Fluctuation in ventricular sensing leading to underdetection of ventricular fibrillation in a patient with cardiac sarcoidosis.

In this case report, we describe markedly fluctuating ventricular sensing through an implantable cardioverter defibrillator (ICD) over a period of 29 months in a patient with cardiac sarcoidosis. We conclude that the fluctuations in the measured R wave are the result of waxing and waning inflammation associated with sarcoid activity. The patient had a stable medical course throughout the time period studied, including stable immunosuppression and stable electrolytes. We believe this is an example of an important complication of ICD implants in patients with cardiac sarcoidosis and that frequent sensing evaluations are prudent in these patients.