房颤射频消融的热点关新 ppt课件.ppt

这种说法体现了房颤发生后的连缀现象，即房颤持续时间越长就越容易持续，即使中间转复为窦律也容易再发房颤。这是由于房颤的发生可引起心脏电重构与解剖学重构，成为房颤持续及复发的基础。 上述连缀现象恰恰解释了房颤发病的临床特征，即随着房颤发生时间的推移，患者房颤发作越频繁，持续时间越长，一段时间后，阵发性房颤将进展为持续性或慢性房颤。这警示临床医生，患者初发房颤后应尽快转复为窦律，窦律的长期维持可使房颤的连缀现象逐渐消失。 * * Atrial Fibrillation Atrial fibrillation is a rapid, irregular, and even chaotic form of atrial tachyarrhythmia with an irregular ventricular response. It has recently been determined that a large percentage of patients with atrial fibrillation have a rapidly firing ectopic focus located in vicinity of the left superior pulmonary vein. On the ECG, note the lack of discernible P waves, and the irregularly irregular R waves. A ripple of chaotic atrial depolarization may be visible. * Atrial Fibrillation: Ablation of Pulmonary Venous Focus An ablation catheter is advanced across the atrial septum into the left superior pulmonary vein, where the ectopic focus is located. The fluoroscopy images below show the ablation catheter (ABL) in the left anterior oblique (LAO) and right anterior oblique (RAO) projections. * Identification of the PV ostium * * In this right lateral view of sinus rhythm, you can see the tracking virtual (e.g., icon that appears like a burning bush). Note the relationship between this pattern and the ECG waveform. The tracking virtual represents the peak negative voltage at this point in time and in this case represents depolarization. (The white indicates depolarization.) The numbers represent electrodes that are swiped (i.e., placed or arranged) on the chamber surface to represent electrical data within the chamber (virtual electrograms). The unipolar electrical data is displayed in yellow. The isopotential map is based on unipolar information. Unipolar signals are differentiated from a bipolar signals based on the greater distance between the two poles. Morphology is a known. On the right lateral view, note how sinus rhythm breaks out on the high lateral wall. As activation travels down the lateral wall, it split