Abstract:
Tydens die normale funksionering van die hart fluktueer die intervalle tussen opeenvolgende hartslae (R-R-intervalle) rondom 'n gemiddelde waarde. Hierdie fluktuering staan bekend as harttempovariasie (HTV). Verskillende metodes word gebruik om HTV te bepaal maar dit is nie bekend tot watter mate daar ooreenstemming is tussen die resultate van die verskillende metodes waarmee HTV ondersoek word nie. In hierdie studie word HTV, soos bepaal vanaf die EKG, vergelyk met resultate soos verkry met behulp van tyddomeinanalise, frekwensiedomeinanalise, Poincaré-grafieke en fraktaalanalise. Die resultate van hierdie studie toon dat, in individue met laer HTV, met tyddomeinanalise, frekwensiedomeinanalise, Poincaré en Alfa 1 van fraktale analise dieselfde tendense in HTV waardes verkry word as deur direkte meting van die V6- variasie op die EKG. Die resultate toon egter verder dat tyddomeinanalise, frekwensiedomeinanalise, Poincaré en fraktale analise minder sensitief is by hoër HTV waardes.
Oscillation around a mean value is found in the intervals between consecutive heartbeats (R-R intervals). This oscillation is known as heart rate variability (HRV). Various methods can be used to estimate HRV, but the extent to which agreement exists between the results obtained by the different methods is not known. In this study HRV, as determined directly from the ECG, is compared to results obtained by time domain analysis, frequency domain analysis, Poincaré graphs and fractal analysis. Results showed that, in individuals with low HRV values, the results obtained by time domain analysis, frequency domain analysis, Poincaré graphs and alpha 1 of fractal analysis are comparable to those calculated directly from the ECG. However, time domain analysis, frequency domain analysis, Poincaré graphs and fractal analysis are less sensitive than direct ECG measurements in individuals with higher HRV.
