Transthoracic Echocardiography

The leadless pacemaker is a novel pacing technology that has emerged in recent years. Compared with conventional lead pacemakers, its design avoids many complications associated with leads and pacemaker pockets, including lead fracture, pocket infection, and venous access stenosis. Because of its small size and the absence of a pacemaker pocket or pacing lead, the leadless pacemaker is particularly suitable for patients with contraindications to conventional pacemaker implantation, including patients undergoing hemodialysis, patients with recurrent pocket infection, and patients without suitable vascular access. Currently, leadless pacemaker implantation is performed primarily under fluoroscopic guidance. Fluoroscopy provides real-time intraoperative anatomical localization information but places high demands on the operator's technical skills and the precise intraoperative positioning of the pacemaker. However, procedures performed under fluoroscopic guidance require dedicated procedure rooms and radiation-generating equipment. Such large-scale equipment is expensive, and it requires special protective measures that make the surrounding walls, doors and windows meet the protection standards, so as not to cause harm to the surrounding environment and personnel. When procedures are performed under fluoroscopic guidance in dedicated catheterization laboratories, both operators and patients are exposed to potential health risks, and fluoroscopy-guided procedures are contraindicated in some pregnant women. In addition, X-ray imaging remains two-dimensional, and visualization may be inadequate in some patients because of individual anatomical variation, potentially increasing procedural difficulty. Therefore, exploring a radiation-free, real-time, and accurate guidance method has become a key approach to improving the success rate and safety of leadless pacemaker implantation.

Septic shock is a critical condition associated with high mortality. Transthoracic echocardiography is widely used to evaluate cardiac function and guide treatment. Left and right atrial strain (LAS and RAS) measured via speckle tracking echocardiography have shown prognostic value in cardiovascular diseases. However, differences exist between echocardiographic software, leading to challenges in result comparability. This study aims to compare LAS and RAS measurements between ECHOPAC and UWS software, evaluate AutoStrain technology, and assess reproducibility across observers. The study is non-interventional and will use retrospective echocardiographic data from patients treated for septic shock. The findings will contribute to improving measurement standardization in critically ill patients.