A Comparison oftheMultiple andSingle LeadProcedures

SUMMARY AND CONCLUSIONS 1. Previous studies reveal lack of agree-ment about the value of an electrocardiogram in the detection of heart disease. Data collected on adult volunteers who were examined by the Framingham Heart Disease EpidemiologyStudy appeared to be ideally suited to study this problem. 2. The completed clinical records of 2,000 such individuals were used to determine theefficiency of the 12 lead electrocardiogram and the single lead I electrocardiogram as mass screening procedures for detecting heart dis-ease.3. Theoretic and practical reasons for selecting the lead I electrocardiogram are indicated. The criteria used in detecting normaland abnormalleadI electrocardiograms are presented anddiscussed.4. The 12-lead electrocardiogram correctlyclassified 89.3 per cent of the clinically normalpersons as normal but incorrectly classified7.3 percent as doubtful and 3.4 cent as abnormal. The 12-lead electrocardiogram in- correctly classified as normal 64.1 per cent of the persons