PACs or PVCs
Extra heartbeats that come from outside the heart
's normal electrical system can cause a sensation of skipped or strong heartbeats.
These can come from the top chambers of the heart (atrium, premature atrial contractions, pacs) or the bottom chambers (ventricles, premature ventricular contractions, pvcs). Wearing a heart monitor can help determine if this is happening, it is usually not serious.