Complex networks tools for resolving heart rate dynamics
|Danuta Makowiec 1, Joanna Wdowczyk 2, Zbigniew R. Struzik 1,3|
1. Gdansk University, Institute of Theoretical Physics and Astrophysics, (IFTiA UG), Wita Stwosza 57, Gdańsk 80-952, Poland
We propose a network representation of time series which consists of time intervals between subsequent heart contractions, called RR intervals, as a way to qualify and quantify short-term patterns of the overall complex heart rate dynamics. In particular, a directed network of increments in RR-intervals is constructed based on a Holter recording. The vertices are labeled by the values of the observed RR increments, the edges link consecutive increments. The network is weighted - the edge widths show how often a given pair of RR-increments occurs in the signal. The proposed representation allows to identify the arrhythmic events in a patient oriented way.
As an example, a network is constructed from the nocturnal Holter recording of a male heart-transplant patient, who was 17 years following surgery, and had a good overall health status. Different rhythm patterns are found when scanning the recorded signal, thanks to the noticeable transition in the network structure: the basic rhythm which has a mean time interval about 900 ms, and another rhythm, a slower one, which is strongly variable, however well-pronounced during sleep. It occurs that the second rhythm is beginning with a large deceleration of 400 ms, which is followed by two compensating accelerations. Cardiologists refer to such rhythm as Mobitz type I atrioventricular block. This block is a relatively benign form of atrioventricular block because it is often related to periods of high vagal activity what does not need much care. However, it can also occur in generalized disease of the conducting tissue what needs further observation by a doctor.
Presentation: Oral at 8 Ogólnopolskie Sympozjum "Fizyka w Ekonomii i Naukach Społecznych", by Danuta Makowiec
See On-line Journal of 8 Ogólnopolskie Sympozjum "Fizyka w Ekonomii i Naukach Społecznych"
Submitted: 2015-08-10 11:18 Revised: 2015-08-10 11:31