Hello! Thank you for asking oh HCM! I am glad to confirm you that Advil does not trigger any known arrhythmia facing current medical data as far. If your mom experience heart palpitations, probably this is caused by the primary disorder that generates pain, or something else. If palpitations persist and become disturbing, then you need to talk with your doctor (internist or cardiologist) for a comprehensive medical check up, to investigate her cardiac status, to identify any possible arrhythmia, or heart failure, or exclude any triggering factors, like anemia, thyroid dysfunction, etc. If Advil treatment aggravates those palpitations, then your mom should stop taking the drug, and discuss with the prescribing doctor about a safer alternative. Hope to have been helpful. Greetings! Dr. Iliri