Nonsustained

Nonsustained is an adjective used to describe something that occurs briefly and does not persist. It is formed from the prefix non- plus sustained, and is used across disciplines to contrast with phenomena that are sustained or lasting.

In clinical contexts, the term frequently appears in cardiology with nonsustained ventricular tachycardia (NSVT) or nonsustained arrhythmias. These are episodes that last briefly and terminate on their own, often defined as three or more consecutive heartbeats at a rapid rate lasting less than 30 seconds. The exact thresholds can vary by guidelines. Nonsustained arrhythmias may be incidental findings or signal underlying heart disease; clinical implications depend on the pattern, patient risk, and accompanying symptoms.

In engineering and physics, nonsustained oscillations refer to vibrations or waves that decay over time due to damping, as opposed to sustained oscillations that persist. Nonsustained events can arise from transient disturbances, control system responses, or structural damping.

In general language, nonsustained describes anything temporary or short-lived, such as nonsustained applause, weather effects, or experimental results that fade quickly. The term emphasizes the lack of continuation rather than the absence of initial occurrence.

See also: sustained, transient, transient phenomenon.