GRAPHICAL REPRESENTATION OF COMPLEX DATA - DIURNAL PATTERNS OF INITIATIONS OF ATRIAL-FIBRILLATION EPISODES

HNATKOVA, K., ET AL.: Graphical Representation of Complex Data - Diurn al Patterns of Initiation of Atrial Fibrillation Episodes. A construct ion of a purpose designed graphical display is demonstrated in a study investigating the circadian distribution of patterns of RR interval s equences preceding episodes of paroxysmal atrial fibrillation (PAF). B ased on a comparison with a (80%, 120%) range around the median of pre ceding 10 RR intervals, each RR interval is classified as normal, shor t, or long. Classifications of RR intervals in n-tuplets (n = 1,...,5) preceding PAF episodes are used to compute probabilities of individua l types of sequences occurring within 4-hour periods of the day (betwe en 1 am, 5 am, 9 am, 1 pm, 5 pm, and 9 pm). Graphical representation o f the data is proposed using a hierarchy of bar graphs. The graphical system has been filled with data of 327 atrial fibrillation episodes r ecorded in 46 24-hour ECGs in PAF patients. The graphical analysis sup ports a link between PAF initiation and cardiac autonomic status.