The heart is a complicated organ. Stimulation by heart current causes myocardial contraction to pump out blood and makes the blood to circulate in the blood vessel. The heart current passes through the atrium and then the ventricle to cause myocardial contraction. The myocardium rhythmically contracts under the action of heart current. However, the advance in age or the change in pathological and physiological characteristics of the heart causes contraction disorder and abnormal rhythm of the heart. One of the methods to treat arrhythmia is septal ablation, that is, making the abnormal heart current loop open through an interventional surgery. To perform ablation, it is necessary to guide the catheter with an ablation electrode to reach the left atrium. This is usually performed by femoral artery puncture, whereby the electrophysiology catheter with an ablation electrode is delivered to the left atrium under X-ray image observation, the electrode is placed against the orifice of the pulmonary vein, the site of abnormal heart current loop that generates arrhythmia is determined by collecting electric signals, and the discharge energy or other energy generated by the ablation electrode brings about lesion degeneration or coagulative necrosis to the tissue near this site, to thereby cut off the abnormal heart current loop. The energy for use in ablation can be radio frequency current, direct current, microwave, ultrasonic wave or laser.
The key to electrophysiology ablation is positioning of the electrode, namely to determine the site to be ablated in a quick and precise manner. U.S. Pat. No. 6,837,886 B2 proposes an electrophysiology ablation device, whose positioning method is carried out by an openable meshed flat disk concealed in the catheter head. During the process of vein puncture, the disk is concealed in the catheter head, and after the catheter head is inserted into the orifice of the pulmonary vein, the disk is opened to abut against the orifice of the pulmonary vein. The disk is braided from a metal wire, which has electrically conductive function, and is itself an electrode that generates electric pulses once the power is on to carry out circumferential ablation on the orifice of the pulmonary vein. That invention is mainly defective in the following aspect: due to the difference in sizes and shapes of the orifices of the patients' pulmonary veins, it is very difficult in practical operation to abut the meshed flat disk completely against the orifice of the pulmonary vein, but instead usually only in a slanting or partial manner, so that it is impossible to carry out ideal circumferential ablation of the orifice of the pulmonary vein, and adversely affecting the therapeutic effect.