Development of Matlab Algorithm to Process Pressure Waveforms from Isolated Perfused Heart Experiments

Abstract

The Langendorff isolated heart preparation allows for the collection of pressure waveforms in animal heart specimens. The data obtained provides information on physiological parameters such as left ventricular systolic pressure, rate of contractility, rate of relaxation, heart rate, and aortic pressure. Processing this data allows researchers to assess and monitor heart function in a close-to-physiological environment, but data processing may be time-consuming. Commercial software packages are available to process the data collected from the isolated heart experiment, but these packages are expensive and may not be adaptable to the exact application that researchers need. Our group has developed an easily customizable Matlab algorithm which includes a graphical user interface for intuitive processing. The algorithm reads text files containing raw aortic and left ventricular pressure data. From this information, it extracts and plots values for maximum dP/dt, minimum dP/dt, peak left ventricular end systolic pressure (LVSP), left ventricular end diastolic pressure (LVEDP), left ventricular developed pressure (LVDP), mean time from LVEDP to LVSP, heart rate, and mean aortic pressure. The output information includes the standard deviation of the measurements. The input of the algorithm can vary from one to multiple files of data at a time, which allows for comparison of data collected at different time intervals in the experiment. This feature is very useful to monitor the progression of heart function during the experiment and the reproducibility of the experiments. The applicability of the algorithm is beyond the isolated heart experiment, because it could be modified for use in any application that requires processing of pressure waveforms.