Detection of Heart Rate Turbulence Using an Extended IPFM Model

Abstract:
In this study, the IPFM model is extended to account

for the presence of ectopic beats and heart rate turbulence

(HRT). Based on the model extension, a new approach to

characterize HRT is presented based on a set of Karhunen-

Loeve (KL) basis functions. The three most significant

basis functions possess attractive physiological interpretations

which reflect the difference in heart rate prior to the

ventricular ectopic beat (VEB) compared to after HRT, an

“average” HRT, and a delayed “average” HRT, respectively.

HRT detection is based on the IPFM model extension,

and involves a test statistic that results from a linear

model. The HRT test statistic was studied on patients who

underwent hemodialysis treatment. The goal was to distinguish

between patients considered to be hypotensionresistant

(HtR) and hypotension-prone (HtP). The results

show that the test statistic of the two groups formed two

non-overlapping clusters. The HtR-cluster exhibited much

larger values than did the HtP-cluster (mean values 51 and

2, respectively), suggesting that HRT is mostly present in

HtR patients.