Recognition of Cardiac Arrhythmia by Means of Beat Clustering on ECG-Holter Recordings 3 Cardiac arrhythmiasIn general, the pathologies observed using the ECG are divided into three categories:1. Heart rhythm disturbances, or arrhythmias.2. Dysfunctions of blood perfusion in the myocardium or cardiac ischemia.3. Chronic disorders of mechanical structure of the heart, such as left ventricular hypertrophy.We will describe the characterization and identification of the first type of pathologies above mentioned.The methods are developed over the entire QRS complexes that are associated with ventricular electrical activity.They contain clinic important information, for example their morphology has significant changes in abnormal ventricular heartbeats.QRS complexes are also present in most of the heartbeats and their signal to noise ratio is the highest among all waves present in the signal. Not imminently life-threatening cardiac arrhythmiasBroadly speaking, arrhythmias can be divided into two groups: The first group includes ventricular fibrillation and tachycardia, which are life-threatening disorders and require immediate therapy with a defibrillator.Identification of these arrhythmias and successful detectors have been developed with high sensitivity and specificity degree.However, this study just analyzes the second group, which includes arrhythmias that are not imminently life-threatening but may require therapy to prevent further problems.According to the AAMI standard (ANSI/AAMI EC57:1998/(R)2003) as is described in De-Chazal et al. (2004), the following arrhythmia groups shown in Table 1 are of interest to be examined: Normal-labeled heartbeat recordings (termed N), Supraventricular ectopic beat (Sv), Ventricular ectopic beat (V), Fusion beat (F), as well as unknown beat class (Q) are taken into consideration.One or more classes of such arrhythmias can be present during Holter analysis.The MIT/BIH arrhythmia database Moody & Mark (1982) is one of the most representatives, at a scientific level, to evaluate the design of algorithms regarding the analysis of cardiac arrythmias.The database contains several types of beats within each group of arrhythmias recommended by the AAMI, for example, in the Normal group we can find the following arrhythmia types: Left bundle Branch Block (LBBB), Right Bundle Branch Block (RBBB), Atrial Escape (AE) and junctional Nodal Escape (NE).The Table 1 shows a classification of arrhythmias previously mentioned. Group of arrhythmias N How to referenceIn order to correctly reference this scholarly work, feel free to copy and paste the following: