Notched P Wave

Report:

Sinus rhythm

Left atrial abnormality (LAA)

Widely notched P wave

Sino-atrial exit block

Probable atrial infarction

Comment:

The wide P wave (0.18”) is produced by an atrial conduction defect, usually involving the interatrial tract (Bachman’s bundle). It may be the result of ischæmic injury, as in this case, or left atrial enlargement or hypertrophy (or both). The notching, typical of P mitrale in mitral stenosis, is deemed diagnostically significant when the notch is 0.04” wide; in this case, it is 0.08” - 2 mm - wide.

Below, second degree 2:1 block (middle) is replaced by atrial fibrillation with third degree block and junctional rhythm (bottom). These recordings are taken on lead V1; ST elevation there reflects right ventricular infarction.

If you have any suggestions for or feedback on this report, please let us know.