Supraventricular Tachycardia (SVT) - Can I get an explanation?

  1. Can one of you lovely ladies (not to make assumptions ) break that down for me Barney Style? I've looked it up in all of my books, but none of them seem to give a real thorough explanation.

    About all I've been able to glean so far is that the SA node is misfiring and that it's generally a bad thing.
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  2. 5 Comments

  3. by   suzanne4
    If you send me your e-mail address I will send you the handout that I give to my students. It will give you a full explanation that is easy to understand.
  4. by   RNKPCE
    It is a tachycardia who impulse is generated above the ventricles but does not start in the sinus node.
  5. by   RNCENCCRNNREMTP
    Quote from ClimbingNurse
    Can one of you lovely ladies (not to make assumptions ) break that down for me Barney Style? I've looked it up in all of my books, but none of them seem to give a real thorough explanation.

    About all I've been able to glean so far is that the SA node is misfiring and that it's generally a bad thing.
    Supraventricular tachycardia (SVT) is a broad term that refers to any tachycardic rhythm that has its origins above the ventricles. Technically, sinus tachycardia could be called SVT but realistically it refers to a re-entry type mechanism either involving the AV node or the AV node and some abnormal connection between the atria and the ventricles. To make it short, a continuously cycling depolarization wave re-enters the ventricles from the atria 9through one of the 2 mentioned pathways) and every time it re-enters the ventricles it causes them to depolarize, often at rates of 200-300/minute.

    Adenosine is a drug used to "break" this cycle and allow a sinus rhythm to re-emerge.

    Short but sweet because my wife needs my help right now. :angryfire
  6. by   paralegalrn
    It is a rhythm that occurs when there is a fast, strong stimulus from an ectopic focus above the ventricles and belw the SA node and the heart conducts every beat. rate 150-250 bpm. Example: It can result from inadequate refilling time, similar to squeezing a sponge fast under water and never allowing it to open or fill completely. This can result in low blood pressure and a person's heart cannot sustain this thythm for long because the muscle itself gets tired. This comes from a book entitled "Flip and See ECG" very, very simple to understand things using this book. I hope this helps. I am Linda, Cardiac Nurse. To make even more visual think of the water as your SA node, the sponge as the inside of the ventricles and your hand is the ectopic focus causing the water not to communicate with the sponge, since the ectopic focus is below the SA node you doing your job by firing and because you do not get a answer from the ventricles you start firing a faster response but no matter how hard you work that hand does not let the ventricles fill up instead it just squeezes harder so after awhile your hand gets tired.
    Last edit by paralegalrn on Apr 24, '04 : Reason: forgot something
  7. by   ClimbingNurse
    Awesome! Thanks gals and guys!

    keith

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