Introduction
The survival rate of cancer patients has been significantly improved in recent decades. Because of the development of early diagnosis techniques, improved in the level of treatment and the implementation of multidisciplinary treatment of cancer, and advances in adjuvant chemotherapy and radiotherapy[1]. Although with the development of anti-tumor drug therapy towards the direction of individual and targeted therapy, its toxic and side effects should not be ignored. Research has shown that about half of cancer deaths are caused by non-cancer causes, and cardiovascular disease plays an important role[2].
Anthracyclines are secondary metabolites produced by Streptomyces and are one of the most effective anticancer drugs at present. It mainly includes daunorubicin, Adriamycin, epirubicin, pirarubicin, mitoxantrone and so on. Although the field of cancer treatment has changed dramatically in recent decades, anthracyclines remain the cornerstone of modern chemotherapy regimens for many cancers[3, 4]. However, the most severe adverse reaction of anthracyclines is the cardiotoxicity caused by anthracyclines. Numerous trials have indicated that most of the cardiotoxicity caused by anthracyclines are persistent and non-reversing, especially the first use of anthracyclines easily cause cardiac damage. Therefore, early detection of cardiac insufficiency can implement cardiac protection strategies before late and potentially irreversible changes in cardiac function[5, 6].
Echocardiography is a well-known non-invasive technique for assessment of cardiac systolic and diastolic function, and it is the most commonly used method for early identification and evaluation of cardiotoxicity caused by antineoplastic drugs. Left-ventricular ejection fraction (LVEF) is the most frequently used index to evaluate left ventricular systolic function by conventional echocardiography, and the decrease of LVEF is related to heart failure. However, its sensitivity to early identification of cardiotoxicity is still controversial[7]. The cardiotoxicity induced by anthracyclines was mostly positively correlated with the dose, and in China the dose of anthracycline in the treatment of breast cancer is relatively low. Therefore, more sensitive monitoring methods are needed to monitor the cardiotoxicity associated with low-dose anthracyclines. In recent years, with the development of echocardiography technology, 2D and 3D speckle‐tracking echocardiographic parameters have been proved to be able to detect preclinical abnormalities reliably at an early stage [8-10]. Standard echocardiography can detect abnormalities in the presence of obvious clinical symptoms. In the preclinical state, strain imaging can make up for its deficiency and is of great help in early diagnosis and define prognosis.[11].
However, because of the different distribution of myocardial fibres, some areas of the myocardium may be more prone to dysfunction[12]. This study aimed to compare the role and significance of 2D strain and 3D strain in the detection of early segmental dysfunction, and to explore which is more meaningful, including 3D global strain, longitudinal strain, radial strain and circumferential strain.