Heart & Cardiology/SVT


QUESTION: I have had SVT for a few years and I take 50mg of Atenolol to keep it under control.  I accidentally let my prescription run out for about 3 days and I have had a few episodes where my heart was racing over 200 BPM and I felt as if I was going to pass out.  I have since restarted my medicine a couple of days ago, but I am still having some episodes.  These last around 2 minutes and may occur up to a couple of times an hour.  Do I need to seek medical attention now, or should I just wait it out?  Thank you.  -Robert

ANSWER: Hi Robert,

SVT is generally not considered dangerous or life threatening in the majority of people unless you have underlying heart disease such as coronary artery disease, or heart failure. However, such as in your case during SVT the heart goes up to >200 beats per minute and do there are typically associated symptoms such as sensation of shortness of breath, chest symptoms and dizziness. (Of course anyone experiencing new symptoms that they are worried about should go to the ER to be evaluated)

The reason you have an SVT is that there is a slight abnormality in the electrical circuit that governs your heart. This is very common, you would be amazed how many people have it. This abnormality basically leads to a kind of short circuit that gives you the SVT.

You have a few options that you should go and discuss with your Dr. 1) Continue the current medicine or a similar medicine to it but increase the dose 2) try a different class of medicines that acts in a different way to prevent the SVT , called anti-arrhythmic drugs (wont get in to it too much here!) or 3) have a procedure to get rid of it. Also you should learn certain simple techniques like the valsalva maneouvre that can break the tachycardia for times it comes up, or you dont have medications.

More and more nowadays we are moving towards the third option, a procedure. Not for any other reason than in the right hands it is very safe, and you can expect >90% cure of the SVT, and importantly it will allow you to not have to take medications for the rest of your life. Some cardiologists may want you to wear a monitor to document the episodes and catch a tracing.

If I were you I would 1) if at anytime you are worried enough to want to go to the ER or seek medical advice, for example the tachycardia is lasting a long time or the symptoms are strong, just go. If the tachycardia is ongoing it would allow you to catch a tracing of it. 2) Go see a cardiologist to discuss the options discussed above and to get you feeling better, an SVT, if thats what you have, is very treatable.

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Hope that was helpful

---------- FOLLOW-UP ----------

QUESTION: Thanks, that was very helpful.  I was reading about procedures for SVT and I came across ablation in atrial fibrillation.  Is this what you are talking about?  Could I have atrial fibrillation?

Hi Robert, read here  http://blog.myheart.net and http://blog.myheart.net/2014/06/29/afib-with-rvr-when-the-heart-races-out-of-con for more information regarding atrial fibrillation.

Although technically atrial fibrillation is a kind of SVT, its unlikely you have it if you were told you specifically had SVT. If you had atrial fibrillation then you would have been told that.

The ablation procedure for atrial fibrillation is very different from the one for common SVT. Whereas ablation for common SVT has almost a >95% success rate and is considered a first line treatment, the procedure for atrial fibrillation has a success rate in the 50's-70's% (sometimes higher)  depending on who you ask and is generally used for those in whom medicines did not work.

Hope that was helpful

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Mustafa Ahmed MD


Cardiology, Interventional Cardiology, Cardiac Surgery, Hypertension, Pulmonary Embolism, Structural and Valve Disease


Board Certification Internal Medicine and Cardiology Interventional and Structural Cardiology


Multiple Publications In High Quality Peer Reviewed Journals. Internationally Recognized.

MD from The Royal Victoria University of Manchester, England Medicine, Cardiology, Interventional Cardiology, Research Training - University of Alabama

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