Editing Cardiac arrest (section)

==== Inherited arrhythmia syndromes ====
Arrhythmias not due to structural heart disease account for 5 to 10% of sudden cardiac arrests.<ref>{{cite journal | vauthors = Chugh SS, Kelly KL, Titus JL | title = Sudden cardiac death with apparently normal heart | journal = Circulation | volume = 102 | issue = 6 | pages = 649–654 | date = August 2000 | pmid = 10931805 | doi = 10.1161/01.cir.102.6.649 | doi-access = free }}</ref><ref>{{cite journal | vauthors =  | title = Survivors of out-of-hospital cardiac arrest with apparently normal heart. Need for definition and standardized clinical evaluation. Consensus Statement of the Joint Steering Committees of the Unexplained Cardiac Arrest Registry of Europe and of the Idiopathic Ventricular Fibrillation Registry of the United States | journal = Circulation | volume = 95 | issue = 1 | pages = 265–272 | date = January 1997 | pmid = 8994445 | doi = 10.1161/01.cir.95.1.265 }}</ref><ref name="Drory-1991">{{cite journal | vauthors = Drory Y, Turetz Y, Hiss Y, Lev B, Fisman EZ, Pines A, Kramer MR | title = Sudden unexpected death in persons less than 40 years of age | journal = The American Journal of Cardiology | volume = 68 | issue = 13 | pages = 1388–1392 | date = November 1991 | pmid = 1951130 | doi = 10.1016/0002-9149(91)90251-f }}</ref> These are frequently caused by [[genetic disorder]]s.<ref name="Walls-2017" /> The genetic [[mutation]]s often affect specialized proteins known as [[ion channel]]s that conduct [[Ion|electrically charged particles]] across the [[cell membrane]], and this group of conditions is therefore often referred to as [[Channelopathy|channelopathies]]. Examples of these inherited arrhythmia syndromes include [[long QT syndrome]] (LQTS), [[Brugada syndrome]] (BrS), [[catecholaminergic polymorphic ventricular tachycardia]] (CPVT), and [[short QT syndrome]] (SQTS). Many are also associated with environmental or neurogenic triggers such as response to loud sounds that can initiate lethal arrhythmias.<ref name="Saunders-2015" />

LQTS, a condition often mentioned in young people's deaths, occurs in one of every 5000 to 7000 newborns and is estimated to be responsible for 3000 deaths annually compared to the approximately 300,000 cardiac arrests seen by emergency services.<ref name="American Heart Association">{{cite web | url = http://www.americanheart.org/presenter.jhtml?identifier=4741 | title = Sudden Cardiac Death | archive-url = https://web.archive.org/web/20100325174959/http://www.americanheart.org/presenter.jhtml?identifier=4741| archive-date=2010-03-25 | publisher = American Heart Association }}</ref> These conditions are a fraction of the overall deaths related to cardiac arrest but represent conditions that may be detected prior to arrest and may be treatable. The symptomatic expression of LQTS is quite broad and more often presents with [[Syncope (medicine)|syncope]] rather than cardiac arrest. The risk of cardiac arrest is still present, and people with family histories of sudden cardiac arrests should be screened for LQTS and other treatable causes of lethal arrhythmia. Higher levels of risk for cardiac arrest are associated with female sex, more significant QT prolongation, history of unexplained syncope (fainting spells), or premature sudden cardiac death.<ref name="Saunders-2015" /> Additionally, individuals with LQTS should avoid certain medications that carry the risk of increasing the severity of this conduction abnormality, such as certain anti-arrhythmics, anti-depressants, and [[Quinolone antibiotic|quinolone]] or [[macrolide]] antibiotics.<ref>{{cite journal | vauthors = Fazio G, Vernuccio F, Grutta G, Re GL | title = Drugs to be avoided in patients with long QT syndrome: Focus on the anaesthesiological management | journal = World Journal of Cardiology | volume = 5 | issue = 4 | pages = 87–93 | date = April 2013 | pmid = 23675554 | pmc = 3653016 | doi = 10.4330/wjc.v5.i4.87 | doi-access = free }}</ref>

Although it is not recognized as an inherited condition, [[Wolff–Parkinson–White syndrome]] in which an accessory conduction pathway bypassing the atrioventricular node is present and can cause abnormal conduction patterns leading to supraventricular tachycardia, pre-excited atrial fibrillation, and cardiac arrest.<ref name="Podrid-2016" />  [[Ebstein's anomaly]] has an increased risk of accessory pathways as well.