Approaching Long Term Cardiac Rhythm Monitoring Using Advanced Arm Worn Sensors and ECG Recovery Techniques

Abstract

According to recent British Heart Foundation statistics, one in six men and more than one in ten women die from coronary heart disease (CHD) in the UK. This equates to almost 74,000 deaths per annum from CHD alone.  More worryingly, every week, 12 apparently fit and healthy young people aged 35 and under, die from undiagnosed cardiac conditions. In both circumstances, monitoring is preformed only when triggered by an event. Unfortunately, this may be too late in the large majority of cases. For instance, there is evidence suggesting that most indiscernible cardiac abnormalities are made detectable by ECG through the act of suddenly standing upright. This infers that the condition would be detectable during the course of everyday ambulatory activity and highlights the need for a long term monitoring device. Current diagnostic equipment consists of the Holter monitor for extended periods up to 36 hours and the implantable loop recorder (ILR) for monitoring up to 3 years. The diagnostic yield of the ECG monitoring strategy is greatly increased as the monitoring period increases. Therefore, for subjects that exhibit symptoms of cardiac involvement that are transient in nature, the ILR offers the best opportunity for diagnosis. However, the ILR is inserted under the surface of the skin in the upper chest area and requires a surgical procedure, with associated risks, which makes ILR’s a costly and inconvenient option in many cases. The need for a non-invasive long term monitoring device, which is comfortable to wear along the arm and able to provide reliable ECG monitoring, has been addressed by many, in several lines of approach to a solution. This review details the current state of the art and any pending limitations. It then presents key multidisciplinary solutions on the different aspects of the problem, which will still require integration in order to realise such a device.