Cryptogenic stroke is a type of stroke in which the cause of the blood clot cannot be identified, leaving many patients without a clear treatment plan and at high risk for another stroke. Current medical guidelines recommend blood-thinning medication (anticoagulation) only when atrial fibrillation (AF) -an irregular heart rhythm- can be documented. However, AF may occur silently and remain undetected. Long term implantable (placed invasively under the skin) devices may be needed to capture these episodes. AF is known to develop from disease of the left atrium, the upper chamber of the heart that receives blood from the lungs. When the left atrium does not contract normally, blood flow may slow down, increasing the risk of clot formation. Nowadays, the left atrial (LA) function can be quantified precisely using a noninvasive ultrasound technique called strain imaging. This study aims to determine whether reduced LA function is associated with cryptogenic stroke and its recurrence even when AF is not observed. If such an association is confirmed, LA strain could serve as a new biomarker to identify patients at risk, earlier than the development of overt AF, enhance preventive measures to reduce recurrent strokes. Because echocardiographic strain imaging is safe, cost-effective, and widely available, it may become an important tool for improving care in this high-risk population.