Electrocardiogram interpretation in general practice

The 12-lead electrocardiogram (ECG) is a common diagnostic test available to the GP in the evaluation of patients with cardiac complaints. In daily clinical practice it is important for GPs to know the sensitivity and specificity of their ECG interpretation skills.

The purpose of the present study was to evaluate the ECG interpretation skills of GPs and the value of automatic ECG recorder interpretations in general practice.

A total of 902 ECGs were recorded in a random sample of the population aged 31-51 years in the district of Ebeltoft, Denmark, from December 1991 to June 1992. They were interpreted automatically by an interpretive ECG recorder and by the GPs in the clinic in Ebeltoft, with a cardiologists interpretation as a gold standard. Sensitivity, specificity and predictive values of diagnoses were calculated.

Overall, the sensitivity of abnormal diagnoses made by the GPs (69.8%) was significantly lower (P <0.001) than that of diagnoses made by the interpretive ECG recorder (84.4%). The overall specificity of abnormal diagnoses made by the GP (85.7%) was significantly higher (P <0.001) than that achieved by the interpretive ECG recorder (75.6%).

GPs in this study were good at correcting false-positive diagnoses made by the interpretive ECG recorder. In order to avoid unfortunate reclassifications of true-positive to false-negative diagnoses, GPs are recommended to pay special attention to the diagnoses of ST-segment deviation, T-wave inversion or the presence of Q-waves made by interpretive ECG recorders, when ECGs are used in individual risk assessment.