Crochetage sign in ASD
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Crochetage sign in atrial septal defect was described by Heller J et al in 1996 in study published in the Journal of American College of Cardiology. It is a notch near the apex of the R wave in inferior leads. They noted a sensititvity of about 73% and specificity of 92% if the sign was present in all the three inferior leads. Early disappearance of the crochetage sign after surgical correction of atrial septal defect was found in 35% of cases even when the incomplete right bundle branch block (RBBB) pattern was persisting. The ECG illustrated above shows the notch at the apex of the R wave in leads II and aVF and a notch in the ascending limb of lead III.
This ECG also shows right atrial overload as evidenced by P wave amplitude of 0.3 mV in lead II. Incomplete RBBB pattern is seen as slurred S waves in lead I and rSrS pattern in V1.