Comprehensive evaluation of clinical care in patients with cardiac implanted electronic devices and arrhythmias: action towards improved workflow and outcomes

Heart rhythm disorders contribute a great burden to modern healthcare, but new opportunities for optimal usage of resources and improved standards of care are available due to progress in technology. In particular, the diagnosis, treatment and follow-up of heart rhythm disorders is evolving with emergence of game-changing technologies. To maximise impact of these technological advances, appropriate identification of opportunities and integration into care delivery is needed. This thesis aims to address the following three specific areas in the field of heart rhythm disorders. First, to explore challenges for follow-up care of patients with a Cardiac Implantable Electronic Device (CIED). Second, to determine optimal CIED selection for patients requiring continuous heart rhythm monitoring. Last, to define the utility of modern digital technology for heart rhythm assessment with a focus on atrial fibrillation (AF) screening. Chapter 1 provides a review of the current literature surrounding these topics. Chapter 2 and 3 each present research studies investigating in-hospital services for CIED checks in the Emergency Department and in the pre- and post-scan setting of Magnetic Resonance Imaging. These studies provide granular, patient-level details of current healthcare service utilisation that can be used to identify opportunities for improved care delivery. Acknowledging the growing burden of healthcare utilisation for follow-up and analysis of CIEDs, Chapter 4 pivots towards understanding the role of optimal implant technology to maximize efficiency of resources. Research presented in this chapter assesses current generation implant devices to demonstrate differences in the electrograms that are obtained by insertable cardiac monitors (ICM) with different sensing vector length. Chapter 5 then explores the utility of a longer sensing vector, by proxy of surface electrocardiogram (ECG) tracings simulating ICM rhythm strips, for obtaining optimal electrogram sensing. This has implications for ICM selection in varying patients to optimise efficiency of continuous cardiac monitoring. The recent growth in personal ownership of digital devices, such as smartphones and watches, that are capable of heart rhythm monitoring has provided a feasible alternate option for arrhythmia detection. However, in comparison to implantable devices, these technologies broadly vary in their mechanism of rhythm detection, complexity and fidelity of data acquisition. The increasing accessibility of such wearable or portable digital technology presents a clinical conundrum for its appropriate utility in healthcare settings. Chapter 6 investigates the utility of portable digital technology, specifically that which can obtain single-lead ECG tracings and apply automated algorithms for arrhythmia detection, to screen for the most common heart rhythm disorder of atrial fibrillation (AF). Chapter 7 assesses the ability of such personal digital devices to identify AF even in low-resource communities. This body of work identifies opportunities where integration of emerging technologies in the management of heart rhythm disorders can guide strategic investment of expenditure and resource allocation to provide more efficient healthcare service that may improve patient outcomes.Thesis (Ph.D.) -- University of Adelaide, Adelaide Medical School, 202