Table 2. – Comparison of results before and after permanent pacemaker implantation.
| DDD-Var | DDD-His | p | |
|---|---|---|---|
| Synchrony index | n=34 | n=17 | |
| Preintervention*; n(%) | 0.001 | ||
| Synchronous | 8 (23.5)a | 12 (70.6)b | |
| Intermediate | 3 (8.8)a | 2 (11.8)a | |
| Asynchronous | 23 (67.6)a | 3 (17.6)b | |
| Postintervention; n(%) | 0.560 | ||
| Synchronous | 33 (97.1) | 16 (94.1) | |
| Intermediate | 1 (2.9) | - | |
| Asynchronous | - | 1 (5.9) | |
| imeSI value | |||
| Pre*; median (min-max) | 1.00 (0.12 to 1.00) | 0.21 (0.06 to 1.00) | 0.001 |
| Post; median (min-max) | 0.18 (0.11 to 0.70) | 0.18 (0.11 to 0.72) | 0.461 |
| %variation**; median (min-max) | -74 (-89 to 192) | 0 (-77 to 243) | <0.001 |
| Post-implantation ECG | n=34 | n=17 | |
| Axis; n(%) | 0.074 | ||
| Physiological | 26 (76.5) | 8 (47.1) | |
| Probably physiological | 8 (23.5) | 9 (52.9) | |
| Pacing | n=34 | n=17 | |
| Category (%) | 0.915 | ||
| Physiological | 15 (44.1) | 6 (35.3) | |
| Probably physiological | 16 (47.1) | 9 (52.9) | |
| Probably not physiological | 3 (8.8) | 2 (11.8) | |
| Missing physiological pacing criterion; n(%) | n=19 | n=11 | |
| RWPT ≥100 ms | 5 (26.3) | 6 (54.5) | 0.238 |
| Plateau in lead D1 | 12 (63.2) | 4 (36.4) | 0.299 |
| Notching in lead V1 | 5 (27.8) | 3 (27.3) | 0.999 |
AVB: atrioventricular block; ECG; electrocardiogram; imeSI: immediate synchrony index; RWPT: R-wave peak time. Synchronous: imeSI ≤ 0.40; intermediate: imeSI 0.41-0.70; asynchronous: imeSI ≥ 0.71. Associations between categorical variables were tested with Fisher's exact test or the chi-square test with Yates correction, while associations between quantitative variables with asymmetric distribution were tested with the Mann Whitney test. **% variation=([post value - pre value]/pre value*100); a,b: different letters indicate significantly different percentages.