Background: Despite the known benefit of thrombolysis it remains underutilized among eligible patients with acute myocardial infarction. We sought to determine whether potential errors in ECG interpretation might be a contributing factor and to what extent clinical history, a checklist outlining recognized inclusion criteria and a computerized interpretation would influence reliability and accuracy.
Methods: Seventy-five ECGs were interpreted on 8 separate occasions by 9 clinicians (3 cardiologists, 3 cardiology fellows, 3 medical residents) according to a 2 × 2 × 2 factorial design.
Results: The overall level of agreement among all raters was substantial with a kappa (
) of 70.4%. Intra-observer ECG reading reliability was stronger among cardiologists (CC) as compared with cardiology fellows (CF) and medical residents (MR). Similarly, inter-observer reliability was substantial to very good and a gradient was seen with greater reliability among CC, followed by CF, then MR (
P = 0.0013). CC recommended thrombolysis significantly more frequently (
p < 0.001)="" than="" either="" cf="" or="" mr.="" trainees="" were="" biased="" by="" the="" presence="" of="" a="" computerized="" ecg="" interpretation="" resulting="" in="" a="" decision="" to="" recommend="" thrombolysis="" administration="" less="">
Conclusion: The reliability of ECG interpretation for deciding to administer thrombolysis was substantial; there was a gradient from lowest to highest commensurate with training and experience. Errors in thrombolysis eligibility are influenced by clinical history and the presence of a computerized ECG interpretation among less experienced clinicians.
acute myocardial infarction - thrombolysis - electrocardiography - computerized ECG interpretation