Clinical characteristics of patients with an implantable cardioverter-defibrillator: Our experience at Asan Medical Center / 대한내과학회지

ABSTRACT

BACKGROUND/AIMS: The purpose of this study was to analyze the clinical features of the patients who underwent implantable cardioverter- defibrillator (ICD) treatment. METHODS: The clinical features and the test data of the intracardiac electrograms for the patients who underwent ICD implantation between 1996 and 2005 at Asan Medical Center were retrospectively analyzed. RESULTS: One hundred thirty five patients (109 males and 26 females, a mean age of 54+/-13 years) were included in this study. The underlying cardiovascular diseases were post-myocardial infarction (MI) ventricular tachycardia (VT), Brugada syndrome, hypertrophic cardiomyopathy (CM) and dilated CM. During a mean of 2.9+/-2.0 years of follow-up, appropriate shocks were delivered in 43 (31.9%) and inappropriate shocks were delivered in 39 (28.9%) patients. Anti-tachycardia pacing therapy was effective in 17 patients. Inappropriate shocks were caused by atrial fibrillation with rapid ventricular responses, T wave oversensing or electromagnetic interference. Major complications of ICD therapy during follow-up included ICD infection, lead problems, electromagnetic interference and generator malfunction. CONCLUSIONS: The three major cardiovascular diseases in patients with ICD implantation were post MI VT, Brugada syndrome and hypertrophic CM. Inappropriate shocks were delivered to a significant proportion of the patients, which emphasize the need for an aggressive rate control strategy in patients with atrial fibrillation. Most complications of ICD therapy were caused by device malfunction.