1例32岁女性患者因反复心悸及静息心电图表现为预激而就诊。超声心动图和心脏MRI检查除后者显示左心室质量略增大外,均在正常值内。患者诉劳力性呼吸困难,但无晕厥和先兆晕厥。动态心电图监测显示频发室性异位搏动而无持续性心动过速,窦性心动过缓心率从36次/min到96次/min,无明显停搏。运动试验时预激不消失,但达到的最大心率只有96次/分(预期的51%)。基础心电图显示窦性心律、短P-R A 32-year-old female patient presented with pre-excitation due to repeated palpitations and resting ECG. Echocardiography and cardiac MRI in addition to the latter showed a slight increase in left ventricular mass, are within the normal value. Patients complained of exertional dyspnea but no syncope or threatened syncope. Holter monitoring showed frequent ventricular ectopic beats without sustained tachycardia, sinus bradycardia heart rate from 36 beats / min to 96 beats / min, no significant arrest. Exercise test does not disappear when the pre-excitation, but reached a maximum heart rate of only 96 beats / min (51% of the expected). Basic electrocardiogram shows sinus rhythm, short P-R