| Inappropriate shocks | No inappropriate shocks | p Value | |
| Age, mean (SD) | 37 (21) years | 46 (16) years | 0.01 |
| Age <35 years | 21 (50%) | 27 (20%) | <0.01 |
| Gender (male) | 29 (69%) | 81 (62%) | 0.27 |
| Ejection fraction (%), mean (SD) | 69 (10) | 68 (10) | 0.56 |
| Ejection fraction <50% | 2 (5%) | 7 (5%) | 0.99 |
| LVOT gradient, mean (SD) | 31.78 (41.01) mm Hg | 23.76 (30.91) mm Hg | 0.27 |
| LVOT gradient >36 mm Hg | 11 (29%) | 25 (19%) | 0.20 |
| Septal thickness, mean (SD) | 20.39 (6.03) mm | 21.11 (6.85) mm | 0.54 |
| Septal thickness ⩾30 mm | 4 (11%) | 19 (15%) | 0.31 |
| DFT at implant | 13 (6) J | 14 (5) J | 0.31 |
| DFT >15 J | 10 (25%) | 34 (26%) | 0.92 |
| Beta blocker use | 30 (71%) | 89 (64%) | 0.37 |
| Atrial fibrillation | 24 (57%) | 55 (40%) | 0.04 |
| Dual-chamber implantable cardioverter defibrillator | 22 (52%) | 86 (62%) | 0.27 |
| Myectomy | 14 (33%) | 58 (42%) | 0.29 |
| Septal ablation | 1 (2%) | 9 (7%) | 0.26 |
| Primary prevention | 34 (81%) | 121 (87%) | 0.34 |
| ⩾2 risk factors | 17 (52%) | 54 (45%) | 0.51 |
DFT, defibrillation threshold testing; LVOT, left ventricular outflow tract.