In cardiac pacemaker implantation, the commonly used leads are passive fixation lead and active fixation lead. The passive fixation lead is widely used because of its easy operation and low price. It have “tines” at the end of the lead, so that it can be embedded in the trabecular muscles acutely, after a period of time, the myocardium around it will fibrose to secure it further . With the continuous development of pacing technology, the utilization rate of active fixation lead is getting higher and higher . The tip of active fixation lead is a screw, which rotates out of the spiral structure during implantation and rotates into the myocardium, which can be placed anywhere in the cardiac cavity.
In this case, both the atrial and ventricular leads are active fixation leads. For the atrial leads, the passive fixation leads need to be fixed in the right atrial appendage, where the trabecular muscles are dense, however, due to the anatomical specificity of the mirror-image dextrocardia, it is difficult to reach the accurate position by using passive fixation leads, which increases the radiation exposure time of the patients, and is easy to fall off.
The active fixation leads can be fixed anywhere in the atrium, it is easier to find the position with optimal sensing and pacing threshold, and reduce the operation time, so we fix the atrial leads to the free wall of the right atrium. For a long time, many people think that this position is very thin, and it is easy to cause perforation when fixing the electrode. However, there is no significant difference in postoperative complications (such as perforation, pericardial effusion, dislodgement), pacing sensing, pacing threshold and impedance [14–15]. In addition, the use of active atrial lead fixation can reduce the incidence of dislodgement [16–17], and significantly reduce the bed rest time and duration of hospital stay of patients. Furthermore, atrial active fixation lead has a lower and more stable pacing threshold .
Because the anatomical specificity of the mirror-image dextrocardia, the operation during the implantation is opposite to that of a normal person, it is necessary to be fully familiar with and informed its anatomical characteristics and the trend of the blood vessels before the operation to help determine the path of lead implantation. While positioning the leads, we can combine the positive position, lateral position and oblique position under fluoroscopy, determine the position of the leads from different angles, do not push blindly and cause surgical complications. During the operation, invert the fluoroscopic image,perform the operation under the posterior anterior view༌which is more in line with the usual operating habits, can increase the success rate of the operation, and can also reduce misoperations, which can cause vascular and cardiac injuries.