What is the diagnosis?

Old anterior wall myocardial infarction and left atrial overload.

Left atrial overload is seen as prominent negative component of P wave lead V1. There is poor progression of R waves in anterior leads with QS complex (only Q wave and no R wave) in lead V3 and qr in V4. T waves are inverted in leads I, II, aVl and V4 to V6. ST segment is almost isolectric. These findings together indicate that the myocardial infarction was remote. If the ST elevation is persisting for a long period after myocardial infarction, it is considered as a feature of left ventricular aneurysm.