Table 2.
Clinical, ECG, and invasive electrophysiology study characteristics by HCM etiologic group.
| Overall (n = 28) |
Storage disorder (n = 8) |
Metabolic disease (n = 5) |
Genetic syndrome (n = 5) |
Isolated (n = 10) |
p-value | |
|---|---|---|---|---|---|---|
| Clinical Characteristics | ||||||
| Age at preexcitation diagnosis (years) | 9.5 (0.0–17.2) | 14.6 (7.2–17.2) | 3.4 (0.5–10.7) | 1.3 (0.0–12.9) | 11.6 (1.7–17.0) | 0.008 |
| Age at HCM diagnosis (years) | 11.2 (0.0–19.3) | 13.4 (0.0–17.2) | 0.3 (0.0–5.7) | 11.0 (0.0–14.4) | 13.0 (0.9–19.3) | 0.048 |
| Male sex | 15 (52) | 2 (25) | 4 (80) | 2 (40) | 7 (70) | 0.188 |
| Family history of preexcitation | 7 (25) | 2 (25) | 3 (60) | 0 (0) | 2 (20) | 0.222 |
| Family history of HCM | 8 (29) | 2 (25) | 1 (20) | 2 (40) | 3 (30) | 1.000 |
| *Atrial fibrillation | 6 (21) | 4 (50) | 0 (0) | 0 (0) | 2 (20) | 0.126 |
| *Reentrant SVT | 6 (21) | 1 (13) | 1 (20) | 1 (20) | 3 (30) | 0.916 |
| Syncope | 2 (7) | 0 (0) | 1 (20) | 0 (0) | 1 (10) | 0.499 |
| ECG Characteristics | ||||||
| PR interval | 93 (55–145) | 95 (80–116) | 82 (55–90) | 88 (80–108) | 107 (65–145) | 0.121 |
| QRS duration | 110 (85–192) | 120 (95–192) | 108 (100–140) | 100 (85–108) | 110 (96–160) | 0.057 |
| DWA 40 ms after delta onset (mm) | 4.6 (1.1–22.5) | 8.2 (4.1–22.5) | 5.4 (2.8–11.5) | 4.8 (2.5–7.3) | 3.3 (1.1–15.3) | 0.013 |
| QRS ampltiude (average V1 and V6, mm) | 28.3 (10.6–79.9) | 42.3 (22.8–79.9) | 18.3 (14.4–47.0) | 28.8 (11.6–47.5) | 25.7 (10.6–34.2) | 0.049 |
| V6 R-wave amplitude (mm) | 25.2 (4.4–65.0) | 39.7 (11.6–65.0) | 16.4 (4.4–46.3) | 28.8 (11.0–44.0) | 17.5 (11.4–35.1) | 0.062 |
| Normalized V6 R-wave amplitude | 1.0 (0.3–2.5) | 1.6 (0.5–2.5) | 0.6 (0.3–2.0) | 1.1 (0.5–1.8) | 0.7 (0.4–1.5) | 0.046 |
| V1 S-wave amplitude (mm) | 20.7 (0.0–75.3) | 31.8 (0.0–75.3) | 18.4 (5.9–40.9) | 9.2 (2.6–30.5) | 20.3 (0.0–30.5) | 0.194 |
| Normalized V1 S-wave amplitude | 1.0 (0.0–3.1) | 1.3 (0.0–3.1) | 0.8 (0.2–2.0) | 0.4 (0.1–1.3) | 0.9 (0.0–1.4) | 0.237 |
| EPS Characteristics | Overall (n = 22) |
Storage disorder (n = 8) |
Metabolic disease (n = 3) |
Genetic syndrome (n = 2) |
Isolated (n = 9) |
|
| Patients with AP with anterograde conduction | 14 (64) | 5 (63) | 2 (66) | 2 (100) | 5 (66) | 0.912 |
| Patients with multiple true APs | 8 (36) | 2 (25) | 1 (33) | 0 (0) | 5 (56) | 0.470 |
| Patients with high risk true AP | 5 (23) | 1 (13) | 1 (33) | 1 (50) | 2 (22) | 0.653 |
| Patients with FVF | 16 (73) | 7 (88) | 1 (33) | 2 (100) | 6 (66) | 0.307 |
| Patients with FVF-mediated preexcitation | 8 (36) | 3 (38) | 1 (33) | 0 (0) | 4 (44) | 0.912 |
Data expressed n (%) or median (range); n = number of patients
*
One patient had both SVT and AF
AF = atrial fibrillation, AP = accessory pathway, DWA = delta wave amplitude, EPS = electrophysiology study, HCM = hypertrophic cardiomyopathy, SVT = supraventricular tachycardia.