Aim:
The primary objective of the research was to determine the incidence of appropriate and inappropriate shocks, arrhythmic storms, and recurrence of ventricular arrhythmias after the implantation. The secondary objective was to determine the risk factors to create a profile of patients at risk of appropriate and inappropriate shock.
Methodology:
We analysed 393 patients with implanted ICDs for secondary prevention between 2014 and 2018. The analysis was retrospective, with a partially prospective study until 2021. Minimal follow-up was 12 months. We observed risk factors. We analysed data from intracardial ECG to determine the incidence of ventricular arrhythmias, appropriate and inappropriate shocks, and arrhythmic storms.
Results:
Data on 393 patients with ICD for secondary prevention (mean age 73) was obtained with a mean follow-up of 49 months. The ICD was implanted in 57,8% due to VF and 39,7% due to VT. The incidence risk of VT/VF was 40,4%, with 7,1% of patients experiencing an arrhythmic storm. Appropriate shock incidence was 26,2%, while inappropriate shock incidence was 8,9%. Although the primary arrhythmia was mainly ventricular fibrillation, the arrhythmic recurrence was 89,9% sustained ventricular tachycardia. 51% of patients with arrhythmic recurrence had a ventricular arrhythmia within the first 12 months after the implantation. (Fig.1). Surprisingly, no statistically significant risk factors were found to determine appropriate or inappropriate ICD shock.
Conclusion:
During the 7-year follow-up, recurrence of ventricular arrhythmia was observed in about 40%, and mainly within the first two years after ICD implantation. Close monitoring during this period is crucial. No statistically significant risk factors for appropriate or inappropriate shocks were found.
