The Role of Myocardial Strain Imaging in the Pre- and Post-Operative Assessment of Patients with Single Ventricle.

The term "single ventricle" refers to a wide range of cardiac structural and functional abnormalities which cause the morphologically right or left ventricle to be hypoplastic or functionally inadequate. Patients with single-ventricle physiology have followed a series of palliative surgeries, resulting in the dominant ventricle supporting only the systemic circulation and the systemic venous return draining directly to the pulmonary arteries. Such patients present a progressive decline in myocardial performance, and their management is associated with high morbidity, mortality and resource usage. At each management step, imaging is critical in eligibility assessment, pre-procedural planning and prompt detection of myocardial dysfunction. However, the complex and asymmetric geometry of the dominant ventricle and its segmental wall motion abnormalities make the echocardiographic evaluation of myocardial performance in these patients rather challenging. Consequently, conventional 2-dimensional echo functional parameters, such as ejection fraction by Simpson's biplane method or shortening fraction by M-mode, is complex and often not feasible to apply. On the other hand, speckle-tracking echocardiography is angle and geometry independent and has better reproducibility. As such, it constitutes an appealing method for assessing myocardial function in patients with single-ventricle hearts. Therefore, this review aims to investigate the role of myocardial strain imaging by speckle-tracking echocardiography in the pre-and post-operative assessment of patients with single-ventricle hearts.