Electrocardiographic Identification of Left Atrial Enlargement Ev Alua Tion of a Widely Used Computerized Ecg Interpretation System

The computerized interpretation of the electrocardiogram (ECG) is widely used in clinical practice. In this study, the diagnostic accuracy of a computerized ECG analysis system in determining le!\ atrial enlargement (LAE) was compared to readings made by two experienced cardiologists using LA measurements derived from echocardiography (echo) as a gold standard. LA size and the presence or absence ofLAE on ECG was determined by computer analysis and by the cardiologists' readings in 181 patients undergoing routine echo. The computer classified patients according to the presence ofLAE (n = 30), "consider" LAE (n = 59) and normal LAE (n = 92), whereas the echo identified 86 patients witl1 normal LA size and 95 patients with varying degrees of LAE. ECG reading by both the computer and cardiologists showed a high specificity for different degrees ofLAE, whereas sensitivity was generally poor for all sets of readings. Negative-predictive accuracy was high but positive-predictive accuracy was only fair to poor, for both the computer and the cardiologists. Both computerized and physician ECG readings identified patients with normal LA size but tended to overstimate the presepce of LAE. New algorithms are required before LAE can be determined reliably from routine ECG in clinical practice.