New tool evaluates patients' anxiety and fears about implantable cardioverter defibrillator shock

Implantable heart devices are the treatment of choice for patients with potentially life-threatening irregular heartbeats. But the thought of receiving a high-energy shock to restore normal cardiac rhythm can strike fear in their hearts nonetheless.

Now a new tool from the University of Florida can help health-care providers identify which patients may need psychological services to cope with anxiety. It's called the Florida Shock Anxiety Scale, and University of Florida researchers report on its effectiveness in the current issue of Pacing and Clinical Electrophysiology.

The Implantable Cardioverter Defibrillator (ICD) is a battery-powered device that constantly monitors the patient's heartbeat and delivers a 750-volt shock to restore normal rhythm if it senses a dangerous rapid rhythm developing. Approximately 150,000 patients worldwide received an ICD in 2004, according to researchers at the University of Marburg in Germany.

Patients' concerns about ICDs recently gained national attention after manufacturers recalled 109,000 defibrillators last year. Device flaws have been linked to at least seven deaths.

"Patients with an Implantable Cardioverter Defibrillator (ICD) can have unique fears that separate them from people with other general anxieties," said Emily Kuhl, the study's lead author and a doctoral candidate in the department of clinical and health psychology. "Patients with an ICD may be afraid that if the device fires they may harm themselves or others, or create a scene. Or, they may be fearful that certain activities, such as exercise or sexual activity, might trigger a shock."

Research has shown that 10 percent to 38 percent of ICD recipients will experience a shock within the first year of receiving the implant. The sensation is often described as feeling like a kick in the chest.

"Patients usually describe a shock as a six on a pain scale of one to 10," Kuhl said. "A shock is not so much painful as it is surprising. Chances are that a shock won't interfere to the point that a patient is unsafe to drive or care for children."

To test its effectiveness, UF researchers administered the Florida Shock Anxiety Scale, a written questionnaire, to 72 ICD recipients. The patients rated the frequency of anxious thoughts, such as "I am afraid of being alone when the ICD fires and I will need help" and "I am afraid to touch others for fear that I will shock them if the ICD fires."

Researchers analyzed participants' responses and determined that the scale evaluates the correct underlying anxiety concepts and proved highly reliable.

"We want to get the Florida Shock Anxiety Scale into the hands of health-care providers so they use it, understand it and realize how important it is," Kuhl said, adding that psychological treatment for ICD patients is not standard care in the United States.

Patient education is the key to helping patients overcome fears about receiving an ICD. By implementing the Florida Shock Anxiety Scale, physicians can tailor care to individually treat patient concerns.