<unk>   is an exaggeration of the normal variation in the pulse and drop of systolic blood pressure during the inspiratory phase of respiration, in which the pulse becomes weaker as one inhales and stronger as one exhales. It is a sign that is indicative of several conditions including cardiac tamponade and lung diseases (e.g. asthma, COPD).
Pulsus paradoxus
Pulsus alternans
Pulsus parvus et tardus
Collapsing pulse
Pulsus bigeminus
Muffled heart sounds
Wide pulse pressure
Irregular pulse