What is the next step in managing an elderly female patient with a complex medical history, including rheumatoid arthritis, recurrent urinary tract infections (UTIs), failure to thrive, cellulitis, neuropathy, restless leg syndrome, history of cerebrovascular accident (CVA)/transient ischemic attack (TIA), and general weakness, who has experienced two episodes of bradycardia, with lab results showing anemia, impaired renal function, and dehydration?

Immediate Management of Bradycardia with Anemia and Renal Dysfunction in an Elderly Patient

This patient requires immediate evaluation for BRASH syndrome (Bradycardia, Renal failure, AV-nodal blockade, Shock, and Hyperkalemia), with urgent assessment of potassium levels, medication review for AV-nodal blocking agents, and consideration of temporary pacing if symptomatic bradycardia persists. 1

Critical Initial Assessment

Obtain immediate 12-lead ECG and continuous cardiac monitoring to document the bradycardia, assess for AV block, and identify the specific rhythm disturbance (sinus bradycardia vs. AV nodal block vs. infranodal conduction disease). 2

Essential Laboratory Workup

• Check serum potassium immediately - hyperkalemia is a critical component of BRASH syndrome and can synergize with renal dysfunction to cause profound bradycardia resistant to atropine. 1
• Repeat comprehensive metabolic panel focusing on BUN/creatinine ratio (currently 48/1.07 = 45:1, suggesting prerenal azotemia or dehydration). 2
• Obtain troponin levels to exclude acute myocardial infarction as a cause of transient AV block, which would require different management. 2
• Check thyroid function (TSH) as hypothyroidism can cause bradycardia and is common in elderly females. 2

Medication Review - Critical Priority

Immediately review and hold all AV-nodal blocking agents (beta-blockers, calcium channel blockers, digoxin, clonidine) and renin-angiotensin system inhibitors that may be contributing to hyperkalemia and renal dysfunction. 1 The combination of these medications with acute kidney injury creates the perfect storm for BRASH syndrome, where bradycardia becomes resistant to standard interventions like atropine. 1

Hemodynamic Assessment

Determine if the patient is hemodynamically stable or unstable:

If Unstable (Hypotension, Altered Mental Status, Chest Pain, Heart Failure)

• Initiate transcutaneous pacing immediately if available, though recognize this is a temporizing measure only. 2
• Administer atropine 0.5-1 mg IV (may repeat up to 3 mg total), but recognize that atropine may be ineffective in BRASH syndrome or infranodal block. 3, 4
• Consider dopamine infusion (2-10 mcg/kg/min) for symptomatic bradycardia with hypotension, as used successfully in documented BRASH cases. 1
• Prepare for transvenous temporary pacing if pharmacologic measures fail and the patient remains symptomatic. 2

If Stable

• Continue continuous cardiac monitoring for at least 24-48 hours to observe for recurrent episodes and assess for transient vs. persistent conduction abnormalities. 2
• Observe for at least 72 hours before considering permanent pacing, as conduction abnormalities may be reversible once metabolic derangements and medication effects resolve. 2

Address Underlying Metabolic Derangements

Hyperkalemia Management (If Present)

If potassium >5.5 mEq/L with ECG changes or >6.0 mEq/L:

• Calcium gluconate 1-2 grams IV for cardiac membrane stabilization. 1
• Insulin 10 units IV with dextrose 50 grams (D50W). 1
• Consider urgent hemodialysis for resistant hyperkalemia, especially given the BUN of 48 and creatinine 1.07 suggesting acute-on-chronic kidney disease. 1

Anemia Management

The hemoglobin of 9.7 g/dL requires investigation but not immediate transfusion unless the patient is hemodynamically unstable or has active ischemia. 2 Routine transfusion in hemodynamically stable patients with hemoglobin >8 g/dL provides no benefit and may cause harm. 2

• Evaluate for source of anemia: Check iron studies, B12, folate, reticulocyte count, and stool guaiac. 2
• Consider anemia of chronic disease given the multiple comorbidities (chronic kidney disease, recurrent infections, inflammatory conditions). 2

Volume Status and Renal Function

The BUN:creatinine ratio of 45:1 with albumin 3.3 suggests prerenal azotemia:

• Administer cautious IV fluid resuscitation with isotonic crystalloid (250-500 mL boluses) while monitoring for fluid overload, given the history of heart failure risk factors. 2
• Avoid nephrotoxic agents including NSAIDs and contrast dye unless absolutely necessary. 2
• Adjust all renally-cleared medications based on estimated creatinine clearance. 2

Determine Need for Permanent Pacing

Permanent pacemaker implantation is NOT indicated at this time because: 2

1. The bradycardia may be entirely reversible once medications are adjusted and metabolic abnormalities corrected. 2
2. Transient bradycardia in the setting of acute illness does not constitute an indication for permanent pacing. 2
3. A minimum observation period of 72 hours is recommended to allow for recovery of AV conduction. 2

Permanent pacing WOULD be indicated if: 2

• Symptomatic bradycardia persists after correction of reversible causes
• Third-degree AV block is documented (especially if infranodal)
• Second-degree Mobitz II AV block is present
• Symptomatic sinus node dysfunction persists despite medication adjustment

Evaluate for Cardiac Ischemia

Given the history of CVA/TIA, consider cardiac ischemia as a potential cause:

• Inferior MI can cause transient AV block due to increased vagal tone or decreased blood supply to the AV node. 2
• If troponin is elevated, this represents acute MI with conduction disturbance requiring urgent cardiology consultation and possible cardiac catheterization. 2
• Temporary pacing may be needed, but permanent pacing should be deferred until adequate observation period has passed. 2

Additional Diagnostic Considerations

Screen for atrial fibrillation with Holter monitoring once the acute bradycardia resolves, given the patient's age >65 years, diabetes, hypertension, and history of CVA/TIA. 5 Paroxysmal atrial fibrillation may be completely absent on resting ECG but still cause thromboembolic events. 5

If atrial fibrillation is detected:

• Calculate CHA₂DS₂-VASc score (will be ≥2 with age, diabetes, hypertension, and prior stroke). 5
• Initiate oral anticoagulation with a NOAC (apixaban, rivaroxaban, dabigatran, or edoxaban) to prevent recurrent thromboembolic events. 5

Common Pitfalls to Avoid

• Do not implant a permanent pacemaker within 72 hours of presentation, as this may result in unnecessary device implantation when the conduction abnormality is reversible. 2
• Do not give atropine in the setting of suspected infranodal block (wide QRS escape rhythm), as it may worsen the situation by increasing AV nodal conduction while the His-Purkinje system remains blocked. 2
• Do not transfuse blood routinely for hemoglobin >8 g/dL in stable patients, as this provides no benefit. 2
• Do not restart AV-nodal blocking agents until the bradycardia has completely resolved and the patient is hemodynamically stable for at least 48-72 hours. 1
• Do not overlook hyperkalemia as a reversible cause of bradycardia, especially in patients with renal dysfunction on ACE inhibitors or ARBs. 1