Table 3.
Clinical, echocardiographic and electrocardiographic characteristics of SCA cases with and without syncope.
| Syncope (n=143) |
No syncope (n=1976) |
P value | |
|---|---|---|---|
| Age (years) | 73.7 ± 13.1 | 68.0 ± 13.8 | < 0.0001 |
| Male | 91 (63.6%) | 1326 (67.1%) | 0.39 |
| Ethnicity | 0.62 | ||
| White | 120 (83.9%) | 1691 (86.7%) | |
| Black | 12 (8.4%) | 142 (7.3%) | |
| Other | 11 (7.7%) | 117 (6.0%) | |
| Hypertension | 109 (76.2%) | 1341 (67.9%) | 0.04 |
| Diabetes | 53 (37.1%) | 743 (37.6%) | 0.90 |
| Pulmonary disease | 43 (30.1%) | 642 (32.5%) | 0.55 |
| Chronic renal insufficiency | 41 (28.7%) | 412 (20.8%) | 0.03 |
| History of atrial fibrillation | 52 (36.4%) | 424 (21.5%) | <0.0001 |
| Medication | |||
| Beta-blockers | 72 (53.7%) | 806 (46.0%) | 0.08 |
| Antiarrhythmic | 38 (28.4%) | 321 (18.3%) | 0.004 |
| Digoxin | 24 (17.9%) | 223 (12.7%) | 0.09 |
| Diuretics | 72 (53.7%) | 817 (46.7%) | 0.11 |
| LVEF ≤35% | 23 (27.7%) | 189 (27.0%) | 0.90 |
| Left ventricular hypertrophy* | 28 (45.2%) | 185 (41.8%) | 0.68 |
| Heart rate (bpm) | 75.5 ± 17.1 | 79.1 ± 18.9 | 0.08 |
| QRS (ms) | 105.8 ± 31.4 | 103.0 ± 24.6 | 0.42 |
| QTc (ms) | 462.1 ± 43.1 | 450.7 ± 38.3 | 0.07 |
| Cardiac conduction | 0.83 | ||
| Normal conduction | 50 (54.4%) | 488 (54.5%) | |
| Low-grade conduction abnormality† | 12 (13.0%) | 99 (11.0%) | |
| High-grade conduction abnormality‡ | 30 (32.6%) | 309 (34.5%) |
Data are presented as mean ± SD or n (%). Information available on medications for 134 syncope and 1751 non-syncope cases, on LVEF for 83 syncope and 700 non-syncope cases, on left ventricular hypertrophy for 62 syncope and 443 non-syncope cases, and on electrocardiographic data for 90 syncope and 883 non-syncope cases.
Defined as echocardiographic LV mass index ≥110/m2 in women and ≥134g/m2 in men.
First-degree atrioventricular block, isolated left anterior or posterior fascicular block, or incomplete left/right bundle-branch block.
Complete left/right bundle-branch block, intraventricular conduction delay (QRS ≥120ms) or II- or III-degree atrioventricular block.
Medication information available for 134 cases with syncope and 1751 no-syncope cases.