Pacemaker ECG with the Littmann sign.

Area of Science:

• Cardiology
• Internal Medicine
• Critical Care Medicine

Background:

• Severe hyperkalemia can present subtly on electrocardiograms (ECGs).
• BRASH syndrome (Bradycardia, Renal failure, Arrhythmia, Shock, Hyperkalemia) is a complex condition requiring prompt diagnosis.
• The Littmann sign, or heart rate double counting, is a recognized indicator of severe hyperkalemia in critically ill patients.

Observation:

• A critically ill patient presented with severe bradycardia.
• The patient's electrocardiogram (ECG) findings were initially non-specific for severe hyperkalemia.
• Hyperkalemic double counting (Littmann sign) was observed only on the ECG performed during percutaneous pacing.

Findings:

• The Littmann sign was crucial for the early recognition of severe hyperkalemia.
• The patient was diagnosed with BRASH syndrome, facilitated by the identification of hyperkalemia.
• The subtle presentation of hyperkalemia highlights the importance of specific ECG findings in critical care.

Implications:

• Early recognition of the Littmann sign can lead to timely diagnosis and management of hyperkalemia and BRASH syndrome.
• This case underscores the utility of specific ECG markers in identifying life-threatening electrolyte imbalances.
• Clinicians should be vigilant for subtle ECG signs of hyperkalemia, especially in critically ill patients with bradycardia.