[Electrocardiographic sign of secondary atrial tumor presentation].

Two cases of intravital diagnosis of left atrial tumor secondary to lung cancer and esophagus cancer are presented. The myocardial alteration was caused by direct invasion of primary tumor. In both cases the PQ (PR) segment depression was found on ECG, which could reflect neoplastic lesion of the atrium. We proposed to consider this phenomenon as ECG marker of secondary atrial malignancies.