Expert system diagnosis of wide complex tachycardia

The differentiation between ventricular tachycardia (VT) and a supraventricular tachycardia with aberrancy (SVT) in a patient with a wide complex tachycardia is often difficult. To help in this differentiation, a rule-based expert system was developed using a commercially available expert system shell running under the MS-DOS operating system. The user is queried for the presence of various abnormalities on the twelve lead electrocardiogram. From published data, each abnormality is assigned a probability based on the positive predictive value of the abnormality for VT and for SVT. By combining the positive predictive values, the expert system assigns a final probability for VT and for SVT. In addition, the expert system provides a compilation of the rules applied. In 283 tracings, the sensitivity for VT was 98% and the specificity was 60%. The sensitivity and specificity for SVT were 40% and 99%