Apparatus and method for predicting cardiac arrhythmia by detection of micropotentials and analysis of all ECG segments and intervals

摘要

An apparatus and method for the acquisition and analysis of electrocardiogram signals, to non-invasively detect and quantify presence of abnormal cardiac conduction patterns in patients at risk of heart disease, e.g. ventricular tachycardia; atrial fibrillation and flutter. Signals from the orthogonal X, Y and Z surface leads are amplified, digitized and either stored for later processing, or processed immediately. The incoming beats can either be R wave-triggered, aligned and ensemble-averaged for studies of patients at risk for ventricular pathologies such as ventricular tachycardia, or P wave-triggered, aligned and ensemble-averaged for studies of patients at risk for atrial pathologies, e.g. atrial fibrillation and flutter. QRS onset and offset, and P wave onset and offset, are calculated for ventricular and atrial post-analysis applications, respectively. The windowed Fourier transform of the second derivative (acceleration) of the signal-averaged ECG is calculated for particular regions of interest for each lead, including the intra-QRS, ST-segment, T and P wave regions. A novel Spectral Change Index, calculated from the resulting "acceleration spectrum" for each lead as well as the composite (X+Y+Z) lead, serves to quantify the degree of spectral "fragmentation" within a prespecified bandwidth. It thereby provides a quantitative index to help stratify patients at risk for potentially lethal cardiac (atrial and ventricular) pathologies.