Quantitation of ventricular arrhythmias.

Development of a computer-aided system for routine quantitation of spontaneously occurring ventricular arrhythmias in isolated perfused hearts is described. The technique essentially involves statistical treatment of electrocardiographic data to determine beat interval standard deviations. To minimize standard deviations arising from changes in heart rate, mean R-R intervals and standard deviations of 1-min sets of data are grouped and subjected to one-tailed analysis of variance. Residual standard deviation (derived from the difference between total variation and between set variation) expressed as a percentage of group mean is utilized as the Rhythm Disturbance Unit. It is proposed that this system can be used to facilitate investigations into mechanisms underlying arrhythmogenesis and in addition may have potential application in the screening of anti-arrhythmic interventions.