Baseline characteristics
| All patients (n=27) | Acute CRT non-responders (n=9) | Acute CRT responders (n=18) | P value | |
| Age (years) | 64±9 | 68±9 | 62±8 | 0.09 |
| Male gender (n) | 21 (78) | 8 (89) | 13 (72) | 0.63 |
| CAD (n) | 15 (56) | 5 (56) | 10 (56) | 1.0 |
| LV EDV(mL) | 269±116 | 276±125 | 265±114 | 0.83 |
| LV ESV (mL) | 199±101 | 197±104 | 200±102 | 0.95 |
| LVIDd (mm) | 68±9 | 70±12 | 67±8 | 0.40 |
| LVIDs (mm) | 61±10 | 62±13 | 60±8 | 0.73 |
| LV FS (%) | 10±5 | 12±5 | 10±4 | 0.19 |
| LV EF (%) | 28±6 | 30±5 | 27±7 | 0.24 |
| LBBB (n) | 26 (96) | 9 (100) | 17 (94) | 1.0 |
| QRS width (ms) | 173±18 | 169±25 | 176±14 | 0.39 |
| Q-LV (ms) | 126±24 | 129±33 | 125±18 | 0.69 |
| Intrinsic heart rate (beats per minute) | 68±8 | 63±3 | 71±9 | 0.01 |
| Intrinsic AV interval (ms) | 279±47 | 289±53 | 274±44 | 0.47 |
| NYHA class II (n) | 11 (41) | 3 (33) | 8 (44) | 0.69 |
| NYHA class III (n) | 16 (59) | 6 (67) | 10 (56) | 0.69 |
| ACE inhibitors/ARB (n) | 27 (100) | 9 (100) | 18 (100) | 1.0 |
| Beta blockers (n) | 27 (100) | 9 (100) | 18 (100) | 1.0 |
| Aldosterone inhibitors (n) | 18 (67) | 6 (67) | 12 (67) | 1.0 |
| Loop diuretics (n) | 20 (74) | 6 (67) | 14 (78) | 0.65 |
ARB, angiotensin receptor blocker; AV, atrioventricular; CAD, coronary artery disease; CRT, cardiac resynchronisation therapy; EDV, end diastolic volume; EF, ejection fraction; ESV, end systolic volume; FS, fraction shortening; LBBB, left bundle branch block; LV, left ventricular; LVIDd, left ventricular internal end diastolic diameter; LVIDs, left ventricular internal end systolic diameter; NYHA, New York Heart Association; Q-LV, time interval from the beginning of QRS to LV sense.