Objective In order to avoid and decrease inappropriate discharge caused by implantable cardioverter defibrillators (ICD), we analysed the cause of inappropriate discharge.

Methods Clinical follow-up data of inappropriate discharges by ICD in 6 patients were studied. All the 6 patients were male, 2 were dual chamber ICD, while 7 were single chamber ICD. The patients were followed-up from 0.5 to 9 (averaged 4.5) years.

Results During follow-up, all the patients survived. Arrhythmias were detected 358 times, ICD treatment was performed 71 times, inappropriate discharges occurred 14 times. 2 patients who implanted ICD earlier experienced all the 14 inappropriate discharges. The causes of inappropriate discharges include oversensing sinus tachycardia (3 times), electromagnetic interference (2 times), lead insulation breaks (9 times). They accounted for 21.4%, 14.2%, 64.2% of total inappropriate discharges, respectively.

Conclusion Inappropriate discharge of ICD should be taken seriously consideration.