Aims: This study aimed to summarize the transthoracic echocardiography (TTE) characteristics of cardiac tumors with different pathologies. Methods:The data of 399 patients with cardiac tumors confirmed by pathology, who had undergone surgical resection were consecutively collected in our hospital between January 1, 2011 and December 31, 2019. The TTE characteristics were summarized and compared with the pathology.Results: Mean patient age was 49.8±15.7 years (22 children and 377 adults), and 62.2% were female. Of the tumors, 90.5% (361) were primary and 9.5% (38) were secondary. Further, 88.7% (354) were benign and 11.3% (45) were malignant. Of the primary tumors (96.1% benign and 3.9% malignant), 84.2% were myxomas, followed by 3.5% lipomas and 1.5% fibromas in adults, while in children, 31.8% were rhabdomyomas and 22.7% were fibromas. The most common type of secondary cardiac tumor was malignant liver carcinoma metastasis (39.5%) and benign intravenous leiomyomatosis with cardiac extension from the uterus (18.4%). TTE features of myxoma showed four variation types among 8.9% of myxomas: liquefaction (anechoic region mostly), calcification (hyperechoic range with a shadow), multiple nodules, and high proliferative activity (a large irregular mass with a wide base and a high Ki67 index). The TTE characteristics of some common benign non-myxoma tumors had specific findings.The TTE features of malignant tumors mostly showed hypoechogenicity, an unclear boundary, a wide basement, and multi-chambers or tissue invasion. Conclusions:Most cardiac tumors have typical ultrasonic manifestations. Preoperative echocardiography could roughly judge cardiac tumor type and may be helpful for guiding clinical treatment decisions.

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Abstract:To support doubly fed wind turbine (DFWT) groups in offshore wind farms, this paper proposes a distributed coordinated control based on the Hamiltonian energy theory. This strategy provides global stability to closed-loop systems and facilitates output synchronization. First, a model of a DFWT is realized as a port-controlled Hamiltonian system with dissipation (PCH-D), and the single-machine model is expanded into a multi-machine model of a wind turbine group. Then, by using the design methodology of distributed Hamiltonian systems, a distributed coordinated control is presented for a multi-machine PCH-D system. Furthermore, to investigate failures in wind turbine groups, they are divided into two cases: the separation of failed machines from the system, and the grid-connected operation of failed machines after a fault. These cases correspond to undirected and directed graphs, respectively. Finally, simulations prove that distributed coordinated control enhances the reliability and autonomy of wind turbine groups in offshore wind farms.

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