Introduction
Catheter ablation of ventricular arrhythmias is often performed in patients with severe and multiple cardiovascular diseases requiring intermediate or intensive care on dedicated units (IMC/ICU). The frequency of IMC and ICU usage after ablation of ventricular arrhythmias is not known.

Methods
Consecutive patients referred for catheter ablation of ventricular arrhythmias between 2019 and 2021 were included into the analysis. Patients with postinterventional necessity of IMC/ICU treatment were analysed regarding risk factors and acute outcome; patients with IMC/ICU treatment prior to ablation were excluded from the analysis. Data are presented as mean±standard deviation or median (interquartile range (IQR)).

Results
A total of 499 patients were analysed. Of these, fifty-one were excluded from further analysis due to treatment on IMC or ICU prior to ablation. Mean age of the analysis population (n=448) was 61±15 years, 70.3% were male. Admission to IMC/ICU was required in 8.3% of patients. The reasons for postinterventional admission to IMC/ICU were recovery from general anaesthesia or multimorbidity (n=19), pericardial effusion (n=10), cardiogenic shock (n=5), groin hematoma (n=1), temporary bradycardia (n=1) or planned implantation of an assist device (Impella®) during procedure (n=1). Median length of IMC/ICU stay was 3.5 days (IQR 9). Almost all patients with postinterventional IMC/ICU treatment (91.9%) suffered from structural heart disease compared to 58.1% of patients without higher postinterventional care (p<0.01). Furthermore, patients with IMC/ICU treatment were more often treated for ventricular tachycardia (81.1% of patients) than for premature ventricular contractions, while controls were more often treated for premature ventricular contractions (59.4%, p <0.01). Chronic kidney disease (51.1% vs. 27.0%; p <0.01) and chronic pulmonary disease (35.1% vs. 18.2%; p=0.01) were more often observed in patients with postinterventional IMC/ICU treatment. One patient with postinterventional care on ICU died during the hospital stay (complicated postinterventional course with pericardial effusion, septic shock in combination with end stage heart failure). Recurrence of ventricular tachycardia was not different between groups (18.9% vs. 14.3 %, p=0.467).

Conclusion
IMC or ICU stay after ablation is required in 8.3% of patients undergoing catheter ablation of ventricular arrhythmias. IMC or ICU stay is associated with structural heart disease, chronic kidney and pulmonary disease, but not with recurrent ventricular tachycardia.