Anglia Ruskin Research Online (ARRO)
diagnostics-14-00285.pdf (2.65 MB)

Assessing the impact of prolonged averaging of coronary continuous thermodilution traces

Download (2.65 MB)
journal contribution
posted on 2024-04-12, 08:56 authored by Samer Fawaz, Daniel Munhoz, Thabo Mahendiran, Emanuele Gallinoro, Takuya Mizukami, Sarosh A Khan, Rupert FG Simpson, Johan Svanerud, Christopher M Cook, John R Davies, Grigoris V Karamasis, Bernard De Bruyne, Thomas R Keeble

Continuous Thermodilution is a novel method of quantifying coronary flow (Q) in mL/min. To account for variability of Q within the cardiac cycle, the trace is smoothened with a 2 s moving average filter. This can sometimes be ineffective due to significant heart rate variability, ventricular extrasystoles, and deep inspiration, resulting in a fluctuating temperature trace and ambiguity in the location of the “steady state”. This study aims to assess whether a longer moving average filter would smoothen any fluctuations within the continuous thermodilution traces resulting in improved interpretability and reproducibility on a test–retest basis. Patients with ANOCA underwent repeat continuous thermodilution measurements. Analysis of traces were performed at averages of 10, 15, and 20 s to determine the maximum acceptable average. The maximum acceptable average was subsequently applied as a moving average filter and the traces were re-analysed to assess the practical consequences of a longer moving average. Reproducibility was then assessed and compared to a 2 s moving average. Of the averages tested, only 10 s met the criteria for acceptance. When the data was reanalysed with a 10 s moving average filter, there was no significant improvement in reproducibility, however, it resulted in a 12% diagnostic mismatch. Applying a longer moving average filter to continuous thermodilution data does not improve reproducibility. Furthermore, it results in a loss of fidelity on the traces, and a 12% diagnostic mismatch. Overall, current practice should be maintained.



  • Yes



Issue number


Publication title






File version

  • Published version


  • eng

Item sub-type

Journal Article

Affiliated with

  • Medical Technologies Research Centre (MTRC) Outputs