[Predictive values for slow pathway modification of atrioventricular nodal reentrant tachycardia]

The predictive values of various ECG parameters for slow pathway modification were studied in 42 slow-fast AVNRT patients. The negative predictive values of a stable ECG, junctional rhythm, and slow pathway potential were as high as 94.8%, 94.9% and 84.9% respectively. But, their positive values were 29.4%, 15.1% and 23.9%. The possibility of success (PS) raised with increasing of width and peak number of A wave. When the width of A wave was > or = 80ms, PS was 50%. When the peak number of A wave was > 7, PS was 80%. A/V ratio varied from 0.14 to 1 in 93.2% of successful sites. When A/V ratio was 0.25, PS reached its peak value of 33.3%.