12-Lead ECG interpretation by database comparison

Automated ECG interpretation is most often a rule-based expert system, though experts may disagree on the exact ECG criteria. One method to automate ECG analysis while indirectly using varied sets of expert rules is to base the automated interpretation on similar ECGs that already have a physician interpretation. The aim of this study is to develop and test an ECG interpretation algorithm based on such similar ECGs.

The study database consists of approximately 146,000 sequential 12-lead 10 s ECGs taken over the course of three years from a single hospital. All patient ECGs were included. Computer interpretation was corrected by physicians as part of standard care. The ECG algorithm developed here consisted of an ECG similarity search along with a method for estimating the interpretation from a small set of similar ECGs. A second level of differential diagnosis differentiated ECG categories with substantial similarity, such as LVH and LBBB. Interpretation performance was tested by ROC analysis including sensitivity (SE), specificity (SP), positive predictive value (PPV) and area under the ROC curve (AUC).

LBBB was the category with the best ECG interpretation performance with an AUC of 0.981 while RBBB, LAFB and ventricular paced rhythm also had an AUC at 0.95 or above. AUC was 0.9 and above for the ischemic repolarization abnormality, LVH, old anterior MI, and early repolarization categories. All other morphology categories had an AUC over 0.8.

ECG interpretation by analysis of ECG similarity provides adequate ECG interpretation performance on an unselected database using only strategies to weight the interpretation from those similar ECGs. Although this algorithm may not be ready to replace rule-based computer ECG analysis, it may be a useful adjunct recommender.