Background: Although crucial, research on nurses' knowledge on the use of implantable cardioverter defibrillators (ICDs) is scant. The aims of the study were to investigate (i) the level of nurses' knowledge on care of patients with ICDs, (ii) whether knowledge level is related to education and type of hospital where nurses practice and (iii) whether knowledge level changes among nurses over time.

Methods: We developed a questionnaire comprising 27 items in four parts: (1) Sociodemographics, (2) Technical facts about ICDs, (3) Daily life challenges and (4) Self-evaluation of knowledge. After validation, surveys were conducted during 1-week cardiac educational courses in 2003–2010. In total, 463 nurses working in cardiology-related areas participated, yielding a response rate of 91%.

Results: Practical and technical knowledge about ICDs was lacking. Nurses were unaware or did not know that mobile phones can affect the device (80%), that patients are restricted from driving heavy vehicles (69%), and that ICDs can deliver unintended shock therapy (73%). However, they were aware that ICD patients can resume sexual (87%) and physical activity (85%). There were few significant differences with regard to education and type of hospital where nurses practiced, but significant time trends in correct answers regarding kitchen appliances, resumption of physical activity and shock delivery.

Conclusion: Over an 8-year period, despite the increased usage of ICDs, overall nurses had a lack of knowledge in relation to specific key clinical issues on the care of ICD patients. As a consequence, these patients may fail to receive qualified care. Future research should assess knowledge of other health care professionals and focus on interventions that increase and maintain an appropriate knowledge level in care of ICD patients.

Relevance to clinical practice: The level of nurses' knowledge on care of patients with ICDs needs to be systematically raised in order to ensure appropriate counselling and nursing care.