Pulsus bigeminus
Pulsus bigeminus is a cardiovascular phenomenon characterized by groups of two heartbeats close together followed by a longer pause. The second pulse is weaker than the first. It is caused by premature contractions, usually of the ventricles, after every other beat, so called extrasystoles. It can be a sign of hypertrophic obstructive cardiomyopathy or of many other types of heart disease. It can also be an innocent and passing phenomenon. Digitalis toxicity can cause this type of phenomenon.