Utility of the Audible Alert in Current Generation Medtronic Implantable Cardioverter-defibrillators

Overview

The purpose of this study is to determine whether the alert tones emitted by the latest generation of Medtronic implantable cardioverter-defibrillators (ICDs) are audible to patients. ICD patients can have difficulties hearing the beeps, which are designed to notify patients of possible lead or generator malfunction. In fact, the only published study of this issue, conducted at Englewood Hospital and Medical Center, revealed that only 50% of patients with older Medtronic devices were able to hear alerts. Since then, modifications to the alert have been made by Medtronic. This study will establish the "real-world" value of these changes and also provide useful in vivo information regarding the validity of the in vitro techniques which have been used thus far to design the Patient Alert feature.

There will be a single study visit. In a quiet examination room, the Patient Alert tones will be demonstrated to the subjects. Subsequently, this will be repeated with a wall air conditioner turned on. The subjects will then be asked to complete a three-part questionnaire regarding their perceptions of the Patient Alert tones. Data analysis will include overall ability to hear tones, as well as subgroup analysis according to gender, age, and BMI. Simultaneously, in order to calculate the loudness of the alert tones, digital recordings will be obtained using two microphones located near the subject. These digital recordings will be analyzed, and a loudness value will be calculated. The loudness value is a calculated index, devised by Medtronic, which incorporates frequency and intensity. Data analysis will include a correlation between loudness value and patient characteristics, and between loudness value and ability of subjects to perceive the tones.

Conditions