The Role of Advanced Echocardiographic Parameters of the Left Atrial Function in the Incidence of Cryptogenic Ischemic Stroke: A Review

Stroke is one of the primary causes of morbidity and mortality worldwide, including a large proportion of cryptogenic strokes. Long-term electrocardiographic monitoring is beneficial in prospective studies for detecting atrial fibrillation in patients with cryptogenic stroke. This review aimed to evaluate the advanced echocardiographic parameters and their roles in assessing left atrial (LA) function in the incidence of cryptogenic and ischemic strokes. Main resources, including PubMed, Scopus, and ISI Web of Science databases, were evaluated for articles published in English from 2010 until May 2021. LA echocardiographic parameters such as LA strain and strain rate, isovolumetric relaxation time (IVRT), the mean left atrial volume index (LAVI), LA reservoir volume, systole strain rate (SSR) of left atrial appendage, and lack of LA function response to maximal exercise as measured by the LA ejection fraction during rest and exercise could be considered for assessing the risk of cryptogenic strokes and ischemic strokes. The results indicated that increased LA volumes and reduced LA strain rate were correlated with cryptogenic stroke. Advanced parameters of LA function, measured by speckle tracking echocardiography, such as strain and strain rate values in different parts of the cardiac cycle, in addition to standard measures of LA function such as LA ejection fraction and LAVI, will define an excellent understanding regarding LA myopathy and risk assessment of cryptogenic stroke, independent of considering conventional cardiovascular risk factors.