The study aimed to asses left atrial longitudinal strain (PALS)furthermore, its job in anticipating atrial fibrillation (AF) event in patients with expanded cardiomyopathy (DCM) with LVEF under 40% by utilizing dot following echocardiography (STE). in this examination we arbitrarily doled out 100 Egyptian patients with enlarged cardiomyopathy who were additionally ordered into two gatherings: SR gathering, 50 patients with sinus cadence and AF gathering, 50 patients with constant AF. Left atrial longitudinal strain (PALS) was estimated utilizing 2D STE. Left atrial longitudinal strain (PALS) values were altogether lower in AF bunch than in SR gathering (7.44 ±1.49% versus 15.82 ±3.15%; p <0.001). ROC examination showed that PALS under 11.1% (AUC 0.981; 95% CI 0.958–1.000; p < 0.0001) recognize SR from AF patients with DCM. End: In patients with DCM and atrial fibrillation the left atrial longitudinal strain (PALS) values are altogether lower than in patients with AF than the individuals who had saved sinus cadence, PALS cut-off worth <11.1% was appeared to have the best demonstrative exactness in foreseeing event atrial fibrillation in DCM patients and LVEF < 40%.