A Comprehensive Examination of Single Channel ECG and Smartwatches for the Diagnosis and Detection of Arrhyhtmias - Superior

Abstract:

This report presents a two-phased investigation aimed at assessing the efficacy of 1-channel ECG signals and evaluating the capabilities of smartwatches in identifying Long QT Syndrome (LQTS) and other arrhythmias besides Atrial Fibrillation (Afib). The first phase evaluates the correctness of 1-channel ECG data by comparing them to the established 12-channel ECG standard. A thorough literature study is performed, and pertinent data on sensitivity, specificity, and accuracy are gathered. Statistical analyses are used to quantify these metrics, which include Heart Rate Variability (HRV), QTc time, RR Interval, PQ interval, Premature Ventricular Contractions (PVCs), Premature Atrial Contractions (PAVs), and rhythm analyses for Bigeminy, Trigeminy, various forms of Supraventricular Tachycardias (SVTs), and Sinus Tachycardia as a type of SVT. In the second phase, the investigation focuses on smartwatch capabilities for identifying cardiac problems. The existing research on smartwatch ECGs is reviewed, with a focus on sensitivity, specificity, and accuracy. The limitations and constraints described in the literature are identified, and the reliability of smartwatch readings is compared to standard ECG methods. The tiered approach provides a systematic advancement, laying a solid basis with a thorough comprehension of 1- channel ECG signals before entering the complex evaluation of smartwatches. This method is expected to produce better informed and effective results for the detection and monitoring of cardiovascular diseases. The review identified a lack of literature for automatic detection of Atrioventricular Nodal Reentrant Tachycardia (AVNRT) and Wolff-Parkinson-White syndrome (WPW syndrome) using single channel ECG as well as smart devices.

Introduction:

Heart rate variability (HRV) refers to the physiological variation of the interval between consecutive heart beats induced by autonomic nervous system activity. In the last decade, HRV analysis has been used to diagnose a variety of clinical and functional issues (Montano et al. 2009; Pumprla et al. 2002). Inter-beat intervals obtained from R waves in electrocardiograms (ECG) are commonly used for HRV studies (Laurin et al. 2013, Tadi et al.2015). The ECG period between the commencement of the P wave and the onset of the QRS complex is commonly referred to as the PR interval, although it should be referred to more precisely as the PQ interval. The duration of this period, as is widely known, represents the combination of intra-atrial conduction and excitation latency within the atrioventricular node (Toman et al. 2020). Premature contractions, also known as ectopic beats, are prevalent in healthy people and occur independently of the heart's physiological pacemaker. They are characterised as premature atrial or ventricular contractions (PACs and PVCs, respectively) according to their origin.

Bigeminy is distinguished by a normal heartbeat followed by an early contraction, resulting in a repeating pattern. A consistent coupling of normal and premature beats would be visible on an ECG. Trigeminy is characterised by a recurring pattern of two normal heartbeats followed by an early contraction. This results in a three-beat sequence on an ECG. Cardiac arrhythmias (CA) are a common health issue in industrialized and underdeveloped countries. The number of individuals impacted CA is likely to expand in the approaching years due to lifestyle changes and increased work pressure (Cardiovascular Diseases, 2021). Atrial fibrillation (AF), atrial flutter (Aflut), and AVNRT are all examples of Supra ventricular tachycardias (SVT). AF is a supraventricular cardiac arrhythmia marked by irregular and chaotic P-waves in the ECG (Martis et al., 2012). Although rarely life-threatening, this type of arrhythmia is a leading source of thrombus formation in the heart's upper chambers. Research indicates that patients with AF pathology are more likely to experience sudden cardiac arrest (Heart et al., 2006). AF causes irregular ventricular response, resulting in variations in clinical components of ECG, particularly the RR interval. AF typically has no effect on QRS width, although it might cause conduction abnormalities. Ventricular tachycardia (VT) is a ventricular arrhythmia characterized by extended QRS complexes (length 160 ms) (Soliman et al., 2014; Surawicz et. al, 2008). Wolff-Parkinson-White syndrome (WPW syndrome) is distinguished by an additional pathway between the atria and ventricles, which results in a quicker heartbeat. WPW has a short PR interval and a distinctive delta wave on an ECG. AV block is characterised by poor conduction between the atria and ventricles. A prolonged QT interval on the ECG indicates Long QT Syndrome, which increases the risk of life-threatening arrhythmias, including Torsades de Pointes

(Tester et al., 2014). Sinus tachycardia (ST) is characterised by a faster-than-normal heartbeat that originates from the sinus node. It appears as a regular rhythm with an accelerated heart rate on an ECG.