• A rapid or irregular heartbeat that a person can feel.
  NCI Dictionary of Cancer Terms
  U.S. National Cancer Institute, 2021
• An unpleasant sensation of irregular and/or forceful beating of the heart.
  NCI
  U.S. National Cancer Institute, 2021
• Sensation that the heart is beating rapidly or irregularly.
  Harvard Dictionary of Health Terms
  Harvard Medical Publishing, 2011
• The sensation of an irregular and/or forceful heart beat.
  NICHD Pediatric Terminology
  U.S. National Cancer Institute, 2021
• A clinical historical feature in which there is the sensation of the heart beating abnormally in rate, rhythm, or force.
  ACC/AHA Clinical Data Terminology
  American College of Cardiology and American Heart Association , 2020
• A sensation that the heart is pounding or racing, which is a non-specific sign but may be a manifestation of arrhythmia.
  Human Phenotype Ontology (HPO)
  The Human Phenotype Ontology Project, 2025
• A disorder characterized by an unpleasant sensation of irregular and/or forceful beating of the heart.
  Common Terminology Criteria for Adverse Events
  U.S. National Institutes of Health, 2021
• Palpitations are the perception of cardiac activity. They are often described as a fluttering, racing, or skipping sensation. They are common; some patients find them unpleasant and alarming. Palpitations can occur in the absence of heart disease or can result from life-threatening heart disorders. The key to diagnosis and treatment is...
  Merck Manuals
  Merck & Co., Inc., 2025