Search results
Results from the WOW.Com Content Network
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited genetic disorder that predisposes those affected to potentially life-threatening abnormal heart rhythms or arrhythmias. The arrhythmias seen in CPVT typically occur during exercise or at times of emotional stress, and classically take the form of bidirectional ...
Early afterdepolarizations can result in torsades de pointes, tachycardia, and other arrhythmias. [3] EADs can be triggered by hypokalemia and drugs that prolong the QT interval, including class Ia and III antiarrhythmic agents, as well as catecholamines. [1] Afterhyperpolarizations can also occur in cortical pyramidal neurons.
Catecholamines are produced mainly by the chromaffin cells of the adrenal medulla and the postganglionic fibers of the sympathetic nervous system. Dopamine, which acts as a neurotransmitter in the central nervous system, is largely produced in neuronal cell bodies in two areas of the brainstem: the ventral tegmental area and the substantia nigra, the latter of which contains neuromelanin ...
Examples of these inherited arrhythmia syndromes include Long QT syndrome (LQTS), Brugada Syndrome, Catecholaminergic polymorphic ventricular tachycardia, and Short QT syndrome. Many are also associated with environmental or neurogenic triggers such as response to loud sounds that can initiate lethal arrhythmias.
Catecholaminergic means "related to catecholamines". The catecholamine neurotransmitters include dopamine , epinephrine (adrenaline), and norepinephrine (noradrenaline). A catecholaminergic agent (or drug ) is a chemical which functions to directly modulate the catecholamine systems in the body or brain.
The mechanisms of sympathomimetic drugs can be direct-acting (direct interaction between drug and receptor), such as α-adrenergic agonists, β-adrenergic agonists, and dopaminergic agonists; or indirect-acting (interaction not between drug and receptor), such as MAOIs, COMT inhibitors, release stimulants, and reuptake inhibitors that increase the levels of endogenous catecholamines.
The abnormal heart rhythms seen in those with Brugada syndrome are typically dangerous arrhythmias such as ventricular fibrillation or polymorphic ventricular tachycardia, but those with BrS are also more likely to experience rapid heart rates due to less dangerous arrhythmias such as AV nodal re-entrant tachycardia [30] and abnormally slow ...
Catecholaminergic cell groups refers to collections of neurons in the central nervous system that have been demonstrated by histochemical fluorescence to contain one of the neurotransmitters dopamine or norepinephrine. Thus, it represents the combination of dopaminergic cell groups and noradrenergic cell groups. [1]