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Cardioversion is a medical procedure by which an abnormally fast heart rate (tachycardia) or other cardiac arrhythmia is converted to a normal rhythm using electricity or drugs. Synchronized electrical cardioversion uses a therapeutic dose of electric current to the heart at a specific moment in the cardiac cycle, restoring the activity of the electrical conduction system of the heart. Pharmacologic cardioversion, also called chemical cardioversion, uses antiarrhythmia medication instead of an electrical shock.
Sinus node dysfunction (SND), also known as sick sinus syndrome (SSS), is a group of abnormal heart rhythms (arrhythmias) usually caused by a malfunction of the sinus node, the heart's primary pacemaker. Tachycardia-bradycardia syndrome is a variant of sick sinus syndrome in which the arrhythmia alternates between fast and slow heart rates.
The New York Heart Association (NYHA) Functional Classification provides a simple way of classifying the extent of heart failure. It places patients in one of four categories based on how much they are limited during physical activity; the limitations/symptoms are in regard to normal breathing and varying degrees in shortness of breath and/or angina.
Short QT syndrome (SQT) is a very rare genetic disease of the electrical system of the heart, and is associated with an increased risk of abnormal heart rhythms and sudden cardiac death. The syndrome gets its name from a characteristic feature seen on an electrocardiogram (ECG) – a shortening of the QT interval. It is caused by mutations in genes encoding ion channels that shorten the cardiac action potential, and appears to be inherited in an autosomal dominant pattern. The condition is diagnosed using a 12-lead ECG. Short QT syndrome can be treated using an implantable cardioverter-defibrillator or medications including quinidine. Short QT syndrome was first described in 2000, and the first genetic mutation associated with the condition was identified in 2004.
Ventricular tachycardia is a fast heart rate arising from the lower chambers of the heart. Although a few seconds of VT may not result in permanent problems, longer periods are dangerous; and multiple episodes over a short period of time are referred to as an electrical storm. Short periods may occur without symptoms, or present with lightheadedness, palpitations, or chest pain. Ventricular tachycardia may result in ventricular fibrillation (VF) and turn into cardiac arrest. This conversion of the VT into VF is called the degeneration of the VT. It is found initially in about 7% of people in cardiac arrest.
Familial atrial fibrillation is an autosomal dominant heart condition that causes disruptions in the heart's normal rhythm. This condition is characterized by uncoordinated electrical activity in the heart's upper chambers, which causes the heartbeat to become fast and irregular.
The CHADS2 score and its updated version, the CHA2DS2-VASc score, are clinical prediction rules for estimating the risk of stroke in people with non-rheumatic atrial fibrillation (AF), a common and serious heart arrhythmia associated with thromboembolic stroke. Such a score is used to determine whether or not treatment is required with anticoagulation therapy or antiplatelet therapy, since AF can cause stasis of blood in the upper heart chambers, leading to the formation of a mural thrombus that can dislodge into the blood flow, reach the brain, cut off supply to the brain, and cause a stroke.
Tedisamil (3,7-dicyclopropylmethyl-9,9-tetramethylene-3,7-diazabicyclo-3,3,1-nonane) is an experimental class III antiarrhythmic agent currently being investigated for the treatment of atrial fibrillation. Tedisamil blocks multiple types of potassium channels in the heart resulting in slowed heart rate. While the effects of tedisamil have been demonstrated in both atrial and ventricular muscle, repolarization is prolonged more efficiently in the atria. Tedisamil is administered intravenously and has a half-life of approximately 8 –13 hours in circulation. Tedisamil is being developed as an alternative to other antiarrhythmics as incidence of additional arrhythmic events is lower compared to other class III agents. Tedisamil also has significant anti-ischemic properties and was initially investigated as a potential treatment for angina until its antiarrhythmic effects were discovered. Tedisamil is manufactured by Solvay Pharmaceuticals Inc. under the proposed trade name Pulzium.
Vernakalant is a pharmaceutical drug for the acute conversion of atrial fibrillation, a kind of irregular heartbeat, in form of an intravenous infusion. It has been approved for use in the European Union and the UK since 2010. The US Food and Drug Administration denied approval in 2008 and 2019.
Atrial fibrillation is an abnormal heart rhythm (arrhythmia) characterized by rapid and irregular beating of the atrial chambers of the heart. It often begins as short periods of abnormal beating, which become longer or continuous over time. It may also start as other forms of arrhythmia such as atrial flutter that then transform into AF. Episodes can be asymptomatic. Symptomatic episodes may involve heart palpitations, fainting, lightheadedness, shortness of breath, or chest pain. Atrial fibrillation is associated with an increased risk of heart failure, dementia, and stroke. It is a type of supraventricular tachycardia.
