Bioelectric and Biomagnetic Signal Analysis
Arvind Kumar Bansal, Javed Iqbal Khan, S. Kaisar Alam in Introduction to Computational Health Informatics, 2019
Arrhythmia is a common problem in old age. The heartbeat becomes irregular in arrhythmia. Heartbeat can either slow down or speed up. Bradycardia is a subclass of arrhythmia when the rate of heartbeats slows down. Tachycardia is another subclass of arrhythmia when the heartbeat speeds up. Tachycardia is divided into two subclasses: 1) supraventricular arrhythmia caused by abnormalities in the atria and 2) ventricular arrhythmia caused by abnormalities in the ventricles. Three major problems cause irregular heartbeats: 1) abnormality in ion-channels of heart cells that disturb the depolarization cycle of the SA-node and/or heart-cells; 2) change in the origin of the electrical activity in the heart and 3) fibrillation of heart-muscles. Fibrillation causes: 1) random alignment in heart-muscles disorienting the regular electrical pattern and 2) fibrous tissues that become an alternate source of irregular electrical activities in addition to the SA-node.
Positional and Restraint Asphyxia
Darrell L. Ross, Gary M. Vilke in Guidelines for Investigating Officer-Involved Shootings, Arrest-Related Deaths, and Deaths in Custody, 2018
When a sudden, unexpected death occurs in such cases, it is important to consider whether the likely cause was respiratory or cardiac. Sudden cardiac death is defined as originating from cardiac etiology and is often brought on by a sudden and abrupt loss of consciousness within one hour of the onset of acute symptoms (Myerburg & Castellanos, 2005). The National Heart, Lung, and Blood Institute (NHLBI) describes the signs and symptoms of sudden cardiac arrest as including a loss of consciousness, a racing heartbeat, dizziness, and chest pain/shortness of breath, all within an hour of sudden cardiac arrest (National Heart, Lung, and Blood Institute, 2015). The most common cause is cardiac ischemia, causing an arrhythmia, termed ventricular fibrillation (V-fib) (Koplan & Stevenson, 2009). While underlying morbidity and co-morbid factors (e.g., diabetes, renal function, electrolyte levels) are contributing factors to the etiology of ventricular fibrillation, it is thought that left ventricular hypertrophy (LVH) is the leading contributing factor involved in sudden cardiac death in the adult population (Stevens, Reineir, & Chugh, 2013). The structural hypertrophy and non-compliance of the heart is associated as the underlying cause for increased cardiac irritability, arrhythmia, and, ultimately, by entering ventricular fibrillation, lost perfusion to the heart and brain, thereby leading to death.
Cardiac Arrythmias
Charles Theisler in Adjuvant Medical Care, 2023
An arrythmia refers to any change from the normal sequence of electrical impulses that affects either the rate or rhythm of the heartbeat. Irregular heartbeats such as atrial fibrillation, bradycardia, tachycardia, conduction disorders, rhythm disorders, ventricular fibrillation, and premature contractions are arrythmias, also known as dysrhythmias. Palpitations are disturbances in the rhythm that can be felt and can make the heart feel like it is beating too hard or too fast, skipping a beat, or fluttering. Symptoms and signs of arrhythmia often include chest pain, dizziness, breathlessness, palpitations, fainting, chest fluttering, tachycardia or bradycardia, and shortness of breath. Arrythmia is the most common cause of sudden cardiac arrest. There are a wide variety of causes for arrythmias, such as myocardial infarction, coronary heart disease (CAD), hypertension (HTN), thyroid problems, drug abuse, diabetes, certain medications, etc. Smoking and excessive alcohol or caffeine use also increase the risk of an arrythmia.
Identification of Swimmers in Distress Using Unmanned Aerial Vehicles: Experience at the Mont-Tremblant IRONMAN Triathlon
Published in Prehospital Emergency Care, 2020
Valerie Homier, François de Champlain, Michael Nolan, Richard Fleet
A triathlon involves a swim leg (750–3,800 m), followed by a bicycle leg (20–180 km), and a run (5–42 km). The mortality rate for triathletes is 1.7 per 100,000, with the majority of deaths occurring during the swim leg (16, 17). The exact cause of sudden death during the swim portion remains elusive. Cardiac arrhythmia is the most likely cause, although this is not definitive as the quality of available studies is limited (16, 18). In addition, cases of swimming-induced pulmonary edema (SIPE) can occur within minutes of the swim start (16). Triathletes run the risk of rapidly losing consciousness and disappearing in a crowd of swimmers, especially at the race start, and it can be challenging for lifeguards to distinguish victims amongst a large group of swimmers. Early identification of swimmers in distress is becoming a growing priority (19).
Focus on cardiac rhythm disorders
Published in Acta Cardiologica, 2023
Patrizio Lancellotti, Caroline Piette
Myocardial ischaemia is a common cause of arrhythmia, and the potential mechanism of ischaemic arrhythmia is quite complex and diverse. At present, in animal experiments, arrhythmia models can be constructed through a variety of methods, which are associated with high scientific research costs, high technical difficulty, complicated operation, low survival rate of the experimental animals, and poor reproducibility. Guo et al. showed in a rat model that the combination of subcutaneous and intraperitoneal injections of isoproterenol is more likely to induce arrhythmia than a single injection route [9]. Differential diagnosis of broad QRS tachycardia with left (L) BBB morphology is broad. The analysis of its response to adenosine can allow to make a correct diagnosis. The acceleration of tachycardia with disappearance of LBBB can indicate the presence of an accessory pathway (AP) on the ipsilateral side. However, this is not a phenomenon one would expect as a response to adenosine, which would most likely terminate such tachycardia [10]. Frequent junctional beats occurring in bigeminy are extremely rare. In very unusual situations, these ectopies may be responsible for a retrograde, but also an anterograde block, leading to a pseudo paroxysmal atrioventricular bloc [11, 12].
A review of arrhythmia detection based on electrocardiogram with artificial intelligence
Published in Expert Review of Medical Devices, 2022
Jinlei Liu, Zhiyuan Li, Yanrui Jin, Yunqing Liu, Chengliang Liu, Liqun Zhao, Xiaojun Chen
Electrocardiogram (ECG) is one of the recommended techniques for detecting arrhythmia. The complete ECG heartbeat contains three key waves: P-wave, QRS-wave, and T-wave, as shown in Figure 1. Different types of arrhythmia correspond to various wave shapes and periods [4], and an experienced cardiologist can quickly make a diagnosis based on the ECG. The widespread application of various ECG devices, especially wearable ECG monitors, has resulted in a large number of ECGs waiting to be diagnosed. However, it is a time-consuming and challenging task to perform arrhythmia analysis on ECG manually. The rapid application of artificial intelligence (AI) technology provides new opportunities for automatic detection of arrhythmia and assists physicians in accurately diagnosing cardiac diseases. Meanwhile, AI methods have also been applied to other physiological signals, such as Electromyogram (EMG), Electroencephalogram (EEG), and Electrooculogram (EOG) [5]. It is comparatively convenient to obtain ECG and the theory of ECG diagnosis of cardiac disease is relatively well established. Aiming at thousands of ECG data, AI methods can automatically learn the inherent patterns between features to achieve rapid and reliable disease classification [6]. Hence, the investigation and application of arrhythmia detection based on AI are of great importance.
Related Knowledge Centers
- Bradycardia
- Cardiac Cycle
- Chest Pain
- Heart Rate
- Lightheadedness
- Palpitations
- Shortness of Breath
- Syncope
- Tachycardia
- Signs & Symptoms
- Shortness of Breath