洋地黄中毒揭示快频率依赖性束支阻滞1例

1病例介绍 　　病人,女,65岁,反复心悸8年,水肿1年,复发3周入院.临床诊断:冠心病,二尖瓣狭窄并关闭不全,心功能Ⅳ级.以往查心电图均为完全性左束支阻滞(CLBBB).入院后每日服地高辛0.25 mg,连服3个月.后改用西地兰0.2 mg或0.4 mg,每晚静脉注射1次.用后第6日晨心率突然减慢至58/min,心律不齐,09:00急查心电图示房颤,貌似高度房室传导阻滞(A-VB)致房室分离,房室交界性逸搏心律伴快频率依赖性左右束支交替型阻滞,频发室性早搏时呈二联律,QRS波时限及形态正常时,ST段呈鱼钩状.诊断洋地黄中毒[1].经停用西地兰,给予补钾等治疗后,16:00复查心电图,V6连续记录见室性早搏消失,但仍呈房颤,P波消失,代之以F波,间距长短不等,当R-R间距缩短至1.2 s,心室率增至53/min时,呈完全性右束支阻滞(CRBBB)型,RB系室内差异性传导:R-R间距＜0.12 s,心室率快于53/min时,QRS均呈CLBBB(R3-9.14),为房颤伴快频率依赖性左右束支交替型阻滞.2 d后复查心电图示为窦性心律,心率81/min,律齐,CLBBB伴Ⅰ度A-VB,QRS时间增宽,其他改变同入院时. 　　……     

Repetitive intermittent left bundle branch block

A 32-year-old woman with no structural heart disease was referred for evaluation due to daily occasional palpitations and documented left bundle branch block (LBBB) on surface electrocardiogram (EKG). Continuous 24-hour Holter monitoring revealed a broad range of repetitive intermittent LBBB grades with a rate-dependent pattern that was also associated with circadian variations.