Follow up
Median follow-up was 478 days (IQR 225-567). All patients showed stable electrical parameters at last follow-up. The ventricular pacing threshold remained stable from implant (0.85±0.61V) to last follow-up (0.99±0.68 V, p=0.38) with a maximum increase of 0.75V in patient #4. No complications were registered during the follow-up. Systemic ventricle systolic function showed a significant improvement in patients with a systemic LV (n=16 patients)(LV ejection fraction assessed by biplane Simpson’s method: 51±16% at baseline vs. 55±17 at last follow-up, p=0.031), and also in patients with a systemic right ventricle (n=6 patients)(fractional area change: 39±13% at baseline vs. 43±15% at last follow-up, p=0.021) (Figure 4). NYHA class significantly improved during follow-up from 1.50±0.51 to 1.10±0.31 (p=0.008). Nine patients had symptomatic heart failure at baseline (NYHA class II) and improved to NYHA class I at last follow-up.