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Svt and Sinus tach

r9c
I was wondering is supra ventricular tachycardia and sinus tachycardia the same? was told by cardiologist that in svt the heart rate is much way higher than sinus tachycardia and svt does start and stop suddenly where sinus tachy gradually slows down on itself,just life after exercise etc.

Also,In sinus tachycardia, the heart beats normally, and blood flow is not changed. The electrical impulses controlling the heart beat fire correctly and automatically from the sino-atrial (SA) node, the heart's pacemaker.
Where in SVT,The excessive rate of beating keeps the chambers of the heart from adequately filling between contractions, and the body does not receive sufficient blood flow.In ECG they doctors and cardiologist also sometimes got confused with svt and sinus tach,is it true?
Best Answer
1124887 tn?1313754891
Hi,

There are a lot of supraventricular tachycardias, where sinus tachycardia is actually one of them.

Atrial tachycardia is somewhat similar to sinus tachycardia, except that the impulses origin somewhere else in the atria than the sinus node. It's really a line of PACs. Depending on the mechanism, atrial tachycardias can also "warm up" with gradually increasing heart rate (and decreasing).

Please be aware that sinus tachycardia also can get a lot higher than "normal max heart rate". This only determine how much the muscles and metabolic system can affect the heart to increase heart rate. You can easily have a sinus tachycardia of 240, if you have some disease that causes too high adrenaline levels, you have an anxiety out of another world, combined with low blood pressure, effort, etc. I read an article once where a 60 year old man with pulmonary embolism and shock had sinus tachycardia at rate 220 in the ER. That's far above his max heart rate.

Problem with rapid tachycardias are that the ventricles may not be able to fill completely. If you stand up too quickly after taking a hot bath, combined with some dehydration, you will probably have a heart rate of at least 150-170 for a moment. Your heart is giving gas without pumping so much blood (the blood is pooling up in the veins and your blood vessels are dilated). To be able to pump blood, the heart needs return of blood.

So-called re-entry tachycardias (AV nodal reentry tachycardia, AV reentry tachycardia, as Tom_h is familiar with, and atrial tachycardias caused by re-entry pathways) will start and stop abruptly. Like: BAM! initiated (often a PAC is the "sinner"), spinning... BAM! stopped.

Most SVT's are caused by re-entry, but in some cases, a temporary atrial abnormal "pacemaker" (which usually just fires off a PAC now and then) may get really annoyed and decide to fire PACs for a long time that are more rapid "overrules" the sinus node. This frequency may of course vary with it's "mood" and adrenaline stimulation.

Anyway, most tachycardias that start and stop gradually are sinus tachycardias.

Feel better!
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1124887 tn?1313754891
Hi, thanks a lot for selecting my answer as best answer :)

Well, you will get lightheaded and sinustachycardia if your blood pressure is low and the heart works hard to compensate. Circulation is always lagged compared to heart rate, so position changes, beginning of exercise, etc. can give a rapid increase in heart rate before enough blood returns to the heart so the beating can be efficient. This is a normal phenomenon.

If you faint, this reflex is too strong or out of sync and you should see a doctor. Otherwise, don't worry. Your heart is carefully examined and you're a healthy young man. Enjoy it! :)
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Avatar universal
r9c
thanks for the info guys,i actually had a 150bpm caught on my 24 hour holter but then the cardiologist said it was sinus tachycardia,not svt.Just worried that as we know that some SVT are similar to VT? thats is scary.Still i am not worried about that,its just those daily lightheaded accompany with tachycardia are scary.
Helpful - 0
1423357 tn?1511085442
I believe the cardiologist is correct on both counts. Although.... I've had sinus rhythms as high as 200 bpm during extreme physical output, while my SVT hovered in the 220-230 range, only 10-15% higher.

Regarding your second question, discounting the peak to peak frequency (rate), the waveform of sinus vs. SVT are completely different.  IOW, if you look at the waveform of someone going flat out on a treadmill vs. an individual sitting in a chair experiencing SVT.  They may have the same rate, but the waveforms will be different.
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Avatar universal
As to the doctors getting confused with svt and sinus tachy  on ekg--I dont think so.
All the EKGs I had (a LOT) they always had no problem telling the differnce. Mabye I am wrong, but I never heard of this.
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