Apparatus and method for predicting cardiac arrhythmia by detection of

Abstract

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.