# Sinus Tachycardia --- **Sinus tachycardia** is an [[arrhythmia]] where the heartbeat is in a normal rhythm but abnormally fast. Typically a heartrate is considered tachycardic if it's over 100 BPM, but unless the patient is symptomatic we don't try to treat it necessarily. EXAMPLE TACHY RYTHMN >[!abstract]- Normal sinus rhythm for reference >![[normal sinus.png]] ## Causes There are a variety of causes of tachycardia: - stress - medications/substances - caffeiene, nicotene, albuteral, amphetamines - autonomic dysfunction POTS - for example, when we go from lying to sitting or standing, our body release hormonies like epinepherine and norepinephrine, and this happens really fast. we probably don't even notice when this is happening. - [[POTS]] - postorail orthostatic tachycardic syndrome - Laying flat is fine, but if one stands they become tachycardic - this really sucks to have, it can be debilitating - can happen with any virus - you see this a lot after [[COVID]] - mismatch between SNS & PNS activity - this is not really understood and pretty rare ## Treatment As there are a wide range of causes of tachycardia, there are a wide range of treatements. The most simple is trying to calm down with breathing or relaxation techniques. A [[vagus nerve|vagal manouver]] can even help. You can also do *synchronized* [[cardioversion]] (but I think that's only for unstable tachycardia). There's also something about a a cardiac artery massage, but I'm not sure what that's all about, I don't think it's common. Medications - [[beta blockers]] - [[calcium channel blockers]] - (adenosine is not used for this one, only for supraventricular tachycardias) ___