2.4 Measuring the distance between the pacing electrode and the coronary artery
As shown in Figure 2, using a Beijing Sichuang technology system, we measured the vertical distance from the tip of the pacing electrode to the anterior descending artery during systole, with the positive head position (AP + CRA 30°), foot position (AP + CAU 30°), left shoulder position (LAO 30° + CRA 20°) and spider position (LAO 45° + CAU 30 °). The maximum value was recorded, which was closest to the actual spatial distance between the tip of the pacing electrode and the anterior descending artery. The measurement results are represent using two decimal places. The same method was used to measure the distance from the tip of the pacing electrode to the posterior descending branch of the right coronary artery and to the posterior branch of the left ventricle.