Objective  

To describe the clinical course of a patient with multiple ICD shocks in the setting of advanced renal failure and hyperkalemia.

Methods  

The patient was brought to the Electrophysiology Laboratory where the ICD was interrogated.

Results  

The patient was found to be hyperkalemic (serum potassium 7.6 mg/dl). Analysis of stored intracardiac electrograms from the ICD revealed “triple counting” (twice during his QRS complex and once during the T wave) and multiple inappropriate shocks. Correction of his electrolyte abnormality normalized his electrogram and no further ICD activations were observed.

Conclusion  

Electrolyte abnormalities can distort the intracardiac electrogram in patients with ICD’s and these changes can lead to multiple inappropriate shocks.