Re-entrant Supraventricular Tachycardia (RSVT)

In 1996 Bobby had a heart condition that caused his heart to beat very fast. He was succesfully treated for the problem. Many people have asked about this, so we are posting this information to help answer your questions.

The following information was generously provided by physiologist Michael Lepp:

Bobby’s condition was determined to be a general condition called Re-entrant Supraventricular Tachycardia (RSVT). It can have many causes, but in Bobby’s case it was probably a congenital defect and/or caused by a mild virus when he was young.

In most cases, it is a benign condition where the normal heart conduction system (70-80 bpm at rest) short circuits and suddenly accelerates to 180-250 bpm (at rest) and sometimes even a bit higher during exercise. It is less serious than ventricular tachycardia (VT) or cardiac arrest because this rhythm is supraventricular, or above the ventricles. The reason for this is because the ventricles during RSVT fill normally and blood is still completely ejected into the body and perfusion takes place. When VT occurs, the ventricles try to eject blood before the fill from the atria, this results in little or no blood ejected into the circulation.

Although, RSVT is less serious than VT, effective cardiac output is reduced. Subjects may become lightheaded, and certainly optimal physical activity can’t occur. The condition can occur at any time, at rest or during activity and can last from a few seconds or hours. In Bobby’s case, it often occurred during high intensity activity, with the “renegade cardiac cell” excited by the adrenaline of the activity. When he stopped the activity, it would often stop, but this was impractical during bicycle racing.

Because there can be many causes of RSVT, the conditions such as major heart disease should be considered first. Treating these should cause the arrhythmia to decrease. (ie this rhythm may occur following a heart attack). In most cases such as Bobby’s and many young people, the condition is not related to major heart disease, and is benign in most cases. However, if this arrhythmia occurs frequently and causes a decrease in quality of life, it should be treated. Untreated, frequent episodes over a period of time can lead to heart failure.

There are many treatment options, and prior to a few years ago medications were used to either decrease the frequency of episodes, or decrease the rate response. Medical therapy is often fine for persons with normal sedentary occupations, but not optimal for athletes because they often blunt heart rates too much. A more recent option and one that Bobby had was Radiofrequency Ablation.

Radiofrequency Ablation can totally eliminate the renegade cell causing the arrhythmia and therefore the arrhythmia itself. It is generally not as serious as surgery, but involves making a small anesthetized incision in the groin and feeding a catheter in a vessel up to the heart. The cardiologist will then attempt to initiate the arrhythmia with drugs, and by using a special catheter he can “electrically map” the heart. It is through this technique that the cardiologist can actually see the renegade cell. Afterwards, using a type of radio wave the renegade cell is “burned” or eliminated. Hopefully, the re-entrant circuit will now be removed. This marginally invasive procedure often only requires 1-2 days in the hospital. In rare instances we are unable to successfully initiate the arrhythmia and can’t ablate the renegade cell.

It should be understood that this problem should not be self-diagnosed. If someone is having frequent heart rhythm problems, they should immediately contact their personal physician, especially if they are having sustained heart rate increases or light headedness.

People may contact me at the link below with any questions. I or my affiliates may have colleagues for possible referral around the US that can help you. The link below also contains some useful information about cardiac arrhythmias and is graciously provided by Wake Forest University Medical Center.

J. Michael Lepp, M.S.
Exercise Physiologist

ZoneOne Sport Science

Integrative Cardiology

Click here to email J. Michael Lepp

For educational material on arrhythmias: Wake Forest Baptist Medical Center