A recent retrospective study published in the Journal of Cardiovascular Electrophysiology found that atrial fibrillation (AF) occurred for the first time in 16 of 30 patients (53%) of patients with implantable devices being followed at the center conducting the study.

Of the patients experiencing AF for the first time, 14 of 16 (88%) of the patients were not aware of having experienced any clinical symptoms.  As patients age, AF appears to be a common consequence of HCM.  Patients may be caught unaware and unprepared, so monitoring is especially important.