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Proarrhythmia is a new or more frequent occurrence of pre-existing arrhythmias, paradoxically precipitated by antiarrhythmic therapy, which means it is a side effect associated with the administration of some existing antiarrhythmic drugs, as well as drugs for other indications. In other words, it is a tendency of antiarrhythmic drugs to facilitate emergence of new arrhythmias.
According to the Vaughan Williams classification (VW) of antiarrhythmic drugs, there are 3 main types of Proarrhythmia during treatment with various antiarrhythmic drugs for Atrial Fibrillation or Atrial flutter:
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.
Tachycardia, also called tachyarrhythmia, is a heart rate that exceeds the normal resting rate. In general, a resting heart rate over 100 beats per minute is accepted as tachycardia in adults. Heart rates above the resting rate may be normal or abnormal.
Palpitations are perceived abnormalities of the heartbeat characterized by awareness of cardiac muscle contractions in the chest, which is further characterized by the hard, fast and/or irregular beatings of the heart.
Antiarrhythmic agents, also known as cardiac dysrhythmia medications, are a group of pharmaceuticals that are used to suppress abnormal rhythms of the heart, such as atrial fibrillation, atrial flutter, ventricular tachycardia, and ventricular fibrillation.
Atrial flutter (AFL) is a common abnormal heart rhythm that starts in the atrial chambers of the heart. When it first occurs, it is usually associated with a fast heart rate and is classified as a type of supraventricular tachycardia. Atrial flutter is characterized by a sudden-onset (usually) regular abnormal heart rhythm on an electrocardiogram (ECG) in which the heart rate is fast. Symptoms may include a feeling of the heart beating too fast, too hard, or skipping beats, chest discomfort, difficulty breathing, a feeling as if one's stomach has dropped, a feeling of being light-headed, or loss of consciousness.
Dofetilide is a class III antiarrhythmic agent. It is marketed under the trade name Tikosyn by Pfizer, and is available in the United States in capsules containing 125, 250, and 500 µg of dofetilide. It is not available in Europe or Australia. In the United States it is only available by mail order or through specially trained local pharmacies.
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.
Amiodarone is an antiarrhythmic medication used to treat and prevent a number of types of irregular heartbeats. This includes ventricular tachycardia (VT), ventricular fibrillation (VF), and wide complex tachycardia, as well as atrial fibrillation and paroxysmal supraventricular tachycardia. Evidence in cardiac arrest, however, is poor. It can be given by mouth, intravenously, or intraosseously. When used by mouth, it can take a few weeks for effects to begin.
Ventricular tachycardia is a type of regular, fast heart rate that arises from improper electrical activity in the ventricles of the heart. Although a few seconds may not result in problems, longer periods are dangerous. Short periods may occur without symptoms, or present with lightheadedness, palpitations, or chest pain. Ventricular tachycardia may result in ventricular fibrillation and turn into sudden death. It is found initially in about 7% of people in cardiac arrest.
Supraventricular tachycardia (SVT) is an abnormally fast heart rhythm arising from improper electrical activity in the upper part of the heart. There are four main types: atrial fibrillation, paroxysmal supraventricular tachycardia (PSVT), atrial flutter, and Wolff–Parkinson–White syndrome. Symptoms may include palpitations, feeling faint, sweating, shortness of breath, or chest pain.
Sotalol, sold under the brand name Betapace among others, is a medication used to treat and prevent abnormal heart rhythms. It is only recommended in those with significant abnormal heart rhythms due to potentially serious side effects. Evidence does not support a decreased risk of death with long term use. It is taken by mouth or injection into a vein.
Azimilide is a class ΙΙΙ antiarrhythmic drug. The agents from this heterogeneous group have an effect on the repolarization, they prolong the duration of the action potential and the refractory period. Also they slow down the spontaneous discharge frequency of automatic pacemakers by depressing the slope of diastolic depolarization. They shift the threshold towards zero or hyperpolarize the membrane potential. Although each agent has its own properties and will have thus a different function.
Tachycardia-induced cardiomyopathy (TIC) is a disease where prolonged tachycardia or arrhythmia causes an impairment of the myocardium, which can result in heart failure. People with TIC may have symptoms associated with heart failure and/or symptoms related to the tachycardia or arrhythmia. Though atrial fibrillation is the most common cause of TIC, several tachycardias and arrhythmias have been associated with the disease.
Ibutilide is a Class III antiarrhythmic agent that is indicated for acute cardioconversion of atrial fibrillation and atrial flutter of a recent onset to sinus rhythm. It exerts its antiarrhythmic effect by induction of slow inward sodium current, which prolongs action potential and refractory period (physiology) of myocardial cells. Because of its Class III antiarrhythmic activity, there should not be concomitant administration of Class Ia and Class III agents.
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.
Pilsicainide (INN) is an antiarrhythmic agent. It is marketed in Japan as サンリズム (Sunrythm). It was developed by Suntory Holdings Limited and first released in 1991. The JAN applies to the hydrochloride salt, pilsicainide hydrochloride.
Sodium channel blockers are drugs which impair the conduction of sodium ions (Na+) through sodium channels.
Atrial tachycardia is a type of heart rhythm problem in which the heart's electrical impulse comes from an ectopic pacemaker in the upper chambers (atria) of the heart, rather than from the sinoatrial node, the normal origin of the heart's electrical activity. As with any other form of tachycardia, the underlying mechanism can be either the rapid discharge of an abnormal focus, the presence of a ring of cardiac tissue that gives rise to a circle movement (reentry), or a triggered rapid rhythm due to other pathological circumstances.
Arrhythmia, also known as cardiac arrhythmia or heart arrhythmia, is a group of conditions in which the heartbeat is irregular, too fast, or too slow. The heart rate that is too fast – above 100 beats per minute in adults – is called tachycardia, and a 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 types of arrhythmia are not serious, some predispose a person to complications such as stroke or heart failure. Others may result in sudden death.
Celivarone is an experimental drug being tested for use in pharmacological antiarrhythmic therapy. Cardiac arrhythmia is any abnormality in the electrical activity of the heart. Arrhythmias range from mild to severe, sometimes causing symptoms like palpitations, dizziness, fainting, and even death. They can manifest as slow (bradycardia) or fast (tachycardia) heart rate, and may have a regular or irregular rhythm.