., presyncope, syncope)

• Asymptomatic bradycardia in a young, athletic patient can be normal, but don’t ignore the call.
• It is important to identify the underlying rhythm in bradycardia as the management differs depending on the etiology.
• Medications are often the cause.
• Check electrolytes - pay close attention to the K.
• Inferior myocardial infarctions often cause bradycardia due to increased vagal tone and require pre-load for management of hypotension.

Have atropine at the bedside for patients with clinically significant bradycardia