Researchers at King's College London have developed a new method for quantifying arrhythmias in isolated hearts using ADInstruments PowerLab data acquisition systems
The research is benefiting from PowerLab's Heart Rate Variability (HRV) Module for Chart software.
PhD student Erika Kennington, under the direction of Professor Mike Shattock, is investigating the functional role of the small membrane protein phospholemman in mouse hearts.
Kennington is using PowerLab systems and Chart software to analyse the functional and electrophysiological characteristics of isolated mouse hearts where the phospholemman gene has been deleted.
"While recording contractile function from the hearts using intraventricular balloons, we realized that some of our interventions were causing an increase in the number of arrhythmias", reports Kennington.
"We decided to see if we could use the statistical power of the HRV Module to provide us with a quantitative index of arrhythmias".
The HRV Module, an add-on for Chart software, is designed to measure natural variations in heart beat-to-beat intervals.
The module is normally used with ECG recordings, and rapidly generates statistical analyses, including the mean of normalised RR intervals (mean NN) and the standard deviation of the differences between adjacent NN intervals (SD of delta NN).
The King's College scientists determined that the ratio of SD of delta NN to mean NN produced an 'arrhythmia score'.
The HRV Module was able to derive the statistics from left-ventricular pressure recordings and the analysis was essentially independent of heart rate, and thus appropriate for isolated heart studies.
"This almost instantaneous analysis can be applied to an entire experiment containing up to 10, 000 heartbeats", says Kennington.
"It is simple, fast and much less subjective than previous methods of arrhythmia quantification".
