The clinical utility of cross-spectral signals analysis in chest pain- Kieran Shivakumaarun
The clinical utility of cross-spectral signals analysis in chest pain
Atraumatic chest pain is one of the most common presenting complaints for patients in the Australian Emergency Department (ED), accounting for about 4% of all presentations. One of the most important differentials for this symptom is acute coronary syndrome (ACS), a potentially life-threatening series of conditions whose outcomes are significantly improved by rapid identification and management. In this study, we plan to explore the clinical utility of a novel technology, cross-spectral heart-rate variability (HRV) and photoplethysmogram variability (PPGV) analysis.
ACS can be broadly divided into three main categories, in increasing order of severity; unstable angina, non ST-elevated myocardial infarction, and ST-elevated myocardial infarction. These conditions are grouped under the umbrella term of ACS due to their common pathology of cardiac ischaemia. Rapid diagnosis and treatment results in improved cardiac perfusion, leading to better outcomes such as shorter ED length of stay and reduced mortality. However, the current diagnostic pathway in NSW, involving measurement of troponin levels and an electrocardiogram (ECG), requires more time than ideal for a definitive diagnosis, as troponin blood levels may only rise in the subacute phase of pathology.
Cross-spectral HRV/PPGV analysis involves the simultaneous analysis of the heart-rate variability tachogram, a wavelike graph obtained from the ECG which shows instantaneous heart rate, and the photoplethysmograph, a wavelike graph obtained by continuous monitoring of peripheral capillary blood oxygen saturation. Traditionally, both the ECG and the photoplethysmogram have been used to monitor vital signs and provide signs of acute patient deterioration. However, we propose that by examining minute variations in both graphs, we can assess for changes which are pathognomonic of an underlying ACS pathology, and thus develop a model which can use PPGV to assess for ACS in the wider ED setting.
Our study is being conducted though a convenience sampling methodology at Liverpool Hospital in Sydney, NSW. We are recruiting all patients above the age of 18 who present with atraumatic chest pain, and directly collecting basic information such as name and immediate medical history, along with 5-10 minute ECG and PPG recordings obtained from the fingertip and earlobe. We will be cross referencing this information with data stored on eMR FirstNet to analyse the correlation between our findings and the eventual ED diagnosis.