Patent ID: 8600485

Claim:
A method of ventricular repolarization analysis using an electrocardiogram, the method comprising the steps of: providing an ECG machine and coupling the ECG machine to a patient, using the ECG machine to measure a continuous course of ECG of the patient at rest, then at increased heart rate, and then at rest again, determining a continuous succession of heartbeat intervals CD and internal intervals AB within the measured ECG signal and instrumental variables using the measurements made using ECG, determining CDx=CD −mean( CD ), and ABx=AB −mean( AB ) from the detected AB and CD values, then, determining parameters a 1 , b k+1 , and b k+2 by means of minimization of the mean quadratic deviation in the whole course of measurement between the measured ABx intervals and model ABmx values, which determination is made using the formula ABmx ( i )= b k+1 CDx ( i−k )+ b k+2 CDx ( i−k− 1)− a 1 ABmx ( i− 1), where CDx(i) and ABmx(i) are the i-th values of the CDx and ABmx variables and wherein k is delay between variables, determining frequency and step response of AB/CD couplings using a transfer function H ABx / CDx ⁡ ( z ) = b k + 1 ⁢ z - k + b k + 2 ⁢ z - ( k + 1 ) 1 + a 1 ⁢ z - 1 determining the following three parameters of physiological relevance by means of said transfer function: transfer gain (Gain S ) between AB variability (ABvar) and CD variability for slow changes in heart rate given by the extent of steady change AB at a unit step CD, transfer gain (Gain F ) for rapid changes in heart rate, given by the amplitude of an instantaneous change of AB interval at unit step CD, and number of T heartbeats, when the value of the AB interval reaches a certain percentage of the steady state after a step change of CD intervals; determining a corrected value ABc for the excitation used during measurement by means of the formula: ABc=ABst +(1 −CDst )−Gain S , where ABst and CDst are mean values of the steady state of intervals AB and CD, determining a model value ABm using the formula: ABm=ABmx +mean( AB ), and using the model value ABm to calculate the AB variability (ABvar) independent of the CD interval, wherein ABvar is the variability of the difference AB−ABm, and evaluating ventricular polarization using at least one of said determined parameters Gain S , Gain F , T heartbeats, ABc, and ABvar.