Table 1.
Baseline Demographics and Clinical Characteristics
| Patient Characteristics | All | Not Optimized 2007–2013 | 12‐Lead ECG Optimized 2014–2017 | P Value |
|---|---|---|---|---|
| n=130 | n=63 | n=67 | ||
| Age, y | 67±12 | 66±14 | 69±11 | 0.286 |
| Sex, male | 88 (68%) | 41 (65%) | 47 (70%) | 0.577 |
| NYHA class | 0.477 | |||
| I | 1 (1%) | 1 (2%) | 0 (0%) | |
| II | 35 (27%) | 14 (22%) | 21 (31%) | |
| III | 89 (68%) | 45 (71%) | 44 (66%) | |
| IV | 5 (4%) | 3 (5%) | 2 (3%) | |
| ACE‐I/ARB use | 110 (85%) | 53 (84%) | 57 (85%) | 1.000 |
| Beta‐blocker use | 115 (88%) | 56 (89%) | 59 (88%) | 1.000 |
| QRS duration, ms | 154±20 | 156±21 | 152±19 | 0.272 |
| PR interval, ms | 181±34 | 184±39 | 178±30 | 0.400 |
| Conduction | 0.758 | |||
| LBBB | 86 (66%) | 39 (62%) | 47 (70%) | |
| RBBB | 17 (13%) | 9 (14%) | 8 (12%) | |
| IVCD | 24 (18%) | 13 (21%) | 11 (16%) | |
| RV‐paced | 3 (2%) | 2 (3%) | 1 (1%) | |
| DE characteristic | 0.235 | |||
| No DE | 45 (35%) | 18 (29%) | 27 (40%) | |
| Midwall stripe | 30 (23%) | 18 (29%) | 12 (18%) | |
| Scar | 55 (42%) | 27 (42%) | 28 (42%) | |
| Scar burden, % | 18±13 | 21±16 | 14±9 | 0.050 |
| Lateral/posterolateral LV lead | 123 (95%) | 60 (95%) | 63 (94%) | 1.000 |
| Pre‐CRT LVESV, mL | 120±57 | 120±52 | 119±62 | 0.877 |
| Pre‐CRT LVEDV, mL | 164±63 | 166±60 | 163±66 | 0.760 |
| Pre‐CRT EF, % | 29±7 | 29±7 | 29±8 | 0.639 |
ACE‐I indicates angiotensin‐converting enzyme inhibitor; ARB, angiotensin receptor blocker; DE, delayed enhancement; EF, ejection fraction; IVCD, intraventricular conduction delay; LBBB, left bundle branch block; LV, left ventricular; LVEDV, left ventricular end‐diastolic volume; LVESV, left ventricular end‐systolic volume; NYHA, New York Heart Association; RV, right ventricular.