Latency in Communication is measured data also have Watch and Warning of Flights through NOTAM

Latency is a time interval between the stimulation and response, or, from a more general point of view, as a time delay between the cause and the effect of some physical change in the system being observed. Latency is physically a consequence of the limited velocity with which any physical interaction can propagate. This velocity is always lower than or equal to the speed of light. Therefore every physical system that has spatial dimensions different from zero will experience some sort of latency, regardless of the nature of stimulation that it has been exposed to.

The precise definition of latency depends on the system being observed and the nature of stimulation. In communications, the lower limit of latency is determined by the medium being used for communications. In reliable two-way communication systems, latency limits the maximum rate that information can be transmitted, as there is often a limit on the amount of information that is "in-flight" at any one moment. In the field of human–machine interaction, perceptible latency has a strong effect on user satisfaction and usability.
With The advance of Jet Flight Latency becomes a problem with Pacemaker and even the Heart beat above 10,000 feet elevation. The problem again is not so much the Heart or Pacemaker but how data was gathered into a Fluid Mechanics to Engineering and Fluid Blood Motion within Fight itself above 10,000 feet is the current warning of Air Flight Travel of patient and even The Heart Itself in Fluid Mechanics of Flight and The Human Traveler.

Pacemaker syndrome is a disease that represents the clinical consequences of suboptimal atrioventricular (AV)synchrony or AV dyssynchrony, regardless of the pacing mode, after pacemaker implantation. It is aniatrogenic disease—an adverse effect resulting from medical treatment—that is often underdiagnosed. In general, the symptoms of the syndrome are a combination of decreased cardiac output, loss of atrial contribution toventricular filling, loss of total peripheral resistance response, and nonphysiologic pressure waves.

Individuals with a low heart rate prior to pacemaker implantation are more at risk of developing pacemaker syndrome. Normally the first chamber of the heart (atrium) contracts as the second chamber (ventricle) is relaxed, allowing the ventricle to fill before it contracts and pumps blood out of the heart. When the timing between the two chambers goes out of synchronization, less blood is delivered on each beat. Patients who develop pacemaker syndrome may require adjustment of the pacemaker, or fitting of another lead to better coordinate the timing of atrial and ventricular contraction.