Psychological indices and phantom shocks in patients with ICD

Some patients with ICDs experience the sensation of a shock in the absence of true therapy (phantom shock). We hypothesize that phantom shocks may be a manifestation of anxiety, depression or PTSD.

All patients over 18 years old with an ICD were eligible to enroll in the study. The first 75 subjects who agreed to participate were enrolled and divided into three groups: ICD patients with phantom shocks (n = 19); ICD patients who had actual shocks (n = 28) and ICD patients who had no shocks (n = 28). During a clinic visit a demographic questionnaire and three psychological rating scales were administered: the Spielberger State-Trait Anxiety Inventory (STAI); the Center for Epidemiologic Studies Depression Scale (CES-D) and the Posttraumatic Stress Checklist (PCL-C). No significant differences between groups were found in gender, race, age, history of MI or cardiac surgery status. Data analysis of the psychological indices using one-way ANOVA showed that the group with phantom shocks had more depression (CES-D p = 0.011) and more anxiety (STAI p = 0.010) than the other groups. Multiple comparisons of group means showed a greater percentage of clinically depressed patients in the phantom shock group than in the other groups.

Patients with phantom shocks are more likely to be clinically depressed and have higher levels of anxiety than other ICD patients, regardless of history of actual shocks.