Background/Objectives: Heart failure (HF) increases the risk of cognitive impairment (CI). Consequently, early detection and prevention of HF progression may reduce the impact of cognitive decline. The employment of novel echocardiographic imaging techniques, such as myocardial function assessment via speckle tracking strain, allows for the detection of subclinical myocardial dysfunction. The objective of this study is to identify whether speckle tracking strain has the capacity to demonstrate early cardiac alterations in patients with CI. Methods: Following a systematic review across five databases, three studies utilizing left ventricular global longitudinal strain (GLS) and seven studies utilizing left atrial global strain (LAS) were included. Results: In the assessment of myocardial strain, the sample totaled 20,614 individuals, with a mean and median age of 70 years and a predominance of females (55.3%). Left atrial global strain was the myocardial deformation marker that most frequently demonstrated an association with cognitive impairment in the listed studies. Speckle tracking GLS also demonstrated differences between groups. Only one study found no association between sensitive measures of left ventricular and left atrial function and the presence of CI. Conclusions: In conclusion, the results of this systematic review suggest that GLS and LAS are early markers of cognitive impairment.