: 833  Additionally, individuals with LQTS should avoid certain medications that carry the risk of increasing the severity of this conduction abnormality such as certain anti-arrhythmic, anti-depressant, and quinolone or macrolide antibiotics. Non-cardiac causes
Non-cardiac causes accounts for 15 to 25% of cardiac arrests. The most common non-cardiac causes are trauma, major bleeding (gastrointestinal bleeding, aortic rupture, or intracranial hemorrhage), hypovolemic shock, overdose, drowning, and pulmonary embolism. Cardiac arrest can also be caused by poisoning like the stings of certain jellyfish, or through electrocution, like lightning. Reversible causes
Other non-cardiac causes of cardiac arrest may result from temporary disturbances in the bodies homeostasis. This may be the result from changes in electrolyte ratios, oxygen saturation, or alterations of other ions influencing the bodys pH. Mnemonic for reversible causes
"Hs and Ts" is the name for a mnemonic used to remember the treatable or reversible causes of cardiac arrest. Note: This mnemonic includes causes of cardiac and non-cardiac origin, but all are reversible with appropriate and time-sensitive treatment.
Cardiopulmonary resuscitation
Early cardiopulmonary resuscitation (CPR) is essential to surviving cardiac arrest with good neurological function. It is recommended that it be started as soon as possible with minimal interruptions once begun. The components of CPR that make the greatest difference in survival are chest compressions and defibrillating shockable rhythms. After defibrillation, chest compressions should be continued for two minutes before a rhythm check is again done. This is based on a compression rate of 100-120 compressions per minute, a compression depth of 5–6 centimeters into the chest, full chest recoil, and a ventilation rate of 10 breath ventilations per minute. Correctly performed bystander CPR has been shown to increase survival; however, it is performed in less than 30% of out of hospital arrests as of 2007. If high-quality CPR has not resulted in return of spontaneous circulation and the persons heart rhythm is in asystole, discontinuing CPR and pronouncing the persons death is reasonable after 20 minutes. Exceptions to this include certain cases with hypothermia or who have drowned. Some of these cases should have longer and more sustained CPR until they are nearly normothermic. Longer durations of CPR may be reasonable in those who have cardiac arrest while in hospital. Bystander CPR, by the lay public, before the arrival of EMS also improves outcomes.Either a bag valve mask or an advanced airway may be used to help with breathing particularly since vomiting and regurgitation are common, particularly in out-of-hospital cardiac arrest (OHCA).