Unsynchronized atrioventricualr activation during atrioventricular nodal reentranttachycardia (AVNRT) were seen in 13 patients, 11 of which had 2: 1 AV conduction, 2 AV dissocua-tion.

• 13倒房室结折返性心动过速（AVNRT），其心动过速时表现为房室非同步兴奋，其中房室2：1传导11例，房室分离2例。