Table 4.
ECG data.
| All N = 301 | Apical HCM N = 80 | Septal HCM N = 221 | P-value | |
|---|---|---|---|---|
| Heart rate, bpm | 64 (12) | 65 (12) | 64 (13) | 0.81 |
| PR interval, ms | 178 (46) | 170 (40) | 181 (49) | 0.01 |
| QRS duration, ms | 100 (26) | 98 (24) | 104 (34) | 0.02 |
| QTc duration, ms | 446 (43) | 446 (43) | 446 (43) | 0.93 |
| LBBB, n (%) | 44 (15) | 1 (1, 2) | 43 (19, 4) | <0.001 |
| RBBB, n (%) | 30 (10) | 4 (5) | 26 (11, 8) | 0.52 |
| Ventricular paced QRS, n (%) | 37 (12) | 7 (8, 7) | 30 (13, 5) | 0.43 |
| Precordial T-wave inversion V4–V6$, n (%) | 103 (34%) | 50(62,5) | 52 (23, 5) | 0.001 |
| Maximal precordial T-wave inversion, mm | 3 ± 4.5) | 5.2 ±3,6 | 3.2 ± 2.3 | 0.39 |
| ER pattern in HCM | ||||
| Eligible ECGs for analysis¶, n (%) | 139 (46) | 52 (65) | 87 (39) | 8,12 |
| Presence of any ER pattern, n (%)# | 29 (21) | 10 (7) | 19 (14) | 0.41 |
| Presence ERP inferior lead# | 20 (14) | 6 (4) | 14 (10) | 0,72 |
| Maximal J-point elevation, mm | 1.5 (1) | 2 (2) | 1 (0.75) | 0.03 |
Continuous variables are presented as mean ± SD or median (interquartile range, IQR) where appropriate.
QTc, corrected QT interval; LBBB, left bundle branch block; RBBB, right bundle branch block; ER, early repolarization; LV, left ventricular.
¶
To determine the presence of early repolarization pattern all ECGs with QRS ≥ 110 ms or paced QRS were excluded.
#
Percentage of eligible ECGs for ER analysis.
$
Excluding ECGs with ventricular paced QRS, LBBB or LBBB-like non-specific intraventricular conduction delay.