Dear Suzy,
I’m a little confused by the information that you are giving me. You say that his event monitor demonstrated SVPB’s, which I am taking to be supraventricular premature beats, also known as premature atrial contractions, or PAC’s. However, you say that he had premature ventricular contractions, or PVC’s, with exercise. For our other readers, both of these are abnormal heart rhythms. PAC’s are early beats that initiate in the atria, or the upper chambers of the heart. PVC’s originate in the lower chambers, or the ventricles. Bigeminy is a term that is used when a the rhythm is an alternating rhythm of normal followed by an early beat; in this case, the early beat sounds like it is a PVC. Typically, exercise-induced (or worsened) early beats, also known as ectopy) is not considered to be a normal finding. However, I also cannot tell from what you are saying if his symptoms are worse, his PVC’s are worse, or both, and if they correlate with each other. Overall, exercise-associated ectopy can be caused by structural heart defects, infections, medications, electrolyte abnormalities, genetic abnormalities of electrolyte channels in the heart, and other reasons. Without much more information, I cannot tell the reason for your son’s PAC’s and PVC’s specifically. Therefore, I do recommend that this be evaluated more completely. If it turns out that his PVC’s are, in fact, increasing with exercise, you may also need to consider taking your son to a pediatric electrophysiologist, a pediatric cardiologist that specializes in the electrical system of the heart.
Thank you for answering my post.I too am confused by the different readings on the holter monitor and stress test. The stress test definitely showed pvc's which the holter did not show at the time. I guess I will go ahead and see about one of the specialists you mentioned.