Causes of Failure to Capture in Pacemakers and Implantable Cardioverter-defibrillators.

Ebrahim Sabbagh,Thaer Abdelfattah,Amjad Farah,Blair Grubb,Mohammad Karim,Saima Karim

doi:10.19102/icrm.2020.110207

Abstract

The number of patients with implantable electronic cardiac devices is continuously increasing. As more pacemakers and implantable cardioverter-defibrillators (ICDs) are being placed, a basic understanding of some troubleshooting for devices is becoming essential. Loss of capture can be an emergent presentation for an unstable patient and can be encountered intermittently in hospitalized patients. There are many causes for a loss of capture, with the timing of the implant having a high correlation with certain causes over others. The most common acute cause just after the insertion procedure is lead dislodgement or malposition. In comparison, an increase in the required threshold promoting a loss of capture can happen after months to years of insertion of the pacemaker or ICD. This change can be due to a cardiomyopathy, fibrosis medications, metabolic imbalance, lead fracture, or an exit block. Loss of capture can also occur from external electrical stimuli and inappropriate pacemaker or ICD settings. Further, there are also potential noncardiac causes, such as medications, electrolyte imbalance, and acidemia. A knowledge of these factors is essential for health care providers, given the morbidity and mortality that can potentially be associated with device-related issues, especially in patients who are dependent on the included pacing function.

Highlights

The number of patients with implantable cardiac devices is continuously increasing.[1,2] Health-care providers have frequent interactions with patients with pacemakers and implantable cardioverter-defibrillators (ICDs)
Understanding the cause of loss of capture in pacemakers and ICDs is crucial for the prevention of morbidity, mortality, and inappropriate treatment
Consideration of the timeline from the implant procedure to the time of the loss of capture is important in determining the cause

Summary

Introduction

The number of patients with implantable cardiac devices is continuously increasing.[1,2] Health-care providers have frequent interactions with patients with pacemakers and implantable cardioverter-defibrillators (ICDs). There is a frequent need for the evaluation of these devices for the clinical benefit of monitoring the patient’s rhythm abnormalities and events that have occurred, along with the need for therapy.[2,3] it is important to be able to assess arrhythmias and perform device management, physicians should be aware of device and lead malfunctions and failures.[3,4] Pacemaker and ICD lead malfunctions can be classified based on the electrocardiogram signs into the following groups: loss of capture, inadequate output, undersensing or oversensing, inappropriate pacing, pacemaker-mediated tachycardia, and issues with battery life. An acute loss of capture in dependent patients requires hospitalization and either reprogramming of the device at a very high output (often asynchronously) with telemetry monitoring or the insertion of a temporary pacing system until the underlying issue can be resolved emergently

Findings

Discussion

Conclusion