(S026) A Novel Method for Detecting Serious Cardiac Device Errors in Patients Receiving Radiotherapy Using Daily Pulse Checks

April 30, 2015

A novel method for monitoring CIEDs during radiotherapy is presented, which we report as effective, easy, and lacking adverse side effects. This simple technique is a cost-effective alternative to frequent device interrogations during the course of radiotherapy and allows for consistent daily monitoring.

Jonathan D. Grant, MD, Anne Dougherty, MD, Karimzad Kaveh, MD, Daniel R. Gomez, MD, Marc A. Rozner, PhD, MD; UT MD Anderson Cancer Center

INTRODUCTION: Little consensus exists for the proper monitoring of cardiac implantable electronic devices (CIEDs) in patients undergoing radiotherapy. We present data supporting a novel, easy, safe, and cost-effective method for detecting serious CIED problems arising during radiotherapy using daily heart rate (HR) monitoring.

MATERIALS AND METHODS: Since all CIEDs default to pacing at 60–72 beats per minute (bpm) without rate-response function (RRF) upon detection of a serious error, we instituted the following daily posttreatment pulse check protocol in 2010. Any patient who can be safely paced at a lower set rate of 75 bpm with RRF undergoes reprogramming at his preradiation CIED interrogation. Following each fraction of radiotherapy, these patients rest for 5 minutes and then undergo a pulse check. An HR of ≥ 74 bpm verifies the absence of a serious error. Because paroxysmal ventricular contractions may permit perfused pulses that register < 74 bpm, “tapping” on the CIED ensues to simulate patient exercise. An HR increase verifies the appropriate programming and the absence of a serious error. In a patient with an HR ≤ 73 and nonresponse to the tapping maneuver, a serious error is suspected, and a CIED interrogation is performed. At the completion of radiotherapy, device interrogation is performed for all patients, with return of the CIED to the appropriate settings.

RESULTS: Between February 2010 and October 2013, a total of 36 patients with CIEDs received treatment at the proton therapy center, 29 (81%) of whom were eligible for the pulse protocol. We found four patients (14%) with five serious CIED errors, manifested as a device parameter reset. A total of 845 fractions of radiotherapy were delivered in this cohort, giving an error rate per fraction of 0.6%. All affected patients were detected by a decrease in the measured HR of ≤ 73. No additional resets were discovered on any other device at routine posttreatment interrogation. No adverse events were experienced by any patient as a result of the increased lower pace rate. In one patient with HR < 74 bpm, the “tapping maneuver” confirmed the absence of a reset and prevented an unnecessary device interrogation.

CONCLUSIONS: A novel method for monitoring CIEDs during radiotherapy is presented, which we report as effective, easy, and lacking adverse side effects. This simple technique is a cost-effective alternative to frequent device interrogations during the course of radiotherapy and allows for consistent daily monitoring.

Proceedings of the 97th Annual Meeting of the American Radium Society- americanradiumsociety.org