Heart rate variability (HRV) is the physiological phenomenon of variation in the time interval between heartbeats.It is measured by the variation in the beat-to-beat interval.Other terms used include: cycle length variability, RR variability (where R is a point corresponding to the peak of the QRS complex of the ECG wave; and RR is the interval between successive Rs), and heart period variability.ariation in the beat-to-beat interval is a physiological phenomenon. The SA node receives several different inputs and the instantaneous heart rate or RR interval and its variation are the results of these inputs. The main inputs are the sympathetic and the parasympathetic nervous system (PSNS) and humoral factors.
A:Pell grant is a federal grant that is given on need basis to the financially deserving students. Pell grant application process is a simple one that begins with Free Application for Federal Student Aid (FAFSA) form that has to be filled. The form is available online.
Pell Grant Recipients. 1  A Pell Grant applicant must complete the entire process before the Pell Grant Program deadline in September or 120 days after the last day of the studentâs enrollment which ever is earlier. 2  If the process is not complete the student is not eligible for Pell for that award year.