Sporadic high pacing and shock impedance on remote monitoring in hybrid implantable cardioverter-defibrillator systems: Clinical impact and management

A mobile app for improving the compliance with remote management of patients with cardiac implantable devices: a multicenter evaluation in clinical practice

BACKGROUND

The remote device management (RM) is recommended for patients with cardiac implantable electronic devices (CIEDs). RM underutilization is frequently driven by the lack of correct system activation. The MyLATITUDE Patient App (Boston Scientific) has been developed to encourage patient compliance with RM by providing information on communicator setup, troubleshooting, and connection status of the communicator.

METHODS

At 14 centers, patients with CIEDs were invited to download and install the App on a mobile device. After 3 months, patients were asked to complete an ad hoc questionnaire to evaluate their experience.

RESULTS

The App was proposed to 242 consecutive patients: 81 before RM activation, and 161 during follow-up. The App was successfully installed by 177 (73%) patients. The time required for activation of the communicator and the need for additional support were similar between patients who followed the indications provided by the App and those who underwent standard in-clinic training. During follow-up, notifications of lack of connection were received by 20 (11%) patients and missed transmission by 22 (12%). The median time from notification to resolution was 2 days. After 3 months, 175 (99%) communicators of the 177 patients who installed the App were in "Monitored" status versus 113 (94%) of 120 patients without the App installed (p=0.033). The use of the app made 84% of patients feel reassured.

CONCLUSIONS

The App was well accepted by CIED patients and offered support for communicator management and installation. Its use enabled patients to remain connected with greater continuity during follow-up.

Impact of COVID-19 Pandemic on Cardiac Electronic Device Management and Role of Remote Monitoring

During the coronavirus disease 2019 (COVID-19) worldwide pandemic, patients with cardiac implantable electronic device (CIED) refused scheduled follow-up visits because of the risk of infection. In this scenario, different telemedicine strategies have been implemented to ensure continuity of care to CIED patients. Patients can be monitored through dedicated applications, telephone calls, or virtual visits providing easy access to valuable information, such as arrhythmic events, acute decompensation manifestations, and device-related issues, without the need for in-person visits. This review provides a comprehensive description of the many possible applications of telemedicine for CIED patients during the COVID-19 period.

Interpreting device diagnostics for lead failure

Implantable cardioverter-defibrillators (ICDs) incorporate automated, lead-monitoring alerts (alerts) and other diagnostics to detect defibrillation lead failure (LF) and minimize its adverse clinical consequences. Partial conductor fractures cause oversensing, but pacing or high-voltage alerts for high impedance detect only complete conductor fracture. In both pacing and high-voltage insulation breaches, low-impedance alerts require complete breach with metal-to-metal contact. Oversensing alerts for pace-sense LF also require complete breach, but not metal-to metal contact. Electrograms (EGMs) from leads with confirmed fractures have characteristics findings. In insulation breach, however, oversensed EGMs reflect characteristics of the source signal. Oversensing alerts that operate on the sensing channel analyze R-R intervals for 2 patterns typical of LF but uncommon in other conditions: a rapidly increasing count of "nonphysiological" short intervals and rapid "nonsustained tachycardias." These alerts are sensitive but nonspecific. Alerts that compare sensing and shock channels define oversensing as sensed events that do not correlate temporally with EGMs on the shock channel. Their performance depends on implementation. Specific advantages and limitations are reviewed. Most ICDs measure impedance using subthreshold pulses. Patterns in impedance trends provide diagnostic information, whether or not an alert is triggered. Gradual increases in impedance do not indicate structural LF, but they may cause failed defibrillation if shock impedance is high enough. Because impedance-threshold alerts are insensitive, normal impedance trends never exclude LF, but an abrupt increase that triggers an alert almost always indicates a header connection issue or LF. Methods for discriminating connection issues from LF are reviewed.