常用的抗心律失常药物对心肌各部分传导速度和不应期的影响极为不同。为此,对某一已经使用一种抗心律失常药物,但尚不能得到满意结果的患者,加用第二种药物不一定会得到纠治或预防心律失常的相加效 Commonly used anti-arrhythmic drugs on the part of the myocardial conduction velocity and refractory period are very different. For this reason, adding a second drug to someone who already has an antiarrhythmic drug that is not yet satisfactory, may not necessarily result in an additive effect of correcting or preventing arrhythmia