Value of the 12-lead resting electrocardiogram for the diagnosis of previous myocardial infarction in paced patients

Abstract

Aim This study was conducted to assess the clinical value of the 12-lead electrocardiogram (ECG) for the diagnosis of previous myocardial infarction (MI) in permanently paced patients. Methods A total of 107 unselected patients with permanent pacemakers were retrospectively studied and divided into 3 groups: group 1 (control group): 38 patients without a history of MI (mean age, 67 ± 16 years; 20 men; ejection fraction 63% ± 8%); group 2: 44 patients (mean age, 72 ± 11 years; 41 men) with documented previous MI (21 anterior, 23 inferior; ejection fraction 38% ± 13%; P < .0001 vs group 1); group 3: 25 patients (mean age, 71 ± 14 years; 24 men) with biventricular pacing for severe heart failure (16 ischemic, 9 nonischemic; ejection fraction 28% ± 8%; P = .001 vs group 2, P < .0001 vs group 1). A surface 12-lead ECG with full ventricular capture was used for analysis. Comparing group 1 and group 2, the sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy of 5 criteria was calculated: (1) Cabrera's sign (notching in the ascending limb of the S wave in lead V 3, V 4, or V 5); (2) Chapman's sign (notching of the R wave in lead I, aVL, or V 6); (3) presence of a qR in lead I, aVL, or V 6; (4) notching of QRS in lead II, III, or aVF; (5) presence of a qR in lead II, III, or aVF. Results To detect prior MI, sensitivity was moderate for Cabrera's sign (63.6%) and poor for all other ECG criteria ranging from 9.1% to 40.9%. Specificity was relatively high for all ECG criteria ranging from 81.6% to 100%. Combining all 5 ECG signs increased sensitivity to 86.4%, with a specificity of 65.8% and an overall accuracy of 76.8% for the diagnosis of previous MI. None of the 5 criteria was particularly useful to assess the site of prior MI. In patients with biventricular pacing, the accuracy of the 5 ECG criteria was poor and the presence of a qR wave in lead I, aVL, or V6 appears nonspecific and related to pacing site. Conclusion The ECG diagnosis of previous MI in paced patients remains a difficult challenge but the presence of 1 or more of the aforementioned ECG criteria may be clinically useful to detect previous MI, suggesting that these ECG signs should be widely taught during medical training. However, in patients with biventricular pacing, these ECG signs are of no value.