The goal of this observational study To evaluate the predictive value of left atrial strain for in-hospital outcomes in patients with ST-segment elevation myocardial infarction undergoing PPCI. The main questions it aims to answer are:

Is low parameters of left atrial strain associated early complication ? What is the correlation between LA strain parameters and conventional echocardiographic indices of left ventricular systolic and diastolic function ? Is there more affection to LA strain in certain territory over the others ? What is the correlation between LA strain and LA volume index across infarct territories ? Does LA strain Correlate with TAPSE and PASP to evaluate right-heart interactions ?

The overall trend of ST-segment elevated myocardial infarction has shown an annual increase. Post-infarction heart failure is one of the major adverse cardiovascular events in patients with post-percutaneous coronary intervention.

Therefore, the prediction and accurate assessment of in-hospital outcomes in patients have gained more research and clinical attention.

Left ventricular ejection fraction may no longer be the sole and most reliable predictor of events after a STEMI. Left atrial function may be a comprehensive marker of left-sided cardiac function, as it reflects both diastolic and systolic properties of overall cardiac function.

LA function influences left ventricular filling and cardiac output. Compromised LV function leads to reduced passive LA stretch and filling, contributing to increased LV filling pressures and a subsequent decline in LA function and compliance.

. LA strain is a measurement of atrial myocardial deformation, which is less influenced by cardiac preload and less angle-dependent compared to volumetric indices, such as the left atrial volume index and E/e' ratio.

LA strain is useful in various clinical scenarios, as predicting atrial fibrillation, diastolic dysfunction, and as a measure of LV filling pressure .

LA strain by echocardiographic speckle tracking analysis, is relatively inexpensive, non-invasive and easy to perform, so may be useful as a predictor of in-hospital outcomes.

Previous studies have demonstrated that reduced LA function is linked to clinical outcomes including all-cause mortality.

Inclusion Criteria:

• Adults aged ≥18 years.
• Diagnosed with ST-segment elevation myocardial infarction (STEMI) according to current ESC/AHA criteria
• Underwent successful primary percutaneous coronary intervention (PPCI) within 12 hours of symptom onset.
• Sinus rhythm on admission .
• Trans thoracic echocardiography (TTE) performed within 48 hours of admission with adequate image quality for speckle-tracking analysis.

Exclusion Criteria:

• Previous myocardial infarction or prior PCI/CABG.
• Patients known to have atrial fibrillation or other sustained supraventricular arrhythmias.
• Significant valvular heart disease (severe stenosis or regurgitation).
• Congenital heart disease or cardiomyopathy (hypertrophic, dilated, restrictive).
• Poor echocardiographic window preventing LA strain analysis .
• Mechanical complications (e.g., papillary muscle rupture, VSD, free wall rupture).
• Prior cardiac surgery or known structural lesions that preventing reliable LA measurement.
• patient presenting with killip class III or IV from the start

patients diagnosed with ST-segment elevation myocardial infarction and Underwent successful primary percutaneous coronary intervention and control group to provide baseline parameters for comparing LA strain and other echocardiographic parameters