Roemheld syndrome (RS), or gastrocardiac syndrome, or gastric cardiac syndrome or Roemheld-Techlenburg-Ceconi-Syndrome or gastric-cardia, was a medical syndrome first coined by Ludwig von Roemheld (1871–1938) describing a cluster of cardiovascular symptoms stimulated by gastrointestinal changes. Although it is currently considered an obsolete medical diagnosis, recent studies have described similar clinical presentations and highlighted potential underlying mechanisms.
The management of atrial fibrillation (AF) is focused on preventing temporary circulatory instability, stroke and other ischemic events. Control of heart rate and rhythm are principally used to achieve the former, while anticoagulation may be employed to decrease the risk of stroke. Within the context of stroke, the discipline may be referred to as stroke prevention in atrial fibrillation (SPAF). In emergencies, when circulatory collapse is imminent due to uncontrolled rapid heart rate, immediate cardioversion may be indicated.
Arrhythmias, also known as cardiac arrhythmias, heart arrhythmias, or dysrhythmias, are irregularities in the heartbeat, including when it is too fast or too slow. A resting heart rate that is too fast – above 100 beats per minute in adults – is called tachycardia, and a resting heart rate that is too slow – below 60 beats per minute – is called bradycardia. Some types of arrhythmias have no symptoms. Symptoms, when present, may include palpitations or feeling a pause between heartbeats. In more serious cases, there may be lightheadedness, passing out, shortness of breath or chest pain. While most cases of arrhythmia are not serious, some predispose a person to complications such as stroke or heart failure. Others may result in sudden death.
Cardiac contractility modulation is a therapy which is intended for the treatment of patients with moderate to severe heart failure with symptoms despite optimal medical therapy who can benefit from an improvement in cardiac output. The short- and long-term use of this therapy enhances the strength of ventricular contraction and therefore the heart's pumping capacity by modulating (adjusting) the myocardial contractility. This is provided by a pacemaker-like device that applies non-excitatory electrical signals adjusted to and synchronized with the electrical action in the cardiac cycle.
Budiodarone (ATI-2042) is an antiarrhythmic agent and chemical analog of amiodarone that is currently being studied in clinical trials. Amiodarone is considered the most effective antiarrhythmic drug available, but its adverse side effects, including hepatic, pulmonary and thyroid toxicity as well as multiple drug interactions, are discouraging its use. Budiodarone only differs in structure from amiodarone through the presence of a sec-butyl acetate side chain at position 2 of the benzofuran moiety. This side chain allows for budiodarone to have a shorter half-life in the body than amiodarone which allows it to have a faster onset of action and metabolism while still maintaining similar electrophysiological activity. The faster metabolism of budiodarone allows for fewer adverse side effects than amiodarone principally due to decreased levels of toxicity in the body.
An AF-Nest or Atrial Fibrillation Nest (AFN) is a locus or cluster in the atrial wall with distinct electrical features and properties originated by fibrillar myocardium. It plays as an "electrical multiplier" re-feeding the atrial fibrillation.
Topera, Inc. is a cardiac arrhythmia mapping company for targeting catheter ablation company launched in San Diego, California and specializes in mapping electrical signals of the heart. Topera's headquarters are located in Palo Alto, California. The company uses 3D analysis and mapping to detect the sources of atrial fibrillation, atrial flutter, and atrial tachycardia and ventricular tachycardia to identify targets for catheter ablation.
Yaariv Khaykin is a Canadian cardiologist and a clinical researcher in the area of electrophysiology. He is the director of the Newmarket Electrophysiology Research Group at the Southlake Regional Health Centre. He has published research into complex ablation and pioneered cardiac ablation methods.
Prof. Aly Saad, is a professor of cardiology at Zagazig University and a Member of higher committee of promotion of professors and Assistant professors of cardiovascular diseases and Critical care Subspecialty in Egypt.
References
- 1 2 Kirchhof, Paulus; Auricchio, Angelo; Bax, Jeroen; Crijns, Harry; Camm, John; Diener, Hans-Christoph; Goette, Andreas; Hindricks, Gerd; Hohnloser, Stefan (November 2007). "Outcome parameters for trials in atrial fibrillation: recommendations from a consensus conference organized by the German Atrial Fibrillation Competence NETwork and the European Heart Rhythm Association". Europace. 9 (11): 1006–1023. doi: 10.1093/europace/eum191 . ISSN 1532-2092. PMID 17897925.