What Makes a Heart Go Offbeat?

Usually irregular heartbeats occur because areas of the heart are beating more rapidly than normal, and sometimes a palpitation is more of a short-circuit in the heart's electrical system, explains J. Michael Mangrum, M.D., director of University of Virginia Health System's Atrial Fibrillation Center. In the case of atrial fibrillation, mixed electrical signals in the upper chambers of the heart cause heart muscle there to quiver, or fibrillate, rather than contracting in an organized way. Often, palpitations may be linked to: 

  • extFind doctors who specialize in heart rhythm conditionsended periods of stress
  • fear, anxiety or panic attacks
  • use of caffeine or other stimulants, including antihistamines and over-the-counter diet aids
  • alcohol intake, especially binge drinking 
  • physical activity, particularly when strenuous or competitive
  • Atrial Fibrillationan overactive thyroid


Sometimes, atrial fibrillation results from changes to the tissue structure of the heart's upper chamber (atrium). These changes may be caused by an existing health condition such as high blood pressure, coronary artery disease, heart failure, damage to a heart valve, chronic lung disease, thyroid disorders, or by excessive alcohol intake. In this case, treating the underlying condition may be the first line of defense.