Pacemaker ECG with the Littmann sign.

Severe hyperkalemia may be concealed in the electrocardiogram (ECG). We present the case of a critically ill patient with severe bradycardia and the BRASH syndrome. In critically ill patients, double counting of the heart rate is frequently a marker of severe hyperkalemia (Littmann sign). In our case, hyperkalemic double counting only appeared in the ECG performed during percutaneous pacing. The Littmann sign helped with the early recognition of hyperkalemia and the BRASH syndrome.

Double counting heart rate - Littmann sign in electrocardiogram.

This report highlights necessity of correctly and quickly identifying Littmann sign. Littmann sign is not common in clinical practice, which is easily overlooked by most physicians, leading to delays in the treatment of hyperkalemia. A 68 year old patient with hyperkalemia was found to have inconsistent heart rate displayed on electrocardiogram monitoring with cardiac auscultation and synchronous electrocardiogram in the early stages of onset. Hyperkalemia was highly suspected by the Littmann sign. After completing arterial blood gas analysis, hyperkalemia was identified and active potassium lowering treatment was immediately initiated. The Littmann syndrome disappeared, and the patient eventually recovered.

QRS double counting by ECG software in ST elevation myocardial infarction.

A 62-year-old female patient suffering from ST elevation myocardial infarction (STEMI) was transported to a cardiology facility. During transport, the monitor triggered an alarm for tachycardia despite a normal pulse. The reason was a misinterpretation of the ECG software, which double counted the QRS complex. QRS double counting has been reported in the setting of hyperkalemia only. In this case report, QRS double counting in association with STEMI is documented for the first time. Healthcare workers who are monitoring patients with myocardial infarction should be aware of this misdiagnosis and able to recognize the pattern.