Incidence of VA in the study population
As depicted in Figure 1, the final cohort consist of 455 patients; mean age was 64.9 ± 15.7 years. 24.3% of them were females . Table 1 presents patients characteristics. More frequent etiologies of heart diseases leading to implant were ischemic heart disease (40.2%), dilated non-ischemic cardiomyopathy (32.5%), hypertrophic cardiomyopathy (9.2%), Brugada syndrome (3.5%) and arrhythmogenic right ventricular cardiomyopathy/dysplasia (1.2%).
Among study population, 163 patients (35.8%) had single chamber ICD, 75 (16.5%) had a dual chamber ICD, 37 (8.1%) a subcutaneous ICD and 180 patients (39.6%) had a CRTD implanted.
Most of patients received a defibrillator for primary prevention (358 patients – 79.2%). Device settings were variably programmed, with 205 (45.4%) with an enabled monitor zone (mean cut-off value 156.2 ± 13.68 beats per minute - bpm), 18.4 % with a VT zone (mean cut-off value 182.7 ± 20.9 bpm) and 100% having a VF zone (mean cut-off value 206.6 ± 15.8 bpm).
Within the study cohort 89 patients (19.6%) had previous history of device therapy, either ATP or shocks. A vast majority of patients take beta-blockers as medication (see table 1).
Overall, 45 (9.9%) patients experienced from February 21st to April 5th 2020, a total of 86 VA: 77 episodes (89.5 %) of VTs, 9 (10.5%) VF. 8 patients (1,7 %) required ATP and 6 (1.3%) at least one shock during the study period. (see Table 1 and Figure 2)
— Figure 2 —
During reference timeframe - February 21st to April 5th 2019 - the number of events was 69 VA, experienced by 36 patients (7.9%): 64 episodes (92.7 %) of VTs, 5 (7.2%) VF. 6 patients (1.3%) required ATP and 3 (0.7%) at least one shock during the study period.
— Table 1 —