In newborns, what is an abnormal fine tremor felt on palpation known as?

The term for an abnormal fine tremor that can be felt on palpation in newborns is referred to as a "thrill." A thrill is characterized as a palpable vibration that often accompanies abnormal blood flow, typically associated with significant cardiovascular issues or vascular malformations. In the context of a newborn, the presence of a thrill can indicate underlying pathologies that may necessitate further evaluation by healthcare professionals to ensure appropriate management and care.

In contrast, a bruit refers to an abnormal sound detected through auscultation and suggests turbulent blood flow, usually not something that is palpated. An arrhythmia denotes irregularities in the heart rhythm, while a murmur is a sound made by turbulent blood flow typically heard with a stethoscope rather than felt. Each of these terms describes distinct physiological phenomena and underscores the importance of correct terminology in assessing newborns.