“Heartbeats”

Most likely what he meant was that you were having premature extra beats. These can come from either of the top chambers, in which case they are called atrial premature beats or the lower pumping chamber, which is called a ventricular premature be in general, these are relatively benign, and not of concern. If you need further clarification about the “too many beats“ I would ask your doctor. .

Too many heart beats sounds like premature contractions coming from upper chambers ( premature atrial contractions) or lower chamber ( premature ventricular contractions). In themselves these are not a serious issue. Stimulants. Sinus meds, coffeine, electrolytes abnormalities can cause them. Anything that increases adrenaline in the body. Also electrolyte abnormalities. This can be related to an underlying problem with the heart muscle (cardiomyopathy), scars (previous MI / heart attacks) , or ischemic heart disease ( plaque blocking coronary blood flow). If you have those underlying conditions, see your cardiologist. The treatment can be watch and wait because they come and go spontaneously. Or medication to slow down the heart ( beta blockers) or true antiarrhythmic medications if they are frequent and symptomatic. The vast majority of the time this resolves with treatment and time. Everyone has them but not everyone feels them ( extra forceful beats if it PvC) . Of course this is a presumption on my part because the sentence the physician told you is very nonspecific. Perhaps he meant an underlying arrhythmia like atrial fibrillation or atrial flutter. I doubt that because he would have treated those conditions. The other possibility is gallop beats or abnormal heart sounds. These are not true extra beats but extra sounds blood makes when it fill a diseased abnormal left ventricle. Again, this would have warranted a much different discussion, work up and treatment. My best guess would be extra beats and you should be fine. As for the treatment of your cancer, the regimen used for colon cancer tends to not result in damage to the heart. In the old days high doses of anthracyclines ( doxorubicin and daunorubicin) for breast cancer and lymphomas, caused dilated weakened ventricles and heart failure. Oncologist are very careful in todays chemo regimens, and I have not seen a chemo induced , new cardiomyopathy in recent memory. The heart is monitored throughout if and when the cancer agent presents cardiac risk. This would have occurred before 2 years and you would have heart failure signs and symptoms ( shortness of breath, fluid build up). Radiation can also damage the heart if its in the x - ray field , which shouldnt happen with colon cancer. Best of the doctors vague explanation, I would be surprised if this is anything serious