Supraventricular Tachycardia
Supraventricular Tachycardia (SVT)
SVT is a broad term for a number of tachyarrhythmias that originate above the ventricular electrical conduction system (purkinje fibers).
Classic Paroxysmal SVT has a narrow QRS complex & has a very regular rhythm. Inverted P waves are sometimes seen after the QRS complex. These are called retrograde p waves
The heart fills during diastole, and diastole is normally 2/3 the cardiac cycle. A rapid heart rate will significantly reduce the time which the ventricles have to fill. The reduced filling time results in a smaller amount of blood ejected from the heart during systole. The end result is a drop in cardiac output & hypotension.
With the drop in cardiac output, a patient may experience the following symptoms. These symptoms occur more frequently with a heart rate >150 beats per minute:
- Shortness of air (S)
- Palpitation feeling in chest (S)
- Ongoing chest pain (U)
- Dizziness (S)
- Rapid breathing (S)
- Loss of consciousness (U)
- Numbness of body parts (S)
The pathway of choice for SVT in the tachycardia algorithm is based on whether the patient is stable or unstable. The symptoms listed above that would indicate the patient is unstable are noted with the letter (U). Stable but serious symptoms are indicated with the letter (S).
Unstable patients with SVT and a pulse are always treated with cardioversion
Below is a short video which will help you quickly identify supraventricular tachycardia on a monitor.
Please allow several seconds for the video to load.
The rhythm shown in the above EKG is a classical A-V nodal re-entrant tachycardia (AVNRT)
excellent site good interpretations and explanations
I am definitely impressed with this site and teaching.
what about the stable SVT?
Stable SVT would be a supraventricular tachycardia in which the patient is having no symptoms that classified as unstable (hypotension SBP<90, changes in level of consciousness, chest pain). For instance, some time ago I took care of a 50 something female with SVT (HR 160's). Here only symptom was having the feeling that her heart was racing. No chest pain, no hypotension, etc. She was stable. I hope this makes sense. Kind Regards, Jeff
I am one of those 50-something females who have AV nodal re-entrant tachycardia with no other symptoms. Only tachycardia …and a feeling like a 10# weight is whirling about in my chest. This started in August for me. I am excited to be scheduled for an ablation on the 16th of this month. As a B.S.N, appreciate the site also!
I really like the different examples of how it may look….thank you
This is great to be able to reivew and keep up on the acls.
seriously,this is good teaching,you can review all this on your own time.