Monitoring of Ventricular Tachyarrhythmias in Patients With Implantable Cardioverter-Defibrillators

Objective: To assess the risk of tachyarrhythmia during implantation of a cardioverter defibrillator Design and method: A retrospective analysis was performed on data from 93 patients with Biotronik implantable cardioverter-defibrillators implanted (75 men (80.6%) and 18 women (19.3%) aged 40 to 83 years). The mean age was 61.9 ± 7.8 years for men and 61.8 ± 7.9 years for women. Depending on the prescribed therapy, patients were divided into the following groups: 71 patients received antiarrhythmic drug (AAD) monotherapy, 15 received combined AAD therapy, and 7 patients did not receive AADs. Results: Episodes of ventricular tachycardia or ventricular fibrillation (VT/VF) were observed in 27.9% of patients receiving antiarrhythmic therapy and in 28.5% of patients without AAD therapy (p = 1.0). The incidence of VT/VF in patients treated with bisoprolol was 20% and increased more than twofold with higher doses, reaching 50%. In patients receiving carvedilol at a dose of 6.25 mg, VT/VF occurred in 33.3% of cases. Among patients of the combination therapy group who received sotalol, the incidence of VT/VF was 66.6%. Quadruple therapy was administered to 69.8% of patients and was associated with a reduction in VT/VF incidence from 50% to 21% (p < 0.05). Relative risk analysis (RR = 0.503) demonstrated a 49.7% risk reduction, while the risk difference (RD = 0.213) indicated that quadruple therapy prevented VT/VF episodes in 21.3% of patients compared with those not receiving the full regimen. The number needed to treat (NNT = 4.69) suggests that approximately five patients must be treated to prevent one VT/VF episode. Conclusions: In contrast, quadruple heart failure therapy significantly reduced the frequency of VT/VF episodes from 50% to 21%, indicating its clinical effectiveness in arrhythmia risk reduction. A relative risk of 0.503 (p < 0.05) confirms a 49.7% reduction in VT/VF risk with quadruple therapy, with an NNT of 4.7, underscoring the clinical relevance of multidrug therapy.