Introduction Diaphragmatic myoclonus, also called diaphragmatic flutter, is a disorder associated with repetitive, involuntary contractions of the diaphragm and other inspiratory muscles. This entity remains rare with few reported cases. Its pathogenesis is unknown. Myoclonus, in general, is sensitive to external stimuli. It can be induced, for example, by sudden noise, light, visual threat, muscle contraction, or pain. Previous reports of diaphragmatic myoclonus have not identified specific triggers. We report here a case of diaphragmatic myoclonus provoked by pacemaker mode switching.