Dr. Roach: Frequent PVCs have reader perplexed
Dear Dr. Roach: I am a 75-year-old man who recently experienced three episodes of lightheadedness. After testing, my cardiologist determined that these were not likely to be cardiac in origin. My concern is with the result of my 24-hour Holter monitor, which showed a little more than 1,000 isolated PVCs in 24 hours. I have been told that this is either “dire” or “not an issue.” I would appreciate your comments on the issue and any discussion of treatment for frequent PVCs.
Dear J.G.: Normally in the heart, the electrical impulse starts at the sinoatrial node, often called the pacemaker of the heart. The impulse proceeds down clearly defined pathways (think of them as wires) to the atrioventricular node, where it waits for the mechanics of the heart to catch up with the electrical system. The electrical impulse travels down the bundle of His to the Purkinje fibers, which stimulate the ventricle.
Occasionally, in everyone, an electrical impulse comes from a different part of the heart before the normal SA impulse. If it comes from the atria, it is called a premature atrial contraction; and if it’s from the much larger ventricles, a premature ventricular contraction. These are distinguishable on an EKG. A PAC is early and narrow (since the impulse will go through the AV node), while a PVC is early and wide (since it doesn’t, and must travel cell to cell).
My opinion is that frequent PVCs at your level is somewhere between “not an issue” and “dire.” One study showed that people who had no known heart disease but more than 30 PVCs an hour (720 in 24 hours) have an increased risk of heart disease over people with fewer than 30 per hour. The overall increase in risk is not large in absolute terms, however.
Although there is treatment that can reduce PVCs, it’s not clear that this reduces the risk of heart disease, and some treatments actually increase mortality risk. I recommend treatment for frequent PVCs only if there are very bothersome symptoms that are clearly related to the PVCs, or in the very infrequent event of someone with so many PVCs that the fast heart rate damages the heart.
Dear Dr. Roach: I read with interest your response to the patient with smoldering multiple myeloma. Seven years ago, I also was diagnosed with smoldering myeloma and was told exactly what the patient who wrote in was told. I went to Mayo Clinic in Rochester, Minnesota, where they had a study using dexamethasone once a week with a daily injection of anakinra. I am having no symptoms, have no bone lesions and all my blood work is normal.
Dear C.S.: Thank you for writing in. I looked up the study and found, indeed, a very favorable preliminary (phase 2) trial. This looks to be a significant advance in treatment of smoldering myeloma.
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